-
Question 1
Correct
-
The second generation antihistamine, cetirizine is a less-sedating antihistamine than the older antihistamine, chlorphenamine because:
Your Answer: It is less lipid-soluble so less able to cross the blood brain barrier.
Explanation:All older antihistamines such as chlorphenamine cause sedation. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 2
Correct
-
Regarding CSF (cerebrospinal fluid) production, approximately how much is produced per day?
Your Answer: 500 ml
Explanation:CSF fills the ventricular system, a series of interconnected spaces within the brain, and the subarachnoid space directly surrounding the brain. The intraventricular CSF reflects the composition of the brain’s extracellular space via free exchange across the ependyma, and the brain “floats” in the subarachnoid CSF to minimize the effect of external mechanical forces. The volume of CSF within the cerebral ventricles is approximately 30 mL, and that in the subarachnoid space is about 125 mL. Because about 0.35 mL of CSF is produced each minute, CSF is turned over more than three times daily. Approximately 500 mL of CSF is produced per day, at a rate of about 25 mL per hour.
CSF is a filtrate of capillary blood formed largely by the choroid plexuses, which comprise pia mater, invaginating capillaries, and ependymal cells specialized for transport. The choroid plexuses are located in the lateral, third, and fourth ventricles. The lateral ventricles are situated within the two cerebral hemispheres. They each connect with the third ventricle through one of the interventricular foramina (of Monro). The third ventricle lies in the midline between the diencephalon on the two sides. The cerebral aqueduct (of Sylvius) traverses the midbrain and connects the third ventricle with the fourth ventricle. The fourth ventricle is a space defined by the pons and medulla below and the cerebellum above. The central canal of the spinal cord continues caudally from the fourth ventricle, although in adult humans the canal is not fully patent and continues to close with age.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 3
Correct
-
You are taking care of a 55-year-old male patient who is a weightlifter. He is suspected of having a direct inguinal hernia. Where would this hernia appear?
Your Answer: Medial to the inferior epigastric artery
Explanation:A direct inguinal hernia is a form of groin hernia that occurs when abdominal viscera protrude through a weakness in the posterior wall of the inguinal canal, notably through Hesselbach’s triangle, medial to the inferior epigastric veins.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 4
Correct
-
Regarding antihistamines, which of the following statements is CORRECT:
Your Answer: Elderly patients and children are more susceptible to side effects.
Explanation:Elderly patients and children are more susceptible to side effects. Antihistamines are competitive inhibitors at the H1-receptor. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent. Antihistamines are used as a second line adjunct to adrenaline in anaphylaxis.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 5
Incorrect
-
A 56-year-old female presents at the hospital with a diabetic foot ulcer that has become infected. She has a longstanding history of type 2 diabetes mellitus and diabetic polyneuropathy. She has trouble controlling her blood sugar levels, and recently, she was converted to a new insulin regimen that includes intermediate-acting insulin.
Out of the following, which one is the intermediate-acting insulin?Your Answer: Insulin glulisine
Correct Answer: Isophane insulin
Explanation:Insulin is used mainly in type 1 diabetes, where the pancreas makes no insulin and can sometimes be prescribed in type 1 diabetes. There are different types of insulin categorized by their onset of action:
1. Intermediate-acting insulins (isophane insulin NPH):
– intermediate duration of action, designed to mimic the effect of endogenous basal insulin
– starts their action in 1 to 4 hours
– peaks in 4 to 8 hours
– dosing is usually twice a day and helps maintain blood sugar throughout the day
– Isophane insulin is a suspension of insulin with protamine2. Short-acting insulins (regular insulin)
– starts the action in 30 to 40 minutes
– peaks in 90 to 120 minutes
– duration of action is 6 to 8 hours
– taken before meals, and food is necessary within 30 minutes after its administration to avoid hypoglycaemia3. Long-acting insulins (glargine, detemir, degludec)
– start action in 1 to 2 hours
– plateau effect over 12 to 24 hours
– Dosing is usually during the night-time after meals. Their long duration of action helps in reducing the frequency of dosing throughout the day.4. Rapid-acting insulins (lispro, aspart, glulisine)
– start their action in 5 to 15 minutes
– peak in 30 minutes
– The duration of action is 3 to 5 hours
– generally used before meals and always used along with short-acting or long-acting insulins to control sugar levels throughout the day. -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
-
-
Question 6
Incorrect
-
A 7-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent non-blanching rash on legs and arms. The GP administered a dose of antibiotics before transferring child to the Emergency Department.
Which of these is the most appropriate antibiotic to administer in this scenario from the choices available?
Your Answer: Give IV benzylpenicillin 900 mg
Correct Answer: Give IM benzylpenicillin 600 mg
Explanation:Meningococcal septicaemia should be suspected in a child with a non-blanching rash especially in the presence of:
An ill-looking child
Neck stiffness
Lesions larger than 2 mm in diameter (purpura)
Capillary refill time of>3 secondsThe index child is very sick and shows signs of septic shock. In the prehospital setting, a single dose of benzylpenicillin should be given immediately. The correct dose for this childs age is IM benzylpenicillin 600 mg.
The recommended doses of benzylpenicillin according to age are:
Infants <1 year of age: IM or IV benzylpenicillin 300 mg
Children 1 to 9 years of age: IM or IV benzylpenicillin 600mg
Children and adults 10 years or older: IM or IV benzylpenicillin 1.2g -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 7
Correct
-
A patient who is taking ramipril for high blood pressure complains of a dry persistent cough. What is the mechanism of cough in ACE inhibitor therapy:
Your Answer: Decreased bradykinin breakdown
Explanation:Blocking ACE also diminishes the breakdown of the potent vasodilator bradykinin which is the cause of the persistent dry cough. Angiotensin-II receptor blockers do not have this effect, therefore they are useful alternative for patients who have to discontinue an ACE inhibitor because of persistent cough.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 8
Correct
-
Epigastric pain and haematemesis present in a 67-year-old man. In the emergency room, he is stabilised and referred to the on-call medical team. He has been scheduled for an endoscopy in the morning due to a suspected peptic ulcer. Before transferring him to the ward, you consider giving him a proton pump inhibitor (PPI).
Which of the following doses and routes are the best?Your Answer: A PPI should not be prescribed
Explanation:PPIs should not be used prior to endoscopic therapy when an early endoscopic examination is performed within 24 hours of admission, according to current recommendations.
High-dose PPI therapy reduces the risk of rebleeding and surgery after endoscopic treatment of severe peptic ulcer bleeding. Both oral and intravenous PPIs produce similar results, and there is no discernible benefit to using the intravenous formulation in patients who can tolerate oral medication. -
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
-
-
Question 9
Correct
-
At which vertebral level does the spinal cord normally end in adults?
Your Answer: L1/L2
Explanation:The spinal cord starts at the foramen magnum, where it is continuous with the medulla oblongata, which is the most caudal portion of the brainstem.
It then extends inferiorly through the vertebral canal. In adults, it usually ends at the level of the first or second lumbar vertebra.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 10
Incorrect
-
The proximal convoluted tubule (PCT) is the first part of the renal tubule and lies in the renal cortex. The bulk of reabsorption of solute occurs is the PCT and 100% of glucose is reabsorbed here.
Which of the following is the mechanism of glucose reabsorption in the PCT?Your Answer: Facilitated diffusion
Correct Answer: Secondary active transport
Explanation:Glucose reabsorption occurs exclusively in the proximal convoluted tubule by secondary active transport through the Na.Glu co-transporters, driven by the electrochemical gradient for sodium.
The co-transporters transport two sodium ions and one glucose molecule across the apical membrane, and the glucose subsequently crosses the basolateral membrane by facilitated diffusion. -
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 11
Correct
-
A patient is found to be anaemic. Which one of the following blood results would favour a diagnosis of anaemia of chronic disease rather than iron deficiency:
Your Answer: Low total iron binding capacity (TIBC)
Explanation:Anaemia of chronic disease is one of the most common causes of normocytic anaemia. The anaemia is usually mild (Hb > 90 g/L) and non-progressive. Anaemia of chronic disease is usually associated with low serum iron, low transferrin saturation, and a low total iron binding capacity (TIBC) with normal or raised ferritin which differentiates it from iron deficiency anaemia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 12
Incorrect
-
Which of the following conditions manifests hyperkalaemia as one of its symptoms?
Your Answer: Bartter’s syndrome
Correct Answer: Congenital adrenal hyperplasia
Explanation:Plasma potassium greater than 5.5 mmol/L is hyperkalaemia or elevated plasma potassium level. Among the causes of hyperkalaemia include congenital adrenal hyperplasia.
Congenital adrenal hyperplasia is a general term referring to autosomal recessive disorders involving a deficiency of an enzyme needed in cortisol and/or aldosterone synthesis. The level of cortisol and/or aldosterone deficiency affects the clinical manifestations of congenital adrenal hyperplasia. When it involves hypoaldosteronism, it can result in hyponatremia and hyperkalaemia. While hypercortisolism can cause hypoglycaemia.
The other causes of hyperkalaemia may include renal failure, excess potassium supplementation, Addison’s disease (adrenal insufficiency), renal tubular acidosis (type 4), rhabdomyolysis, burns, trauma, Tumour lysis syndrome, acidosis, and medications such as ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium.
Bartter’s syndrome is characterized by hypokalaemic alkalosis with normal to low blood pressure.
Type 1 and 2 renal tubular acidosis both cause hypokalaemia.
Gitelman’s syndrome is a defect of the distal convoluted tubule of the kidney. It causes metabolic alkalosis with hypokalaemia and hypomagnesemia.
And excessive liquorice ingestion causes hypermineralocorticoidism and hypokalaemia as well. Thus, among the choices, only congenital adrenal hyperplasia can cause hyperkalaemia
.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 13
Correct
-
Question 14
Incorrect
-
A 25-year-old guy who has had a knee-high plaster cast on his left leg for the past 5 weeks arrives at the emergency department complaining of numbness on the dorsum of his left foot and an inability to dorsiflex or evert his foot. You know that his symptoms are due to fibular nerve compression. Where is the fibular nerve located?
Your Answer: Lateral compartment of leg
Correct Answer: Neck of fibula
Explanation:Dorsiflexion and eversion of the foot are innervated by the deep fibular nerve and the superficial fibular nerve, respectively.
The common fibular nerve runs obliquely downward along the lateral border of the popliteal fossa (medial to the biceps femoris) before branching at the neck of the fibula.
Thus, it is prone to being affected during an impact injury or fracture to the bone or leg. Casts that are placed too high can also compress the fibular nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 15
Incorrect
-
The percentage of patients with hepatitis B that develop chronic infection is about:
Your Answer: 20%
Correct Answer: 10%
Explanation:With hepatitis B, about 90% of people will develop lifelong immunity after clearing the infection. Chronic hepatitis develops in about 10% of patients and this may be complicated by cirrhosis or hepatocellular carcinoma. There is a very high risk of chronic infection and hepatocellular carcinoma when there is congenital infection. The risk of this in healthy adults is only about 5%.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 16
Incorrect
-
Which of the following is considered an example of an observational study?
Your Answer: Crossover study
Correct Answer: Cohort study
Explanation:The two most common types of observational studies are cohort studies and case-control studies; a third type is cross-sectional studies.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 17
Incorrect
-
Depression of the eyeball is primarily produced by which of the following muscles:
Your Answer: Superior rectus and inferior oblique
Correct Answer: Inferior rectus and superior oblique
Explanation:Depression of the eyeball is produced by the inferior rectus and the superior oblique muscles.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 18
Correct
-
Regarding NSAIDs, which of the following statements is CORRECT:
Your Answer: Diclofenac is contraindicated in people with ischaemic heart disease.
Explanation:Due to their increased risk of cardiovascular adverse events, coxibs and diclofenac are contraindicated in people with ischaemic heart disease, cerebrovascular disease, peripheral arterial disease and mild, moderate, or severe heart failure. Other NSAIDs are only contraindicated in people with severe heart failure. Selective inhibition of COX-2 is associated with less gastrointestinal intolerance. In single doses NSAIDs have analgesic activity comparable to that of paracetamol, therefore given their side effect profile, paracetamol is preferred, particularly in the elderly. Pain relief starts soon after taking the first dose and a full analgesic effect should normally be obtained within a week, whereas an anti-inflammatory effect may not be achieved (or may not be clinically assessable) for up to 3 weeks. Mefenamic acid has only very mild anti-inflammatory properties.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 19
Correct
-
Doxycycline is indicated first line for treatment of which of the following infections:
Your Answer: Chlamydia
Explanation:Doxycycline may be used first line for chlamydia, pelvic inflammatory disease (with metronidazole and ceftriaxone), acute bacterial sinusitis, exacerbation of chronic bronchitis, moderate-severity community acquired pneumonia and high-severity community acquired pneumonia (with benzylpenicillin).
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 20
Correct
-
A 58-year-old patient presents with sputum production and worsening exertional breathlessness. A spirometry is done and his results leads to a diagnosis of obstructive lung disease with mild airflow obstruction.
What FEV1 value would correspond with mild airflow obstruction according to the NICE guidelines?
Your Answer: FEV 1 >80%
Explanation:Airflow obstruction according to the latest NICE guidelines, is defined as:
Mild airflow obstruction = an FEV 1 of >80% in the presence of symptoms
Moderate airflow obstruction = FEV 1 of 50-79%
Severe airflow obstruction = FEV 1 of 30-49%
Very severe airflow obstruction = FEV1<30%.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 21
Incorrect
-
A 55 year old man presents to ED complaining of leg weakness. Your colleague has examined the patient and suspects femoral nerve palsy. Which of the following clinical features would you LEAST expect to see on examination of this patient:
Your Answer: Loss of sensation over anterior thigh
Correct Answer: Weakness of hip extension
Explanation:Damage to the femoral nerve results in weakness of hip flexion and knee extension and loss of sensation over the anterior thigh and the anteromedial knee, medial leg and medial foot.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 22
Correct
-
A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.
Which of these anatomic structures is the most superficial structure injured in the case above?Your Answer: Camper’s fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:
Skin
Fatty layer of the superficial fascia (Camper’s fascia)
Membranous layer of the superficial fascia (Scarpa’s fascia)
Aponeurosis of the external and internal oblique muscles
Rectus abdominis muscle
Aponeurosis of the internal oblique and transversus abdominis
Fascia transversalis
Extraperitoneal fat
Parietal peritoneum -
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 23
Correct
-
All of the following statements are incorrect about insulin except:
Your Answer: Proinsulin is cleaved into insulin and C peptide.
Explanation:Proinsulin is synthesised as a single-chain peptide. A connecting peptide (C peptide) within storage granules is removed by proteases to yield insulin.
Insulin:
1. is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds.
2. is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas.
3. release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin. However, most output is driven by the rise in plasma glucose concentration that occurs after a meal.
4. effects are mediated by the receptor tyrosine kinase. -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 24
Correct
-
Intravenous glucose solutions are typically used in the treatment of all of the following situations except:
Your Answer: Hypokalaemia
Explanation:In hypokalaemia, initial potassium replacement therapy should not involve glucose infusions, as glucose may cause a further decrease in the plasma-potassium concentration. Glucose infusions are used for the other indications like diabetic ketoacidosis, hypoglycaemia, routine fluid maintenance in patients who are nil by mouth (very important in children), and in hyperkalaemia.
-
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
-
-
Question 25
Correct
-
A 30 year old man stabbed in the upper arm presents to the Emergency Department and you perform a vascular examination.
The brachial pulse can be best palpated at ?Your Answer: In the antecubital fossa, medial to the tendon of the biceps brachii
Explanation:The brachial artery can be palpated in the antecubital fossa, medial to the tendon of the biceps brachii muscle.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 26
Correct
-
Regarding relationships between two variables, what does a negative correlation coefficient indicate:
Your Answer: The two variables are inversely related
Explanation:A negative correlation coefficient means that the two variables are inversely related e.g. socio-economic class and mortality.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 27
Incorrect
-
A 35-year-old man suffers an open fracture of his forearm. The nerve that innervates the pronator quadratus muscle is damaged as a consequence of this injury.
Which of the following nerves has been damaged in this case? Select ONE answer only.Your Answer: The musculocutaneous nerve
Correct Answer: The anterior interosseous nerve
Explanation:Pronator quadratus is a small, square-shaped muscle that lies in the anterior compartment of the forearm. It arises from the distal fourth of the anterior surface of the ulna and inserts into the distal fourth of the anterior surface of the radius.
Pronator quadratus is innervated by the anterior interosseous nerve. It receives its blood supply from the anterior interosseous artery, which is a branch of the common interosseous artery, which in turn is a branch of the ulnar artery.
The main action of pronator quadratus is to assist pronator teres with pronation of the forearm. The deep fibres bind the radius and ulna together.
The pronator quadratus muscle highlighted in blue (adapted from Gray’s Anatomy) -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 28
Correct
-
Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 29
Correct
-
Which of the following comprises a negative feedback mechanism?
Your Answer: Detectors, comparators, a variable set point and effectors
Explanation:Negative feedback loops, also known as inhibitory loops, play a crucial role in controlling human health. It is a self-regulating mechanism of some sort.
A negative feedback system is made up of three main components: a detector (often neural receptor cells) that measures the variable in question and provides input to the comparator; a comparator (usually a neural assembly in the central nervous system) that receives input from the detector, compares the variable to the variable set point, and determines whether or not a response is required.
The comparator activates an effector (typically muscular or glandular tissue) to conduct the appropriate reaction to return the variable to its set point.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 30
Incorrect
-
Caseous necrosis is typically seen in which of the following:
Your Answer: Malignant hypertension
Correct Answer: Tuberculosis
Explanation:Caseous necrosis is most commonly seen in tuberculosis. Histologically, the complete loss of normal tissue architecture is replaced by amorphous, granular and eosinophilic tissue with a variable amount of fat and an appearance reminiscent of cottage cheese.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 31
Correct
-
A patient is sent in by her GP with suspected ectopic pregnancy. Tubal ectopic pregnancies occur most commonly in which part of the uterine tube:
Your Answer: Ampulla
Explanation:Ectopic pregnancy most commonly occurs in the ampulla (70% of cases).
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 32
Correct
-
Which of the following is NOT a typical feature of an abducens nerve palsy:
Your Answer: Inability to look up
Explanation:CN VI palsies result in a convergent squint at rest (eye turned inwards) with inability to abduct the eye because of unopposed action of the rectus medialis. The patient complains of horizontal diplopia when looking towards the affected side. With complete paralysis, the eye cannot abduct past the midline.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 33
Incorrect
-
Which of the following data types does a pain-scoring system represent?
Your Answer: Quantitative
Correct Answer: Ordinal
Explanation:Pain scoring systems are processes for assessing pain and the severity of illnesses that have been scientifically designed and tested. An example of ordinal categorical data is a pain scoring system.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 34
Correct
-
While on morning rounds in the medical ward, the attending physician asks a medical student about the differences between transudates and exudates and their causes. The student explains that a transudate is an excess fluid that leaks out of an intravascular compartment due to an imbalance between oncotic and hydrostatic pressures.
Which ONE of the following conditions will he mention as the cause of a transudate?Your Answer: Meig’s syndrome
Explanation:Transudative effusions are caused due to systemic causes leading to increased hydrostatic pressure or decreased oncotic pressure. These include:
1) Meig’s Syndrome (Ovarian tumour causing ascites and pleural effusion)
2) Congestive heart failure
3) Nephrotic Syndrome
4) Myxoedema
5) Cirrhosis
6) SarcoidosisAn exudate is caused by local inflammation and results from increased vascular permeability. Causes include:
1) Rheumatoid arthritis
2) Pneumonia leading to empyema
3) Malignancies
4) Pericarditis -
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 35
Correct
-
Which of the following organisms can penetrate intact skin:
Your Answer: Leptospira spp.
Explanation:Leptospirosis is a bacterial disease caused byLeptospira spp. It is the most common zoonotic infection worldwide.
It is usually contracted by exposure to water contaminated with the urine of infected animals (such as rodents, cattle, and dogs). The most important reservoirs are rodents, and rats are the most common source worldwide.
The bacteria enter the body through the skin or mucous membranes. This is more likely if the skin is broken by leptospirosis is somewhat unusual in that it can enter the body through intact skin. -
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 36
Correct
-
Regarding anaemia, which of the following statements is INCORRECT:
Your Answer: Anaemia is usually associated with a decrease in red cell 2,3 - DPG.
Explanation:Anaemia is defined as a reduction in haemoglobin concentration below the normal range for the age and sex of the individual. Children tend to have lower haemoglobin than adults, and women tend to have lower haemoglobin than men. Anaemia may occur from an actual reduction in total circulating haemoglobin mass, or with an increase in plasma volume e.g. in pregnancy, causing a dilutional anaemia. After acute major blood loss, anaemia is not immediately apparent because total blood volume is reduced and it takes up to a day for plasma volume to be replaced and hence the degree of anaemia to become apparent. The initial clinical features in acute haemorrhage are therefore a result of reduction in blood volume rather than that of anaemia. When anaemia develops slowly, the associated symptoms are often very mild as the body has time to adapt to the fall in haemoglobin. This involves mechanisms such as an increase in red cell 2,3 -diphosphoglycerate (2,3 – DPG), which shifts the oxygen dissociation curve to the right, allowing enhanced delivery of O2 to the tissues, and an increase in stroke volume and heart rate.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 37
Correct
-
You have been asked to give a tutorial on common upper limb neurology to a group of medical students. You use the example of a man falling from a balcony onto spiked fencing, sustaining a puncture wound to the axilla. This results in an injury to the musculocutaneous nerve. Which of the following clinical features would you LEAST expect to see in this patient:
Your Answer: Weakness of forearm pronation
Explanation:Flexion of the arm and flexion and supination of the forearm are weakened but not lost entirely due to the actions of the pectoralis major and deltoid, the brachioradialis and the supinator muscles respectively. There is loss of sensation over the lateral aspect of the forearm. Forearm pronation would not be affected as this is primarily produced by the pronator quadratus and pronator teres muscles, innervated by the median nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 38
Correct
-
A 7-days-old neonate is taken to the emergency department. She's pyretic, lethargic, and unresponsive, and her fontanelle has bulged. Antibiotics are started, and a lumbar puncture reveals Gram-negative rods. Which pathogen is most likely to be the cause:
Your Answer: Escherichia coli
Explanation:Among neonates, group B streptococci (GBS) are the most commonly identified causes of bacterial meningitis, implicated in roughly 50% of all cases. Escherichia coli(Gram-negative rods) accounts for another 20%. Thus, the identification and treatment of maternal genitourinary infections is an important prevention strategy.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 39
Correct
-
A 32 year old woman presents with episodes of flushing, headaches and palpitations. On examination her blood pressure is significantly elevated. Which of the following is the most likely diagnosis:
Your Answer: Pheochromocytoma
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 40
Correct
-
You see a 63-year-old man with a history of melaena and epigastric discomfort. For a few months, he's been taking aspirin.
Which of the following statements about aspirin's mechanism of action is correct?Your Answer: It inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day)
Explanation:Aspirin inhibits cyclo-oxygenase irreversibly by covalently acetylating the cyclo-oxygenase active site in both COX-1 and COX-2. The production of prostaglandin and thromboxane is reduced as a result. As a result, platelet activation and aggregation are reduced. A single dose of aspirin has a half-life of 7-10 days, which is the time it takes for the bone marrow to produce new platelets.
Aspirin only inhibits COX-1, the enzyme that produces thromboxane A2, at low doses (75 mg per day), and thus has a primarily anti-thrombotic effect.
Aspirin inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day). COX-2 is involved in the production of prostaglandins, so it has an anti-inflammatory effect at these concentrations.
Aspirin, when used as an antipyretic for a viral illness in children, can cause Reye’s syndrome. Reye’s syndrome is a potentially fatal liver disease that causes encephalopathy and liver failure.
The inability of aspirin to reduce platelet production of thromboxane A2, and thus platelet activation and aggregation, is known as aspirin resistance. Although the exact frequency and mechanism of aspirin resistance are unknown, it is thought to affect about 1% of users. Women are more likely than men to experience this phenomenon.
According to new research, taking aspirin on a regular basis lowers the risk of colorectal cancer. It may also protect against cancers of the breast, bladder, prostate, and lungs.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 41
Correct
-
A 71-year-old man treated with antibiotics for a chest infection returns with a profuse, offensive smelling diarrhoea. A diagnosis of Clostridium difficile diarrhoea is made after investigations.
The action most effective at minimizing spread to other patients is?
Your Answer: Hand washing
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.
Alcohol hand gel is not effective against Clostridium Difficile spores. Hand washing with soap and water is very essential for healthcare workers who come in contact with it.
Wearing an apron and gloves, and isolation to a side room are important contact precautions. They are, however, ineffective if hand washing is neglected.
Although oral vancomycin is the first-line treatment for C. difficile associated diarrhoea, it will not limit patient to patient spread.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 42
Incorrect
-
The 'pump handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The posterior ends of the ribs moving upwards and backwards
Correct Answer: The anterior ends of the ribs moving upwards and forwards
Explanation:Because the anterior ends of the ribs are inferior to the posterior ends, when the ribs are elevated, the anterior end moves upwards and forwards, moving the sternum upwards and forwards in turn. This ‘pump handle’ upwards and forwards movement changes the anteroposterior (AP) dimension of the thorax.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 43
Correct
-
For the treatment of his atrial fibrillation, a 59-year-old man is about to begin taking warfarin. He also takes a number of other medications.
Which of the following medications will enhance warfarin's effects?Your Answer: Erythromycin
Explanation:Many medications, including warfarin, require cytochrome P450 enzymes for their metabolism. When co-prescribing cytochrome p450 enzyme inducers and inhibitors with warfarin, it’s critical to be cautious.
Inhibitors of the cytochrome p450 enzyme potentiate the effects of warfarin, resulting in a higher INR. To remember the most commonly encountered cytochrome p450 enzyme inhibitors, use the mnemonic O DEVICES:
O– Omeprazole
D– Disulfiram
E– Erythromycin (And other macrolide antibiotics)
V– Valproate (sodium valproate)
I– Isoniazid
C– Ciprofloxacin
E– Ethanol (acute ingestion)
S- Sulphonamides -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 44
Correct
-
After collapsing at home, a 62-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is rushed to resuscitation and placed on a cardiac monitor, which reveals ventricular tachycardia. An amiodarone infusion is set up.
Which of these statements about amiodarone is correct?Your Answer: It is expressed in breast milk
Explanation:Antiarrhythmic drug amiodarone is used to treat both ventricular and atrial arrhythmias. It’s a class III antiarrhythmic that works by prolonging the repolarization phase of the cardiac action potential, where potassium permeability is normally high and calcium permeability is low.
Dronedarone is sometimes used instead of amiodarone in certain situations. Although amiodarone is more effective than dronedarone, dronedarone has fewer side effects.
Grapefruit juice inhibits the metabolism of amiodarone.
The plasma half-life of amiodarone is very long, ranging from 2 weeks to 5 months. The half-life is about 2 months on average.
Because amiodarone is excreted in breast milk, it should be avoided by breastfeeding mothers. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 45
Correct
-
A 60-year-old female presents with fatigue, easy bruising and repeated chest and skin infections for five months. She also complains about several episodes of nosebleeds over the last few days without any history of trauma.
Her complete blood count shows the following results:
Hb 9 g/dl
Total leukocyte count: 2.5x10^9/L, 1100 neutrophils/ųL
MCV 100
platelet count of 90,000/ųL.
Which one of the following conditions does this patient most likely have?Your Answer: Myelodysplastic syndrome
Explanation:Myelodysplastic syndromes are a group of clonal haematopoietic disorders which are characterised by anaemia, leukopenia and thrombocytopenia.
Patients will complain of fatigue, symptoms of thrombocytopenia such as nosebleeds and easy bleeding and a history of repeated infections due to low white blood cells (especially Neutrophils).
In Chronic lymphocytic leukaemia production of hematopoietic cells goes on for a longer time.
Folate and B12 deficiency would result in hypersegmented neutrophils and a raised MCV.
Iron deficiency anaemia would not cause neutropenia or thrombocytopenia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 46
Correct
-
For an action potential to occur, which of the following must be true:
Your Answer: Depolarisation of the membrane must reach threshold potential
Explanation:For an action potential to occur, the membrane must become more permeable to Na+and the Na+influx must be greater than the K+efflux. An action potential occurs when depolarisation of the membrane reaches threshold potential. The membrane must be out of the absolute refractory period, however an action potential can still occur in a relative refractory period but only in response to a larger than normal stimulus.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 47
Correct
-
A 29-year-old female with chronic anaemia secondary to sickle cell disease is being transfused. A few minutes after starting the blood transfusion, she develops widespread itching with urticarial rash, wheezing, nausea and chest pain. Her BP reduces to 60/40 mmHg.
What is the most appropriate treatment?Your Answer: Stop the transfusion and administer adrenaline
Explanation:Anaphylaxis transfusion reaction occurs when an individual has previously been sensitized to an allergen present in the blood and, on re-exposure, releases IgE or IgG antibodies. Patients with anaphylaxis usually develop laryngospasm, bronchospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. The transfusion should be stopped immediately and the patient should be treated with adrenaline, oxygen, corticosteroids, and antihistamines.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 48
Correct
-
A 33-year-old heavily muscled man presents with left-sided chest pain. After taking part in a powerlifting competition, he felt a painful snap at the front of his shoulder and chest. There is also the presence of bruising and swelling over the left side of his chest. A ruptured pectoralis major muscle was suspected upon examining the injured area.
Which of the following statements regarding the surface markings of the pectoralis major muscle is considered correct?Your Answer: It inserts into the lateral lip of the bicipital groove of the humerus
Explanation:The pectoralis major is the superior most and largest muscle of the anterior chest wall. It is a thick, fan-shaped muscle that lies underneath the breast tissue and forms the anterior wall of the axilla.
Its origin lies anterior surface of the medial half of the clavicle, the anterior surface of the sternum, the first 7 costal cartilages, the sternal end of the sixth rib, and the aponeurosis of the external oblique of the anterior abdominal wall.
The insertion of the pectoralis major is at the lateral lip of the intertubercular sulcus of the humerus. There are 2 heads of the pectoralis major, the clavicular and the sternocostal, which reference their area of origin.
The function of the pectoralis major is 3-fold and dependent on which heads of muscles are involved:
– Flexion, adduction and medial rotation of the arm at the glenohumeral joint
– Clavicular head causes flexion of the extended arm
– Sternoclavicular head causes extension of the flexed armArterial supply of the pectoralis major, the pectoral artery, arises from the second branch of the axillary artery, the thoracoacromial trunk.
The 2 heads of the pectoralis major have different nervous supplies. The clavicular head derives its nerve supply from the lateral pectoral nerve. The medial pectoral nerve innervates the sternocostal head. The lateral pectoral nerve arises directly from the lateral cord of the brachial plexus, and the medial pectoral nerve arises from the medial cord.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 49
Correct
-
A 4-year-old child has been convulsing for 20 minutes. She has received two doses of lorazepam. She takes phenytoin for maintenance therapy, and you draw up a phenobarbitone infusion.
What dose of phenobarbitone is advised in the treatment of the convulsing child that reaches that stage of the APLS algorithm? Select ONE answer only.Your Answer: 20 mg/kg over 30-60 minutes
Explanation:If a convulsing child reaches step 3 of the APLS algorithm, then a phenytoin infusion should be set up at 20 mg/kg over 20 minutes. If they are already taken phenytoin as maintenance therapy, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 50
Correct
-
A 71-year-old woman is treated with co-amoxiclav for a chest infection but she returns 1 week later. Her chest infection has resolved but she developed a profuse, offensive smelling diarrhoea and abdominal cramps. You suspect Clostridium difficile associated diarrhoea (CDAD).
ONE of these statements is true concerning this diagnosis.Your Answer: The gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.
Alcohol hand gel is not effective against Clostridium Difficile spores. Hand washing with soap and water is very essential for healthcare workers who come in contact with it.
Currently, the gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay. Stool culture to detect Clostridium difficile is not specific for pathogenic strains, is expensive and therefore not specific for a diagnosis of CDAD
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 51
Incorrect
-
A 30-year old male is brought to the emergency room after a terrible fall during a photoshoot. The patient reported falling on his right forearm. There is evident swelling and tenderness on the affected area, with notable weakness of the flexor pollicis longus muscle. Radiographic imaging showed a fracture on the midshaft of the right radius.
Which of the following nerves is most likely injured in the case above?Your Answer: The musculocutaneous nerve
Correct Answer: The anterior interosseous nerve
Explanation:Flexor pollicis longus receives nervous supply from the anterior interosseous branch of median nerve, derived from spinal roots C7 and C8.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 52
Correct
-
A 47-year-old woman comes in with palpitations that have been bothering her for the past four days. Her haemodynamics are normal, but her heart rate is currently 150 beats per minute. An ECG is performed, which reveals that she is experiencing atrial flutter. The patient is examined by a cardiology registrar, who recommends starting her on verapamil to control her ventricular rate while she waits for cardioversion.
In these circumstances, which of the following is a contraindication to the use of verapamil?Your Answer: Acute porphyria
Explanation:In most cases of atrial flutter, ventricular rate control is used as a stopgap measure until sinus rhythm is restored. A beta-blocker (e.g. bisoprolol), diltiazem, or verapamil can be used to reduce the rate of contractions in the heart.
Electrical cardioversion, pharmacological cardioversion, and catheter ablation can all be used to return the heart to a normal rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or it has lasted longer than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is a sudden onset of symptoms and haemodynamic compromise. For recurrent atrial flutter, catheter ablation is preferred.Verapamil is a calcium-channel blocker that is non-dihydropyridine phenylalkylamine and can be used to treat supraventricular arrhythmias. It’s a calcium channel blocker with a high negative inotropic effect that lowers cardiac output, slows the heart rate, and may impair atrioventricular conduction. At high doses, it can cause heart failure, exacerbate conduction disorders, and cause hypotension.
Adults should take 240-480 mg of verapamil in 2-3 divided doses. 5-10 mg IV over 30 seconds is the corresponding intravenous (IV) dose. After an IV injection, the peak effect lasts 3-5 minutes, and the action lasts 10-20 minutes.
Verapamil should not be taken with beta-blockers like atenolol or quinidine because the combination of their negatively inotropic and negatively chronotropic effects can result in severe hypotension, bradycardia, impaired atrioventricular conduction, heart failure (due to impaired cardiac contractility), and sinus arrest.
The use of verapamil is contraindicated in the following situations:
Acute porphyrias are a type of porphyria that occurs suddenly.
Accessory conducting pathways are linked to atrial flutter or fibrillation (e.g. Wolff-Parkinson-White-syndrome)
Bradycardia
Shock caused by the heart
Insufficiency of the heart (with reduced ejection fraction)
Left ventricular function has been significantly harmed in the past (even if controlled by therapy)
Hypotension (blood pressure less than 90 mmHg)
AV block in the second and third degrees
Sinusitis is a condition in which the sinuses become
Sino-atrial occlusion -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 53
Correct
-
What is the approximate lifespan of the mature erythrocyte:
Your Answer: 120 days
Explanation:Erythrocytes have a normal lifespan of about 120 days. Mature erythrocytes are biconcave discs with no nucleus, ribosomes or mitochondria but with the ability to generate energy as ATP by the anaerobic glycolytic pathway. The red cell membrane consists of a bipolar lipid layer with a membrane skeleton of penetrating and integral proteins anchoring carbohydrate surface antigens. The shape and flexibility of red cells allows them to deform easily and pass through capillaries.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 54
Correct
-
Angiotensin II is part of the RAAS system. One of its effects is the constriction of efferent arterioles. Which of the following best describes the effect of angiotensin II- mediated constriction of efferent arterioles?
Your Answer: Decreased renal plasma flow, increased filtration fraction, increased GFR
Explanation:The Renin-Angiotensin-Aldosterone System (RAAS) is a hormone system composed of renin, angiotensin, and aldosterone. Those hormones are essential for the regulation of blood pressure and fluid balance.
Cases of hypotension, sympathetic stimulation, or hyponatremia can activate the Renin-angiotensin-aldosterone system (RAAS). The following process will then increase the blood volume and blood pressure as a response.
When renin is released it will convert the circulating angiotensinogen to angiotensin I. The ACE or angiotensin-converting enzyme will then catalyst its conversion to angiotensin II, which is a potent vasoconstrictor. Angiotensin II can constrict the vascular smooth muscles and the efferent arteriole of the glomerulus.
The efferent arteriole is a blood vessel that delivers blood away from the capillaries of the kidney. The angiotensin II-mediated constriction of efferent arterioles increases GFR, reduces renal blood flow and peritubular capillary hydrostatic pressure, and increases peritubular colloid osmotic pressure, as a response to its action of increasing the filtration fraction.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 55
Correct
-
A 25 year old woman who is a known diabetic is brought to the ED with diabetic ketoacidosis. She promptly received an insulin infusion. Which of the following are expected to increase upon infusion of insulin?
Your Answer: Blood pH
Explanation:Ketoacidosis is characterized by hyperglycaemia, glycosuria, hyperkalaemia, and metabolic acidosis with respiratory compensation. An insulin infusion would be able to address these by lowering blood glucose through increased insulin-mediated cellular uptake, lowering urine glucose concentration as cellular glucose uptake is increased, decreasing K+ in her blood by shifting it into cells, and increasing blood ph by addressing the metabolic acidosis. The metabolic acidosis is addressed by the reduction of ketoacids production thereby returning her blood ph to normal and reducing the need for compensatory hyperventilation.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 56
Correct
-
The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of lymphocyte clonal proliferation. Which of the following statements about CLL is CORRECT?
Your Answer: It is most commonly discovered as an incidental finding
Explanation:CLL (chronic lymphocytic leukaemia) is the most common type of chronic lymphoid leukaemia, with a peak incidence between the ages of 60 and 80. It is the most common type of leukaemia in Europe and the United States, but it is less common elsewhere.
The CLL tumour cell is a mature B-cell with low immunoglobulin surface expression (IgM or IgD). The average age at diagnosis is 72 years, with only 15% of cases occurring before the age of 50.
The male-to-female ratio is about 2:1. Over 80% of cases are identified by the results of a routine blood test, which is usually performed for another reason.
Lymphocytic anaemia, thrombocytopenia, and normochromic normocytic anaemia are common laboratory findings. Aspiration of bone marrow reveals up to 95% lymphocytic replacement of normal marrow elements.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 57
Correct
-
Regarding propofol, which of the following statements is INCORRECT:
Your Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 58
Correct
-
Which of the following statements is correct about the extensor digitorum muscle?
Your Answer: It extends the medial four digits at the metacarpophalangeal joints
Explanation:Extensor digitorum is a long muscle located in the posterior compartment of the forearm. Together with the extensor carpi ulnaris and extensor digiti minimi, extensor carpi radialis longus and brevis as well as the brachioradialis, it belongs to the group of superficial extensors of the forearm. These muscles can be easily palpated in the lateral aspect of the posterior forearm, especially during the extension of hand when they are contracted.
Extensor digitorum runs from the lateral epicondyle of humerus to the medial four phalanges of the hand. In this way, it generates the pull for the extension of the four medial fingers in their metacarpophalangeal and both interphalangeal joints. Extensor digitorum also participates in the extension of the wrist.
Extensor digitorum is innervated by posterior interosseous nerve which is a continuation of a deep branch of radial nerve (root value C7 and C8).
Extensor digitorum is vascularized by the branches of three different arteries: (1) posterior interosseous artery, (2) radial recurrent artery, and (3) anterior interosseous artery. Anterior and posterior interosseous arteries are the branches of the common interosseous artery that arises from the ulnar artery. The radial recurrent artery is a branch of the radial artery.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 59
Correct
-
Hartmann's solution contains how much sodium:
Your Answer: 131 mmol/L
Explanation:Hartmann’s solution (compound sodium lactate) contains: Na+131 mmol/L, K+5 mmol/L, HCO3-29 mmol/L (as lactate), Cl-111 mmol/L, Ca2+2 mmol/L. It can be used instead of isotonic sodium chloride solution during or after surgery, or in the initial management of the injured or wounded; it may reduce the risk of hyperchloraemic acidosis.
-
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
-
-
Question 60
Correct
-
In the treatment of bradyarrhythmias with adverse characteristics or risk of asystole, what is the initial suggested dose of atropine?
Your Answer: 500 micrograms
Explanation:Atropine 500 mcg IV bolus should be administered if there are any adverse features or risk of asystole. If the reaction is not adequate, repeat the steps every 3 to 5 minutes up to a maximum dose of 3 mg. In the case of acute myocardial ischemia or myocardial infarction, atropine should be taken with caution since the increased heart rate may aggravate the ischemia or increase the size of the infarct.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 61
Incorrect
-
A 39-year-old guy comes to the emergency room with a persistent nasal bleed. You suspect the bleeding is coming from Little's area based on your examination. Which of the blood vessels listed below is most likely to be involved:
Your Answer:
Correct Answer: Sphenopalatine and superior labial arteries
Explanation:The Kiesselbach plexus is a vascular network formed by five arteries that supply oxygenated blood to the nasal septum, which refers to the wall separating the right and left sides of the nose. The five arteries that form the Kiesselbach plexus: the sphenopalatine artery, which branches from the maxillary artery originating behind the jawbone; the anterior ethmoidal artery, which branches from the ophthalmic artery behind the eye; the posterior ethmoidal artery, which also branches from the ophthalmic artery; the septal branch of the superior labial artery, which is a branch of the facial artery supplying blood to all of the superficial features of the face; and finally, the greater palatine artery, which is a terminal branch of the maxillary artery.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 62
Incorrect
-
You are reviewing a patient following a fall from a horse. You suspect they may have an Erb's palsy as a result of a brachial plexus injury. Regarding Erb's palsy, which one of the following statements is CORRECT:
Your Answer:
Correct Answer: Erb's palsy may result in loss of sensation of the regimental badge area.
Explanation:Erb’s palsy is caused by damage to the C5 and C6 nerve roots and thus primarily involves the musculocutaneous, suprascapular and axillary nerves. It commonly result from an excessive increase in the angle between the neck and the shoulder e.g. a person thrown from a motorbike or horseback or during a difficult birth. There is loss or weakness of abduction, lateral rotation and flexion of the arm and flexion and supination of the forearm and loss of sensation on the lateral arm. A characteristic ‘Waiter’s tip’ deformity may be present where the limb hangs limply by the side, medially rotated by the unopposed action of pectoralis major with the forearm pronated due to paralysis of the biceps brachii.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 63
Incorrect
-
Which of the following is an example of continuous data:
Your Answer:
Correct Answer: Height
Explanation:Continuous data is data where there is no limitation on the numerical value that the variable can take e.g. weight, height.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 64
Incorrect
-
The primary mechanism of action of ketamine is:
Your Answer:
Correct Answer: N-methyl-D-aspartate (NMDA)-receptor antagonist
Explanation:Ketamine is a non-competitive antagonist of the calcium-ion channel in the NMDA (N-methyl-D-aspartate) receptor. It further inhibits the NMDA-receptor by binding to its phencyclidine binding site. Ketamine also acts at other receptors as an opioid receptor agonist (analgesic effects), as an muscarinic anticholinergic receptor antagonist (antimuscarinic effects) and by blocking fast sodium channels (local anaesthetic effect).
Overdose may lead to panic attacks and aggressive behaviour; rarely seizures, increased ICP, and cardiac arrest
Very similar in chemical makeup to PCP (phencyclidine), but it is shorter acting and less toxic
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 65
Incorrect
-
One of your patients has been infected by an obligate pathogen and presents with features of this condition.
Which of these is an example of an obligate pathogen?
Your Answer:
Correct Answer: Trepenoma pallidum
Explanation:Treponema pallidum is an obligate pathogen. Obligate pathogens are almost always associated with disease and usually cannot survive outside of the body for long periods of time. Examples include and HIV.
Staphylococcus aureus and Bacteroides fragilis are conditional pathogens. These are pathogens that usually cause disease only if certain conditions are met.
Pneumocystis jiroveci and Pseudomonas aeruginosa, are opportunistic pathogens. These are pathogens that can only cause disease in an immunocompromised host or under unusual circumstances.
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 66
Incorrect
-
Regarding the phases of gastric secretion, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A high pH in the stomach inhibits gastrin secretion.
Explanation:A low pH in the stomach inhibits gastrin secretion, therefore when the stomach is empty or when acid has been secreted for some time after food has entered it, there is inhibition of acid secretion. However, when food first enters the stomach, the pH rises, and this leads to release of the inhibition and causes a maximum secretion of gastrin. Thus gastric acid secretion is self-regulating.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 67
Incorrect
-
All of the following statements are correct with regards to protection of the gastric mucosa except which of the following?
Your Answer:
Correct Answer: NSAIDs directly stimulate increased parietal cell acid production.
Explanation:Prostaglandin production, which usually inhibits acid secretion and increases mucus and bicarbonate secretion, is inhibited by NSAIDs.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 68
Incorrect
-
Which of the following clotting factors is NOT vitamin K-dependent:
Your Answer:
Correct Answer: V
Explanation:Fat-soluble vitamin K is obtained from green vegetables and bacterial synthesis in the gut. Deficiency may present in the newborn (haemorrhagic disease of the newborn) or in later life. Deficiency may be caused by an inadequate diet, malabsorption or inhibition of vitamin K by drugs such as warfarin. The activity of factors II, VII, IX and X are vitamin K dependent as well as that of protein C and protein S. Both PT and APTT are prolonged.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 69
Incorrect
-
Streptococcus viridans has developed subacute bacterial endocarditis in your patient. Which of the following locations is most likely to be the organism's origin?
Your Answer:
Correct Answer: Oral cavity
Explanation:Streptococci that are alpha-haemolytic, such as Streptococcus viridans, are major components of the flora in the oral cavity.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 70
Incorrect
-
Mast cells play a significant part in which of the following?
Your Answer:
Correct Answer: Allergic disease
Explanation:Mast cells play a central role in the response to allergen challenges. The activation of mast cells results in both an early and a delayed phase of inflammation. Mast cells have been implicated in both physiologic and pathogenic processes. Mast cells are important in defence against some bacteria and viruses and contribute to defence against parasites. They are key effector cells in both innate and acquired immunity and are capable of inducing and amplifying both types of responses. Specifically, mast cells are capable of detecting microbial products through surface pattern recognition receptors, and they are involved in the recruitment of other leukocytes, containment of bacterial infections, and tissue repair.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 71
Incorrect
-
Which of the following statements about sickle cell disease is TRUE:
Your Answer:
Correct Answer: Hand-foot syndrome is frequently a first presentation of the disease.
Explanation:Hand-foot syndrome in children is typically the first symptom of the disease, produced by infarction of the metaphysis of small bones. The disease is inherited as an autosomal recessive trait. By adulthood, the spleen has usually infarcted. Infection with the B19 parvovirus is usually followed by an aplastic crisis. Thrombocytopenia is caused by splenic sequestration.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 72
Incorrect
-
A 6-year-old girl is brought into the paediatric emergency room by her mother in a state of high-grade fever and extreme irritability. She is also reluctant to urinate as it is associated with lower abdominal pain and stinging. She has no history of any UTIs requiring antibiotics in the past 12 months.
The urine sensitivity test report is still unavailable. A clean catch urine sample is taken for urine dipstick, which reveals the presence of blood, protein, leukocytes and nitrites. Fresh blood tests were sent, and her estimated GFR is calculated to be 40 ml/minute.
Out of the following, which antibiotic is most appropriate to be prescribed to this patient?Your Answer:
Correct Answer: Trimethoprim
Explanation:The NICE guidelines for children and young people under 16 years lower UTIs are:
1. Get a urine sample before antibiotics are taken, and do a dipstick test OR send for culture and susceptibility
2. Assess and manage children under 5 with lower UTI with fever as recommended in the NICE guideline on fever in under 5s.
3. Prescribe an immediate antibiotic prescription and take into account the previous urine culture and susceptibility results, previous antibiotic use, which may have led to resistant bacteria
4. If urine culture and susceptibility report is sent
– Review the choice of antibiotic when the results are available AND
– change the antibiotic according to susceptibility results if the bacteria are resistant and symptoms are not improving, using a narrow-spectrum antibiotic wherever possibleThe choice of antibiotics for non-pregnant young people under 16 years with lower UTI is summarised below:
1. Children under 3 months:
– Refer to paediatric specialist and treat with intravenous antibiotic in line with NICE guideline on fever in under 5s
2. Children over 3 months:
– First-choice
Nitrofurantoin – if eGFR >45 ml/minute
Trimethoprim – (if low risk of resistance*)
– Second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice not suitable)
Nitrofurantoin – if eGFR >45 ml/minute and not used as first-choice
Amoxicillin (only if culture results available and susceptible)
Cefalexin -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 73
Incorrect
-
A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.
Cushing's syndrome is most commonly caused by which of the following?Your Answer:
Correct Answer: Iatrogenic administration of corticosteroids
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.
Cushing’s syndrome has several endogenous sources, including:
Cushing’s disease is caused by a pituitary adenoma.
Adrenal adenoma Ectopic corticotropin syndrome, e.g. small cell cancer of the lung
Adrenal carcinoma is a cancer of the adrenal gland.
Hyperplasia of the adrenal glands -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 74
Incorrect
-
A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.
Which of these anatomic structures is the deepest structure injured in the case above?Your Answer:
Correct Answer: Transversalis fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:
Skin
Fatty layer of the superficial fascia (Camper’s fascia)
Membranous layer of the superficial fascia (Scarpa’s fascia)
Aponeurosis of the external and internal oblique muscles
Rectus abdominis muscle
Aponeurosis of the internal oblique and transversus abdominis
Fascia transversalis
Extraperitoneal fat
Parietal peritoneum -
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 75
Incorrect
-
Which of these drugs may reduce the efficacy of contraception?
Your Answer:
Correct Answer: Carbamazepine
Explanation:Antiepileptic medications such as carbamazepine (Tegretol), topiramate (Topamax), and phenytoin (Dilantin) are widely known for reducing the contraceptive effectiveness of OCPs.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 76
Incorrect
-
Regarding the trachea, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A cricothyrotomy involves making an opening in the neck inferior to the cricoid cartilage.
Explanation:A cricothyrotomy involves making an opening in the median cricothyroid ligament (the medial part of the cricothyroid membrane), between the cricoid cartilage below and the thyroid cartilage above.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 77
Incorrect
-
A 45-year-old obese patient goes to the emergency department with a fever and significant right upper quadrant pain. The pain radiates to her right shoulder tip. Murphy's sign is positive and acute cholecystitis is diagnosed. The pain referred to the shoulder tip is caused by one of the following nerves:
Your Answer:
Correct Answer: Phrenic nerve
Explanation:Gallbladder inflammation can cause pain in the right upper quadrant and right shoulder, which is caused by irritation of the diaphragmatic peritoneum. Pain from areas supplied by the phrenic nerve is often referred to other somatic regions served by spinal nerves C3-C5.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 78
Incorrect
-
On which of the following types of receptors does loperamide act?
Your Answer:
Correct Answer: Opioid receptors
Explanation:Loperamide inhibits acetylcholine release from the myenteric plexus acts by action on opioid mu-receptors, and this then reduces bowel motility. The intestinal transit time is increased, thereby facilitating water reabsorption.
-
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
-
-
Question 79
Incorrect
-
A patient is complaining of painless jaundice. His bilirubin levels are abnormally high.
Which of the following statements about bile is correct?Your Answer:
Correct Answer: Bile acids are amphipathic
Explanation:The liver produces bile on a constant basis, which is then stored and concentrated in the gallbladder. In a 24-hour period, around 400 to 800 mL of bile is generated.
Bile is involved in the following processes:
Fats are broken down into fatty acids.
Waste products are eliminated.
Cholesterol homeostasis is the balance of cholesterol in the body.The enteric hormones cholecystokinin and secretin are primarily responsible for bile secretion. When chyme from an unprocessed meal enters the small intestine, they are released, and they play the following function in bile secretion and flow:
Cholecystokinin promotes gallbladder and common bile duct contractions, allowing bile to reach the intestine.
Secretin enhances the secretion of bicarbonate and water by biliary duct cells, increasing the amount of bile and its flow into the gut.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:
Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.
Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 80
Incorrect
-
A 39-year-old woman's son with meningococcal meningitis was recently admitted to the Paediatric Intensive Care Unit. She is currently 22 weeks pregnant and is concerned about the possibility of her also contracting the disease as she cared closely for her son during his admission.
Which antibiotic would be the MOST appropriate choice for chemoprophylaxis in this case?
Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin is recommended for use as meningococcal chemoprophylaxis in all age groups and in pregnancy, and is the most appropriate for this patient.
However, rifampicin is the drug of choice for meningococcal chemoprophylaxis because it is licensed for chemoprophylaxis, but multiple doses are necessary and it is not readily available in community pharmacies. It also interacts with oral contraceptives.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 81
Incorrect
-
Damage to this nerve affects the flexor digitorum longus.
Your Answer:
Correct Answer: Tibial nerve
Explanation:Like all muscles in the deep posterior compartment of the leg, flexor digitorum longus muscle is innervated by branches of the tibial nerve (root value L5, S1 and S2) which is a branch of sciatic nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 82
Incorrect
-
Which of the following nerves innervates the adductor brevis?
Your Answer:
Correct Answer: Obturator nerve
Explanation:Like the majority of the thigh adductors, adductor brevis is innervated by the obturator nerve. Obturator nerve is derived from the lumbar plexus (anterior branches of spinal nerves L2-L4).
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 83
Incorrect
-
A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.
Which of the following biochemical profiles best supports this diagnosis?Your Answer:
Correct Answer: Hypokalaemic metabolic alkalosis
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.
A typical biochemical profile can help establish a diagnosis of Cushing’s syndrome. The following are the primary characteristics:
Hypokalaemia
Alkalosis metabolique -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 84
Incorrect
-
When treating diabetic ketoacidosis (DKA), glucose should be given together with insulin as soon as the blood glucose concentration falls below 14 mmol/L in the form of:
Your Answer:
Correct Answer: 10% glucose intravenous infusion at a rate of 125 mL/hour
Explanation:In addition to the sodium chloride 0.9 percent infusion, glucose 10% should be given intravenously (into a large vein with a large-gauge needle) at a rate of 125 mL/hour once blood glucose concentration falls below 14 mmol/litre.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 85
Incorrect
-
A 30-year-old woman presents with a history of fever and sore throat. On examination, there is tonsillar exudate and cervical lymphadenopathy and a diagnosis of tonsillitis is made. A course of penicillin is prescribed.
What is the mechanism of action of penicillin?
Your Answer:
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillin is bactericidal and produces its antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. This action inhibits cell wall synthesis.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 86
Incorrect
-
The following statements about leukotrienes as chemical mediators of the acute inflammatory response are all true EXCEPT?
Your Answer:
Correct Answer: They decrease vascular permeability
Explanation:Leukotrienes increases (not decrease) vascular permeability during acute inflammation.
All the other statements are correct
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 87
Incorrect
-
Fat necrosis is typically seen in which of the following:
Your Answer:
Correct Answer: Acute pancreatitis
Explanation:Fat necrosis typically occurs following either direct trauma or from enzymatic lipolysis in acute pancreatitis, where release of triglyceride elicits a rapid inflammatory response and fat is phagocytosed by neutrophils and macrophages with subsequent fibrosis.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 88
Incorrect
-
Angiotensin II acts to cause all but which one of the following effects:
Your Answer:
Correct Answer: Inhibit release of ADH from the posterior pituitary gland
Explanation:Angiotensin II acts to:
Stimulate release of aldosterone from the zona glomerulosa of the adrenal cortex (which in turn acts to increase sodium reabsorption)
Cause systemic vasoconstriction
Cause vasoconstriction of the renal arterioles (predominant efferent effect thus intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR)
Directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters)
Stimulate synthesis and release of ADH from the hypothalamus and posterior pituitary respectively
Stimulate the sensation of thirst
Potentiate sympathetic activity (positive feedback)
Inhibit renin production by granular cells (negative feedback) -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 89
Incorrect
-
Regarding an avulsion fracture, a sudden contraction of which muscle may lead to fracture of the head of the fibula?
Your Answer:
Correct Answer: Biceps femoris
Explanation:Avulsion fractures of the fibular head are rare and are so-called the arcuate signal. The “arcuate signal” is used to describe an avulsed bone fragment related to the insertion site of the tendon of the biceps femoris associated with the arcuate complex, which consists of the fabellofibular, popliteofibular, and arcuate ligaments. Such lesions are typically observed in direct trauma to the knee with excessive varus and internal rotation forces or indirect trauma with the same direction of the force.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 90
Incorrect
-
A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.
Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?Your Answer:
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 91
Incorrect
-
A 45-year-old African American male presents to your clinic complaining of swelling of his feet for the past six months. On examination, there is periorbital and pedal oedema. A 24-hour urine collection is ordered, which shows 8 g of protein. The serum cholesterol is ten mmol/L. You order a renal biopsy to confirm the diagnosis.
Which one of the following findings are you most likely to see in this patient's biopsy?Your Answer:
Correct Answer: Focal segmental glomerulosclerosis
Explanation:This patient has Nephrotic Syndrome confirmed by the presence of 1. Heavy proteinuria (greater than 3-3.5 g/24 hours)
2. Hypoalbuminemia (serum albumin < 25 g/L)
3. Generalised oedema (often with periorbital involvement)
4. Severe hyperlipidaemia (total cholesterol is often > 10 mmol/L).Focal Segmental Glomerulosclerosis will be the most likely answer as it is the most common cause of Nephrotic Syndrome in African American adults.
Minimal change disease is the most common cause of nephrotic syndrome in children.
Membranous glomerulonephritis is the most common cause of Nephrotic Syndrome in Caucasian adults.
In IgA nephropathy, patients will complain of cola-coloured urine.
Mesangiocapillary glomerulonephritis presents with features of Nephritic Syndrome.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 92
Incorrect
-
Regarding macrolide antibiotics, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Macrolides are first line for treatment of whooping cough.
Explanation:A macrolide antibiotic is recommended first line for whooping cough (if onset of cough is within the previous 21 days)
Prescribe clarithromycin for infants less than 1 month of age.
Prescribe azithromycin or clarithromycin for children aged 1 month or older, and non-pregnant adults.
Prescribe erythromycin for pregnant women.
Macrolides interfere with bacterial protein synthesis and are mainly active against Gram-positive organisms. They have a similar antibacterial spectrum to penicillin and are thus a useful alternative in penicillin-allergic patients. Erythromycin is commonly associated with gastrointestinal upset. -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 93
Incorrect
-
Intrinsic factor is vital for gastrointestinal absorption of which of the following:
Your Answer:
Correct Answer: Vitamin B12
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 94
Incorrect
-
A 56-year-old man presents with pneumonia 8 days after being admitted for an open fracture of his tibia and fibula. Upon history taking and observation, it was established that he has no known drug allergies, has coarse left basal crackles and evidence of consolidation in the left lower lobe based on his chest X-ray.
Which of the following antibacterial agents would be the most appropriate to prescribe according to the latest NICE guidelines?Your Answer:
Correct Answer: Ciprofloxacin
Explanation:The current NICE guidelines for hospital-acquired pneumonia are as follow:
– First-choice oral antibiotic if non‑severe symptoms or signs, and not at higher risk of resistance (guided by microbiological results when available): co-amoxiclav– Alternative oral antibiotics if non‑severe symptoms or signs, and not at higher risk of resistance, for penicillin allergy or if co‑amoxiclav unsuitable (based on specialist microbiological advice and local resistance data): doxycycline, cefalexin, co-trimoxazole, levofloxacin
– First-choice intravenous antibiotics if severe symptoms or signs (for example, symptoms or signs of sepsis) or at higher risk of resistance (based on specialist microbiological advice and local resistance data): piperacillin with tazobactam, ceftazidime, ceftriaxone, cefuroxime, meropenem, ceftazidime with avibactam, levofloxacin
– Antibiotics to be added if suspected or confirmed methicillin-resistant Staphylococcus aureus infection (dual therapy with a first-choice intravenous antibiotic): vancomycin, teicoplanin, linezolid
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 95
Incorrect
-
Funnel plots are typically used to display:
Your Answer:
Correct Answer: The existence of publication bias in meta-analysis
Explanation:Funnel plots are used to demonstrate the existence of publication bias in meta-analysis. Funnel plots are scatter plots of treatment effects estimated from individual studies on the x axis and some measure of study size on the y axis. Each point on the graph represents one of the studies. A symmetrical inverted funnel shape indicates an absence of publication bias. If there is publication bias, there will be asymmetry of the open wide end due to the absence of small negative results.
-
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
-
-
Question 96
Incorrect
-
A 70-year-old man has severe diarrhoea one week after taking co-amoxiclav for a chest infection. The diarrhoea is yellow in colour and smell is offensive.
What is the SINGLE MOST likely causative organism?
Your Answer:
Correct Answer: Clostridium difficile
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.
About 80% of Clostridium difficile infections are seen in people over the age of 65 and its main clinical features are:
Abdominal cramps, severe bloody and/or watery diarrhoea, offensive smelling diarrhoea, and fever. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 97
Incorrect
-
Which of the following acts to inhibit antidiuretic hormone (ADH) release from the posterior pituitary:
Your Answer:
Correct Answer: Atrial natriuretic peptide
Explanation:ADH release is inhibited by low plasma osmolality, alcohol, caffeine, glucocorticoids and atrial natriuretic peptide (ANP).
ADH release is stimulated primarily by raised plasma osmolality detected by osmoreceptors in the anterior hypothalamus. Other factors that increase ADH release include: extracellular fluid volume depletion, angiotensin II, nausea, pain, stress, exercise, emotion, hypoglycaemia.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 98
Incorrect
-
A 37-year-old man presents with breathlessness on exertion and dry cough, fever for the past 2 days and bilateral pleuritic chest pain.
He had been diagnosed with HIV and commenced on HAART but due to side effects, his compliance has been poor over the last few months.
On examination you note scattered crackles and wheeze bilaterally, cervical and inguinal lymphadenopathy, and oral thrush. At rest his oxygen saturation is 97% but this drops to 87% on walking. There is perihilar fluffy shadowing seen on his chest X-ray.
Which of these organisms is the most likely causative organism?
Your Answer:
Correct Answer: Pneumocystis jirovecii
Explanation:All of the organisms listed above can cause pneumonia in immunocompromised individuals but the most likely cause in this patient is Pneumocystis jirovecii.
It is a leading AIDS-defining infection in HIV-infected individuals and causes opportunistic infection in immunocompromised individuals. HIV patients with a CD4 count less than 200 cells/mm3 are more prone.
The clinical features of pneumonia caused by Pneumocystis jirovecii are:
Fever, chest pain, cough (usually non-productive), exertional dyspnoea, tachypnoea, crackles and wheeze.
Desaturation on exertion is a very sensitive sign of Pneumocystis jirovecii pneumonia.Chest X-ray can show perihilar fluffy shadowing (as is seen in this case) but can also be normal.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 99
Incorrect
-
Pressure across the wall of a flexible tube (the transmural pressure) increases wall tension and extends it.
Which law best describes transmural pressure?
Your Answer:
Correct Answer: Laplace’s law
Explanation:The transmural pressure (pressure across the wall of a flexible tube) can be described by Laplace’s law which states that:
Transmural pressure = (Tw) / r
Where:
T = Wall tension
w = Wall thickness
r = The radius
A small bubble with the same wall tension as a larger bubble will contain higher pressure and will collapse into the larger bubble if the two meet and join.Fick’s law describes the rate of diffusion in a solution
Poiseuille’s law is used to calculate volume of flow rate in laminar flow
Darcy’s law describes the flow of a fluid through a porous medium.
Starling’s law describes cardiac haemodynamics as it relates to myocyte contractility and stretch.
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 100
Incorrect
-
Regarding local anaesthetics, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Adrenaline should be used in digital nerve blocks to create a bloodless field.
Explanation:It is not advisable to give adrenaline/epinephrine with a local anaesthetic injection in digits or appendages because of the risk of ischaemic necrosis.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 101
Incorrect
-
Arterial baroreceptors are located primarily in which of the following:
Your Answer:
Correct Answer: Carotid sinus and aortic arch
Explanation:Arterial baroreceptors are located in the carotid sinus and aortic arch, and detect the mean arterial pressure (MAP). A decrease in MAP (such as in postural hypotension, or haemorrhage) reduces arterial stretch and decreases baroreceptor activity, resulting in decreased firing in afferent nerves travelling via the glossopharyngeal nerve (carotid sinus) and vagus nerve (aortic arch) to the medulla where the activity of the autonomic nervous system is coordinated. Sympathetic nerve activity consequently increases, causing an increase in heart rate and cardiac contractility, peripheral vasoconstriction with an increase in TPR, and venoconstriction with an increase in CVP and thus an increase in cardiac output and blood pressure. Parasympathetic activity (vagal tone) decreases, contributing to the rise in heart rate.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 102
Incorrect
-
Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 103
Incorrect
-
Which of the following drugs is first line treatment for a stable regular broad-complex tachycardia:
Your Answer:
Correct Answer: Amiodarone
Explanation:A regular broad-complex tachycardia is likely to be ventricular tachycardia or a regular supraventricular rhythm with bundle branch block. A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours. If previously confirmed as SVT with bundle branch block, the patient should be treated as for narrow-complex tachycardia.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 104
Incorrect
-
The fluid in contact with a tube is dragged by frictional forces to the tube's sidewalls. This creates a velocity gradient in which the fluid flow is greatest in the tube's centre.
Which of the following terms most accurately characterizes this flow pattern?Your Answer:
Correct Answer: Laminar flow
Explanation:The fluid in contact with a tube is dragged by frictional forces at the tube’s sidewalls. This creates a velocity gradient in which the fluid flow is greatest in the tube’s centre.
This is known as laminar flow, and it characterizes the flow in most circulatory and respiratory systems when they are at rest.The velocity of the fluid flow can fluctuate erratically at high velocities, particularly within big arteries and airways, disrupting laminar flow. As a result, resistance increases significantly.
This is known as turbulent flow, and symptoms include heart murmurs and asthmatic wheeze. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 105
Incorrect
-
Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.
Which enzyme hydroxylates 25-hydroxycholecalciferol to form 1,25-dihydroxycholecalciferol?Your Answer:
Correct Answer: 1-alpha-hydroxylase
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.
In the presence of UVB light, 7-dehydrocholesterol is converted to cholecalciferol in the epidermal layer of the skin, resulting in 1,25-dihydroxycholecalciferol.
Cholecalciferol is then converted to 25-hydroxycholecalciferol in the endoplasmic reticulum of liver hepatocytes by 25-hydroxylase (calcifediol).
Finally, 1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney. The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is induced by parathyroid hormone or hypophosphatemia.
The following are the primary effects of 1,25-dihydroxycholecalciferol:
Calcium and phosphate absorption in the small intestine is increased.
Calcium reabsorption in the kidneys is increased.
Increases phosphate reabsorption in the kidneys.
Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)
Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 106
Incorrect
-
Which of the following is NOT a side effect of phenytoin:
Your Answer:
Correct Answer: Ototoxicity
Explanation:Adverse effects of phenytoin include:
Nausea and vomiting
Drowsiness, lethargy, and loss of concentration
Headache, dizziness, tremor, nystagmus and ataxia
Gum enlargement or overgrowth
Coarsening of facial features, acne and hirsutism
Skin rashes
Blood disorders -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 107
Incorrect
-
Streptococcus pneumoniae is commonly implicated in all of the following infectious diseases EXCEPT for:
Your Answer:
Correct Answer: Impetigo
Explanation:Impetigo is a highly contagious infection of the superficial epidermis that most commonly affects young children but can occur in any age group. In children it is the most common bacterial skin infection and it is the third most common skin disease overall, behind dermatitis and viral warts.
The commonest causative organism is Staphylococcus aureus. Streptococcus pyogenesis the second commonest and causes fewer cases, either alone or in combination withS. aureus.The streptococcal form tends to be commoner in warmer, more humid climates. (Hirschmann JV. Impetigo: etiology and therapy. Curr Clin Top Infect Dis. 2002;22:42–51.)
Impetigo is most commonly spread by direct person-to-person contact, and can spread rapidly through families and school classes. It can also, less commonly, be spread by indirect contact.
There are two main forms of impetigo:
Non-bullous impetigo – lesions usually start as tiny pustules or vesicles that evolve rapidly into honey-crusted plaques that tend to be under 2 cm in diameter. These can be itchy but are rarely painful.
Bullous impetigo – lesions have a thin roof and tend to rupture spontaneously. This type is more likely to be painful and may be associated with systemic upset. -
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 108
Incorrect
-
Which of the following is NOT a typical cerebellar sign:
Your Answer:
Correct Answer: Hypertonia
Explanation:Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia, or it can be indicative of another problem where there is progressive loss of muscle tone, such as muscular dystrophy or cerebral palsy. It is usually detected during infancy. Hypotonia is characteristic of cerebellar dysfunction.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 109
Incorrect
-
Which of the following statements is correct regarding hyponatraemia?
Your Answer:
Correct Answer: Correction of serum sodium that is too rapid can precipitate central pontine myelinolysis.
Explanation:Hyponatraemia refers to a serum sodium concentration < 135 mmol/L.
It is safer to quickly correct acute hyponatremia than chronic hyponatremia but correction should not be too fast, especially in chronic hyponatraemia, because of the risk of central pontine myelinolysis. Hyponatraemia is usually associated with a low plasma osmolality.
Under normal circumstances, if serum osmolality is low, then urine osmolality should also be low because the kidneys should be trying to retain solute.
In SIADH, excess ADH causes water retention, but not the retention of solute. Therefore, urine that is concentrated and relatively high in sodium is produced, even though the serum sodium is low (urine osmolality > 100 mosmol/kg). -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 110
Incorrect
-
Question 111
Incorrect
-
For which of the following class of drugs can neostigmine be used as a reversal agent?
Your Answer:
Correct Answer: Non-depolarising muscle relaxants
Explanation:Neostigmine is used specifically for reversal of nondepolarizing (competitive) blockade and is anticholinesterase. It acts within one minute of intravenous injection, and the effects last for 20 to 30 minutes. After this time period, a second dose may then be necessary.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 112
Incorrect
-
Which of these is NOT a naturally occurring anticoagulant:
Your Answer:
Correct Answer: Factor V Leiden
Explanation:It’s crucial that thrombin’s impact is restricted to the injured site. Tissue factor pathway inhibitor (TFPI), which is produced by endothelial cells and found in plasma and platelets, is the first inhibitor to function. It accumulates near the site of harm induced by local platelet activation. Xa and VIIa, as well as tissue factor, are inhibited by TFPI. Other circulating inhibitors, the most potent of which is antithrombin, can also inactivate thrombin and other protease factors directly. Coagulation cofactors V and VIII are inhibited by protein C and protein S. Tissue plasminogen activator (TPA) from endothelial cells facilitates fibrinolysis by promoting the conversion of plasminogen to plasmin.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 113
Incorrect
-
Which of the following accurately describes the extensor pollicis brevis muscle?
Your Answer:
Correct Answer: It lies on the medial side of abductor pollicis longus
Explanation:Extensor pollicis brevis is a short and slender muscle located in the posterior compartment of the forearm, extending from the posterior surface of radius to the proximal phalanx of thumb. It is one of the deep extensors of the forearm, together with supinator, abductor pollicis longus, extensor pollicis longus and extensor indicis muscles.
Extensor pollicis brevis is a deep extensor of the thumb that lies deep to extensor digitorum muscle. It sits directly medial to abductor pollicis longus and posterolateral to extensor pollicis longus muscle. Just above the wrist, extensor pollicis brevis obliquely crosses the tendons of extensor carpi radialis brevis and extensor carpi radialis longus muscles.
Extensor pollicis brevis is innervated by posterior interosseous nerve which is a continuation of a deep branch of radial nerve (root value C7 and C8).
Extensor pollicis brevis receives its blood supply by posterior interosseous artery and perforating branches from the anterior interosseous artery, which are the branches of common interosseous artery. The common interosseous artery arises immediately below the tuberosity of radius from the ulnar artery.
Together with extensor pollicis longus, extensor pollicis brevis is in charge of extension of the thumb in the first metacarpophalangeal joint. It also extends the thumb in the carpometacarpal joint of the thumb. This movement is important in the anatomy of the grip, as it enables letting go of an object. As it crosses the wrist, extensor pollicis brevis also participates in the extension and abduction of this joint.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 114
Incorrect
-
Naloxone is a reversal agent for which of the following groups of drugs:
Your Answer:
Correct Answer: Opioids
Explanation:Naloxone is a specific antagonist of mu(μ)-opioid receptors, the specific antidote for opioid overdose and will reverse respiratory depression and coma if given at sufficient dosage. The initial dose is usually 0.8 mg (2 mL) intravenously (the dose range suggested by BNF is 0.4-2 mg). It can also be given by intramuscular injection if the intravenous route is not feasible.
As naloxone has a shorter duration of action than most opioids, close monitoring and repeated injections are necessary according to the respiratory rate and depth of coma. The dose is generally repeated every 2-3 minutes to a maximum of 10 mg. When repeated doses are needed, naloxone may be given by a continuous infusion adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
In opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 115
Incorrect
-
A 27-year-old man was sent to the emergency department by ambulance with suspected anaphylaxis. What is the best first-line treatment for this patient?
Your Answer:
Correct Answer: 500 micrograms of adrenaline intramuscularly
Explanation:Anaphylaxis is the sudden onset of systemic hypersensitivity due to IgE-mediated chemical release from mast cells and basophils.
If anaphylaxis is suspected, 500 micrograms of adrenaline should be administered promptly (0.5 ml of 1:1000 solution).
In anaphylaxis, the intramuscular route is the most immediate approach; the optimal site is the anterolateral aspect of the middle part of the thigh.
Intravenous adrenaline should only be given by people who are well-versed in the use and titration of vasopressors in their routine clinical practice.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 116
Incorrect
-
Through which of the following anatomical structures does an indirect inguinal hernia pass?
Your Answer:
Correct Answer: External oblique
Explanation:Inguinal hernias are subdivided into direct and indirect.
An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum.
A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
The deep (internal) inguinal ring is located above and halfway between the pubic tubercle and the anterior superior iliac spine. This serves as the entrance to the inguinal canal. The superficial (external) inguinal ring lies immediately above and medial to the pubic tubercle. This triangular opening is a defect in the external oblique aponeurosis, and forms the exit of the inguinal canal.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 117
Incorrect
-
A patient has a cardiac output of 4.8 L/min and a heart rate of 80 bpm, therefore their stroke volume is:
Your Answer:
Correct Answer: 60 mL
Explanation:Cardiac output (CO) = Stroke volume (SV) x Heart rate (HR).
Therefore SV = CO/HR
= 4.8/80
= 0.06 L = 60 mL. -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 118
Incorrect
-
All of the following typically occurs as part of normal inspiration except:
Your Answer:
Correct Answer: Contraction of the internal intercostal muscles
Explanation:Passive inspiration is a result of contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs).
In inspiration, several movements occur. These are:
1. elevation of the sternal ends of the ribs (‘pump handle’ movement),
2. elevation of the lateral shafts of the ribs (‘bucket handle’ movement)
3. depression of the diaphragm.
These result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. There is an increased intrathoracic volume and decreased intrathoracic pressure and air is drawn into the lungs. -
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 119
Incorrect
-
A patient is referred for lung function tests on account of a history of breathlessness and cough.
Which statement about lung volumes is correct?
Your Answer:
Correct Answer: The tidal volume is the volume of air drawn in and out of the lungs during normal breathing
Explanation:The tidal volume(TV) is the amount of air that moves in and out of the lungs with each respiratory cycle. In a healthy male, the usual volume is 0.5 L (,7 ml/kg body mass).
The vital capacity(VC) is the maximum amount of air that can be exhaled following maximal inspiration. The usual volume in a healthy male is 4.5 L.
The residual volume(RV) is the amount of air remaining in the lungs after maximum expiration. The usual volume in a healthy male is 1.0 L.
The inspiratory reserve volume(IRV) is the maximum amount of air that can be breathed in forcibly after normal inspiration. The usual volume in a healthy male is 3.0 L.
The expiratory reserve volume(ERV) is the volume of air that can be breathed out forcibly after normal expiration. The usual volume in a healthy male is 1.0 L.
Total lung capacity(TLC) is the volume of air the lungs can accommodate. TLC = RV+VC. The usual volume in a healthy male is 5.5 L.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 120
Incorrect
-
Antispasmodic drugs are primarily indicated in which of the following conditions:
Your Answer:
Correct Answer: Irritable bowel syndrome
Explanation:Antispasmodics, such as antimuscarinics, may be used in the management of irritable bowel syndrome. Other antispasmodics used include direct-acting smooth muscle relaxants such as mebeverine, alverine, and peppermint oil. Antispasmodics are contraindicated in bowel obstruction and severe inflammatory bowel disease. Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects. Antimuscarinics are contraindicated in urinary retention.
-
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
-
-
Question 121
Incorrect
-
A 68-year-old female has presented to the Emergency Department with chest pain, palpitations, and breathlessness complaints. On ECG, she is diagnosed with ventricular arrhythmia and is administered lidocaine.
Which of the following is the correct mechanism of action of lidocaine?Your Answer:
Correct Answer: Blocks Na+ channels in the heart
Explanation:Lidocaine is a tertiary amide local anaesthetic and also a class IV antiarrhythmic.
Like other local anaesthetics, lidocaine works on the voltage-gated sodium ion channel on the nerve cell membranes. It works in the following steps:
1. diffuses through neural sheaths and the axonal membrane into the axoplasm
2. binds fast voltage-gated Na+ channels in the neuronal cell membrane and inactivates them
3. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signalsThe same principle applies to Lidocaine’s actions in the heart as it blocks the sodium channels in the conduction system and the myocardium. This raises the threshold for depolarizing, making it less likely for the heart to initiate or conduct any action potential that can cause arrhythmia.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 122
Incorrect
-
The blood test reports of a 56-year-old female are sent for your review. She seems acutely sick and has had multiple infections over the past few months. Her complete blood count report shows neutropenia.
Which one of the following options is true with regards to neutropenia?Your Answer:
Correct Answer: It can be caused by both radiotherapy and chemotherapy
Explanation:A total neutrophil count of less than 2 x 109/L is defined as neutropenia. It can be caused by the following:
1. viral infections
2. SLE
3. RA
4. hypersplenism
5. chemo- and radiotherapy
6. vitamin B12 and folate deficiency
7. drug reactions -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 123
Incorrect
-
A 17-year-old patient with a headache, fever, and a non-blanching rash is brought to the emergency room. Meningococcal infection is confirmed by a lumbar puncture. Neisseria meningitidis uses one of the following immune evasion mechanisms:
Your Answer:
Correct Answer: Secretes IgA protease
Explanation:Meningococci have 3 important virulence factors, as follows:
Polysaccharide capsule – Individuals with immunity against meningococcal infections have bactericidal antibodies against cell wall antigens and capsular polysaccharides; a deficiency of circulating anti meningococcal antibodies is associated with the disease.
Lipo-oligosaccharide endotoxin (LOS)
Immunoglobulin A1 (IgA1) -
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 124
Incorrect
-
Which of the following is true regarding respiration?
Your Answer:
Correct Answer: The diaphragm is responsible for abdominal breathing
Explanation:The following are the mechanisms of breathing during inspiration and expiration, whether normal or forced.
Normal inspiration is an active process, with the diaphragm as the main muscle. The diaphragm descends, ribs move upward and outward, and the lungs become wider and taller.
In forced inspiration, which commonly occurs during exercise, the external intercostals and accessory muscles, such as the sternocleidomastoid, anterior serrati, scalenes, alae nasi, genioglossus and arytenoid are involved. The ribs move upward and outward, and the abdominal contents move downward.
Normal expiration is a passive process, while in forced expiration, the internal intercostals and abdominal muscles, such as the rectus abdominis, internal and external obliques and transversus abdominis are involved. The ribs move downward and inward, and the abdominal contents move upward.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 125
Incorrect
-
Which of the following is the most common cause of megaloblastic anaemia:
Your Answer:
Correct Answer: Vitamin B12 deficiency
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.
Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time. -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 126
Incorrect
-
Which of the following is typically used in diabetes mellitus as the cut-off to define hypoglycaemia?
Your Answer:
Correct Answer: < 4.0 mmol/L
Explanation:Hypoglycaemia is defined as plasma glucose of less than 4 mmol/L.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 127
Incorrect
-
A 25-year-old patient requires procedural sedation for reduction of an open fracture of his tibia and fibula. You plan on using ketamine as the sedative agent.
Ketamine works as a result of action on what type of receptor? Select ONE answer only.Your Answer:
Correct Answer: N-methyl-D-aspartate (NMDA)
Explanation:Ketamine is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties. When used correctly it is a very useful and versatile drug.
Ketamine acts by non-competitive antagonism of the NMDA receptor Ca2+ channel pore and also inhibits NMDA receptor activity by interaction with the phencyclidine binding site.
Ketamine can be used intravenously and intramuscularly. The intramuscular dose is 10 mg/kg, and when used by this route, it acts within 2-8 minutes and has a duration of action of 10-20 minutes. The intravenous dose is 1.5-2 mg/kg administered over a period of 60 seconds. When used intravenously, it acts within 30 seconds and has a duration of action of 5-10 minutes. Ketamine is also effective when administered orally, rectally, and nasally.
Ketamine causes tachycardia, an increase in blood pressure, central venous pressure, and cardiac output, secondary to an increase in sympathetic tone. Baroreceptor function is well maintained, and arrhythmias are uncommon.
The main disadvantage to the use of ketamine is the high incidence of hallucinations, nightmares, and other transient psychotic effects. These can be reduced by the co-administration of a benzodiazepine, such as diazepam or midazolam.
The main side effects of ketamine are:
Nausea and vomiting
Hypertension
Nystagmus
Diplopia
Rash -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 128
Incorrect
-
All of the following typically occurs as part of normal passive expiration except:
Your Answer:
Correct Answer: Contraction of the internal intercostal muscles
Explanation:Passive expiration is produced primarily by relaxation of the inspiratory muscles (diaphragm and external intercostal muscles) in addition to the elastic recoil of the lungs.
In expiration, several movements occur. There are:
1. depression of the sternal ends of the ribs (‘pump handle’ movement),
2. depression of the lateral shafts of the ribs (‘bucket handle’ movement) and
3. elevation of the diaphragm.
These result in a reduction of the thorax in an anteroposterior, transverse and vertical direction respectively. There is then a decreased intrathoracic volume and increased intrathoracic pressure and air is forced out of the lungs. -
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 129
Incorrect
-
Atrial natriuretic peptide (ANP) acts to cause all of the following effects EXCEPT for:
Your Answer:
Correct Answer: Vasoconstricts the afferent arteriole
Explanation:ANP acts to:
Inhibit Na+ reabsorption in the distal nephron (through inhibition of ENaC in principal cells)
Suppress the production of renin
Suppress the production of aldosterone
Suppress the production of ADH
Cause renal vasodilation, increasing the glomerular filtration rate -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 130
Incorrect
-
Which of the following is considered the best source of information if a research on the national hospital MRSA rates is being done?
Your Answer:
Correct Answer: Hospital Episode Statistics
Explanation:Hospital Episode Statistics (HES) is a data warehouse containing details of all admissions, outpatient appointments and A and E attendances at NHS hospitals in England.
Each HES record contains a wide range of information about an individual patient admitted to an NHS hospital, including:
– clinical information about diagnoses and operations
– patient information, such as age group, gender and ethnicity
– administrative information, such as dates and methods of admission and discharge
– geographical information such as where patients are treated and the area where they liveSome benefits of HES include:
– monitor trends and patterns in NHS hospital activity
– assess effective delivery of care
– support local service planning
– reveal health trends over time
– determine fair access to health care -
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 131
Incorrect
-
Which of the following states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each of the gases in the mixture:
Your Answer:
Correct Answer: Dalton's law
Explanation:Dalton’s law states that when two or more gases, which do not react chemically, are present in the same container, the total pressure is the sum of the partial pressures of each gas.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 132
Incorrect
-
An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:
No. of patients who took Ticagrelor: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the absolute risk reduction of a stroke, with Warfarin as the standard of treatment.Your Answer:
Correct Answer: -0.06
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).
Since Warfarin is the standard of treatment, Warfarin is considered as the control group.
ARR = ARC-ART
ARR = (20/500) – (30/300)
ARR = -0.06This means that there is increased risk of stroke in the treatment group, which is the Ticagrelor group.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 133
Incorrect
-
A 21-year-old student presents to the minors area of your Emergency Department with a laceration on his external nose that occurred during sparring in a kickboxing class. The area is bleeding profusely and will require suturing. Pressure is being applied. The laceration extends through some of the nasal muscles.
Motor innervation of the nasal muscles of facial expression is provided by which of the following ? Select ONE answer only.Your Answer:
Correct Answer: Facial nerve
Explanation:The facial nerve (the labyrinthine segment) is the seventh cranial nerve, or simply CN VII. It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
Motor innervation of the nasal muscles of facial expression is provided by the facial nerve (CN VII). -
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 134
Incorrect
-
A 35-year-old man is feeling unwell following his return from a business trip. He is diagnosed with a vector transmitted disease.
Which of these organisms is commonly spread by vector-borne transmission?Your Answer:
Correct Answer: Borrelia burgdorferi
Explanation:Borrelia burgdorferiis, primarily spread by ticks and lice, is a zoonotic, vector-borne organism that causes Lyme disease.
Neisseria meningitidis and Bordetella pertussis are droplet borne infections (airborne particle > 5 µm)
Vibrio cholerae and Ascaris lumbricoides are spread by the faeco-oral route
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 135
Incorrect
-
Amoxicillin is used first line for all of the following infections EXCEPT for:
Your Answer:
Correct Answer: Cellulitis
Explanation:Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI). Flucloxacillin is used first line for acute cellulitis.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 136
Incorrect
-
A 26-year old female comes to the Emergency Room with complaints of bloody stools. She reports that prior to the passage of bloody stools, she experienced a sharp pain during defecation. Medical history reveals that she has been experiencing constipation for the past 2 weeks. After completing her medical history and physical examination, the attending physician gives an initial diagnosis of an anal fissure.
Which of the following nerves transmit painful sensation from the anus, resulting in the pain associated with anal fissure?Your Answer:
Correct Answer: Inferior rectal nerve
Explanation:A fissure in ano is a tear in the anoderm distal to the dentate line. The pathophysiology of anal fissure is thought to be related to trauma from either the passage of hard stool or prolonged diarrhoea. A tear in the anoderm causes spasm of the internal anal sphincter, which results in pain, increased tearing, and decreased blood supply to the anoderm. The site of the anal fissure in the sensitive lower half of the anal canal, which is innervated by the inferior rectal nerve, results in reflex spasm of the external anal sphincter, aggravating the condition. Because of the intense pain, anal fissures may have to be examined under local anaesthesia.
The inferior rectal nerve is a branch of the pudendal nerve. This nerve runs medially across the ischiorectal fossa and supplies the external anal sphincter, the mucous membrane of the lower half of the anal canal, and the perianal skin.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 137
Incorrect
-
All of the following cause bronchoconstriction, EXCEPT for:
Your Answer:
Correct Answer: Adrenaline
Explanation:Factors causing bronchoconstriction:
- Via muscarinic receptors
- Parasympathetic stimulation
- Stimulation of irritant receptors
- Inflammatory mediators e.g. histamine, prostaglandins, leukotrienes
- Beta-blockers
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 138
Incorrect
-
A 64-year-old man presents with an acute episode of gout. He has a history of chronic heart failure and hypertension. His current medications include ramipril and furosemide.
Which of the following statements regarding the treatment of gout is true? Select ONE answer only.Your Answer:
Correct Answer: Colchicine has a role in prophylactic treatment
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.
Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.
Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.
Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.
NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
-
-
Question 139
Incorrect
-
Which of the following globin chains makes up haemoglobin A2 (HbA2)?
Your Answer:
Correct Answer: Two alpha chains and two delta chains
Explanation:Haemoglobin is a 64.4 kd tetramer consisting of two pairs of globin polypeptide chains: one pair of alpha-like chains, and one pair of non-alpha chains. The chains are designated by Greek letters, which are used to describe the particular haemoglobin (e.g., Hb A is alpha2/beta2).
Two copies of the alpha-globin gene (HBA2, HBA1) are located on chromosome 16 along with the embryonic zeta genes (HBZ). There is no substitute for alpha globin in the formation of any of the normal haemoglobins (Hb) following birth (e.g., Hb A, Hb A2, and Hb F). Thus, absence any alpha globin, as seen when all 4 alpha-globin genes are inactive or deleted is incompatible with extrauterine life, except when extraordinary measures are taken.
A homotetramer of only alpha-globin chains is not thought to occur, but in the absence of alpha chains, beta and gamma homotetramers (HbH and Bart’s haemoglobin, respectively) can be found, although they lack cooperativity and function poorly in oxygen transport. The single beta-globin gene (HBB) resides on chromosome 11, within a gene cluster consisting of an embryonic beta-like gene, the epsilon gene (HBE1), the duplicated and nearly identical fetal, or gamma globin genes (HBG2, HBG1), and the poorly expressed delta-globin gene (HBD). A heme group, consisting of a single molecule of protoporphyrin IX co-ordinately bound to a single ferrous (Fe2+) ion, is linked covalently at a specific site to each globin chain. If the iron is oxidized to the ferric state (Fe3+), the protein is called methaemoglobin.
Alpha globin chains contain 141 amino acids (residues) while the beta-like chains contain 146 amino acids. Approximately 75 percent of haemoglobin is in the form of an alpha helix. The non helical stretches permit folding of the polypeptide upon itself. Individual residues can be assigned to one of eight helices (A-H) or to adjacent non helical stretches.
Heme iron is linked covalently to a histidine at the eighth residue of the F helix (His F8), at residue 87 of the alpha chain and residue 92 of the beta chain. Residues that have charged side groups, such as lysine, arginine, and glutamic acid, lie on the surface of the molecule in contact with the surrounding water solvent. Exposure of the hydrophilic (charged) amino acids to the aqueous milieu is an important determinant of the solubility of haemoglobin within the red blood cell and of the prevention of precipitation.
The haemoglobin tetramer is a globular molecule (5.0 x 5.4 x 6.4 nm) with a single axis of symmetry. The polypeptide chains are folded such that the four heme groups lie in clefts on the surface of the molecule equidistant from one another.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 140
Incorrect
-
A 25-year old male is brought to the emergency room after a traffic accident. Upon examination, there was tenderness and erythema on the right acromioclavicular joint, with notable step deformity. On radiographic imaging, there is a superior elevation of the clavicle, a twice than normal coracoclavicular distance, and absence of fracture.
Which of the following structure/s is/are likely to have ruptured?Your Answer:
Correct Answer: Acromioclavicular ligament, coracoclavicular ligament and joint capsule
Explanation:Acromioclavicular joint injuries account for more than forty percent of all shoulder injuries. Mild injuries are not associated with any significant morbidity, but severe injuries can lead to significant loss of strength and function of the shoulder. Acromioclavicular injuries may be associated with a fractured clavicle, impingement syndromes, and more rarely neurovascular insults.
The AC joint is a diarthrodial joint defined by the lateral process of the clavicle articulating with the acromion process as it projects anteriorly off the scapula. The joint is primarily stabilized by the acromioclavicular ligament, which is composed of an anterior, posterior, inferior, and superior component. Of note, the superior portion of the AC ligament is the most important component for the stability of the AC joint. Supporting structures include two coracoclavicular ligaments (trapezoid and conoid ligaments), which provide vertical stability, as well as the coracoacromial ligament.
Patients with an AC joint injury typically present with anterosuperior shoulder pain and will describe a mechanism of injury of blunt trauma to the abducted shoulder or landing on an outstretched arm, suggestive of this type of injury. They may describe pain radiating to the neck or shoulder, which is often worse with movement or when they try to sleep on the affected shoulder. On examination, the clinician may observe swelling, bruising, or a deformity of the AC joint, depending on the degree of injury. The patient will be tender at that location. They may have a restriction in the active and passive range of motion secondary to pain. Piano key sign may be seen, with an elevation of the clavicle that rebounds after inferior compression.
Standard X-rays are adequate to make a diagnosis of acromioclavicular joint injury and should be used to evaluate for other causes of traumatic shoulder pain.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 141
Incorrect
-
Regarding haemoglobin, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Haemoglobin synthesis occurs in mature erythrocytes.
Explanation:Haemoglobin is composed of four polypeptide globin chains each with its own iron containing haem molecule. Haem synthesis occurs largely in the mitochondria by a series of biochemical reactions commencing with the condensation of glycine and succinyl coenzyme A under the action of the key rate-limiting enzyme delta-aminolevulinic acid (ALA) synthase. The globin chains are synthesised by ribosomes in the cytosol. Haemoglobin synthesis only occurs in immature red blood cells.
There are three types of haemoglobin in normal adult blood: haemoglobin A, A2 and F:
– Normal adult haemoglobin (HbA) makes up about 96 – 98 % of total adult haemoglobin, and consists of two alpha (α) and two beta (β) globin chains.
– Haemoglobin A2 (HbA2), a normal variant of adult haemoglobin, makes up about 1.5 – 3.5 % of total adult haemoglobin and consists of two α and two delta (δ) globin chains.
– Foetal haemoglobin is the main Hb in the later two-thirds of foetal life and in the newborn until approximately 12 weeks of age. Foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin.
Red cells are destroyed by macrophages in the liver and spleen after , 120 days. The haem group is split from the haemoglobin and converted to biliverdin and then bilirubin. The iron is conserved and recycled to plasma via transferrin or stored in macrophages as ferritin and haemosiderin. An increased rate of haemoglobin breakdown results in excess bilirubin and jaundice. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 142
Incorrect
-
Molecules with a molecular weight of less than which of the following are filtered freely at the glomerular filtration barrier:
Your Answer:
Correct Answer: 7000 Da
Explanation:Molecular weight is the main factor in determining whether a substance is filtered or not – molecules < 7 kDa in molecular weight are filtered freely e.g. glucose, amino acids, urea, ions but larger molecules are increasingly restricted up to 70 kDa, above which filtration is insignificant. Negatively charged molecules are further restricted, as they are repelled by negative charges, particularly in the basement membrane. Albumin has a molecular weight of 69 kDa and is negatively charged, thus only very small amounts are filtered (and all of the filtered albumin is reabsorbed in the proximal tubule), whereas small molecules such as ions, glucose, amino acids and urea pass the filter without hindrance. This means that ultrafiltrate is virtually protein free, but otherwise has an identical composition of that of plasma. The epithelial lining of the Bowman's capsule consists of a single layer of cells called podocytes. The glomerular capillary endothelium is perforated by pores (fenestrations) which allow plasma components with a molecular weight of < 70 kDa to pass freely.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 143
Incorrect
-
In adult advanced life support, which of the following best describes the correct administration of adrenaline for a non-shockable rhythm:
Your Answer:
Correct Answer: Give 1 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Explanation:IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 144
Incorrect
-
If the null hypothesis is wrongly rejected when it is actually true, this is an example of:
Your Answer:
Correct Answer: A test with a type I error
Explanation:A type I error occurs when the null hypothesis is wrongly rejected when it is actually true and we conclude that there is a difference of effect when in reality there is none (a false positive result).
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 145
Incorrect
-
A 29-year-old woman presents with night sweats, fever, and haemoptysis. A diagnosis of tuberculosis was suspected.
Which of the following statements regarding the diagnosis of tuberculosis is considered correct?Your Answer:
Correct Answer: Mycobacteria tuberculosis can be typed using a RFLP method
Explanation:Although a variety of clinical specimens may be submitted to the
laboratory to recover MTB and NTM, respiratory secretions such
as sputum and bronchial aspirates are the most common. An
early-morning specimen should be collected on three consecutive
days, although recent studies have suggested that the addition of
a third specimen does not significantly increase the sensitivity
of detecting Mycobacteria.Mycobacterium tuberculosis appear red on acid-fast staining because they take up the primary stain, which is carbolfuchsin, and is not decolorized by the acid alcohol anymore.
Culture on Lowenstein-Jensen medium should be read within 5 to 7 days after inoculation and once a week thereafter for up to 8 weeks.
Nucleic acid amplification assays designed to detect M. tuberculosis complex
bacilli directly from patient specimens can be performed in as little as 6 to 8 hours on processed specimens. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 146
Incorrect
-
A 36 year old man who is overweight with a history of gout, presents to emergency room with an acutely painful big toe which is red, hot and swollen. However, he is apyrexic and otherwise systemically well. He has been diagnosed with acute gout. The most appropriate first line treatment for him is which of the following?
Your Answer:
Correct Answer: NSAIDs
Explanation:The first line treatment for acute gout includes NSAIDs like diclofenac, indomethacin or naproxen. In patients in whom NSAIDs are contraindicated, not tolerated or ineffective, colchicine is an alternative. In those who cannot tolerate or who are resistant to NSAIDs and colchicine, oral or parenteral corticosteroids are an effective alternative. In acute monoarticular gout, intra-articular injection of a corticosteroid can be used occasionally. In acute gout. allopurinol is not used in the actual treatment, but its use should be continued during an acute attack if the patient is already established on long term therapy.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 147
Incorrect
-
Anatomical barriers to infection include all of the following EXCEPT:
Your Answer:
Correct Answer: Mucociliary escalator in the gastrointestinal tract
Explanation:Anatomical barriers to infection include:tight junctions between cells of the skin and mucosal membranesthe flushing action of tears, saliva and urinethe mucociliary escalator in the respiratory tract (together with the actions of coughing and sneezing)the acidic pH of gastric and vaginal secretionsthe acidic pH of the skin (maintained by lactic acid and fatty acids in sebum)enzymes such as lysozyme found in saliva, sweat and tearspepsin present in the stomachbiological commensal flora formed on the skin and the respiratory, gastrointestinal and genitourinary tracts which protect the host by competing with pathogenic bacteria for nutrients and attachment sites and by producing antibacterial substances
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 148
Incorrect
-
Regarding carbon dioxide transport in the blood, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Deoxygenated haemoglobin acts as a buffer for H+ ions.
Explanation:CO2generated in the tissues and water combine to form carbonic acid which readily dissociates to form HCO3-and H+. The first part of this reaction is very slow in plasma, but is accelerated dramatically by the enzyme carbonic anhydrase present in red blood cells. Bicarbonate is therefore formed preferentially in red cells, from which it freely diffuses down its concentration gradient into plasma where it is transported to the lungs. The red cell membrane is impermeable to H+ions which remain in the cell. To maintain electroneutrality, Cl-ions diffuse into the cell to replace HCO3-, an effect known as the chloride shift. Deoxygenated haemoglobin acts as a buffer for H+, allowing the reaction to continue.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 149
Incorrect
-
Clostridium tetani causes which of the following infectious diseases:
Your Answer:
Correct Answer: Tetanus
Explanation:Clostridium tetani causes tetanus.
Scarlet fever is caused by Streptococcus pyogenes.
Toxic shock syndrome is caused by Staphylococcus aureus or Streptococcus pyogenes.
Gas gangrene is primarily caused by Clostridium perfringens.
Pseudomembranous colitis is commonly caused by Clostridium difficile. -
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 150
Incorrect
-
Which type of collagen is initially laid down in early wound healing:
Your Answer:
Correct Answer: III
Explanation:Fibroblasts migrate to the wound (about 2 – 5 days after wounding), proliferate and secrete extracellular matrix comprising mainly collagen (type III) and fibronectin to plug the gap.
-
This question is part of the following fields:
- Pathology
- Wound Healing
-
-
Question 151
Incorrect
-
You're called to a cardiac arrest in your Emergency Department resuscitation area. The rhythm strip is shown in the diagram below. Defibrillation has already been attempted three times on the patient. You intended to administer amiodarone, but your department has informed you that it is not available. In these circumstances, if amiodarone is not available, which of the following drugs is recommended by the ALS guidelines?
Your Answer:
Correct Answer: Lidocaine
Explanation:If amiodarone is unavailable in VF/pVT arrests, lidocaine at a dose of 1 mg/kg can be used instead, according to the latest ALS guidelines. If amiodarone has already been given, no lidocaine should be given.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 152
Incorrect
-
The qSOFA score is a bedside prompt designed to identify patients with suspected infection who are at greater risk for a poor outcome outside of the intensive care unit.
Which of the following is one of the criteria used in the qSOFA score? Select ONE answer only.Your Answer:
Correct Answer: Respiratory rate >22
Explanation:In February 2016 the Society of Critical Care Medicine published a JAMA article reformatting the definitions of sepsis in an attempt to overcome the shortcomings of the old definitions.
The main changes are a new definition of sepsis, the replacement of the SIRS criteria with the quick Sepsis-related Organ Failure Assessment (qSOFA), and the complete removal of “severe sepsis” as an entity.
The new definition of sepsis is that it is “life-threatening organ dysfunction caused by a dysregulated host response to infection.”
Septic shock is “a subset of sepsis in which underlying circulatory and cellular metabolism abnormalities are profound enough to increase mortality.”
In essence this means that septic shock is sepsis plus the following, despite adequate fluid resuscitation:
Vasopressors required to maintain a MAP > 65 mmHg
Serum lactate > 2 mmol/l
The qSOFA score is a bedside prompt designed to identify patients with suspected infection who are at greater risk for a poor outcome outside of the intensive care unit. It uses the following three criteria:
Hypotension (SBP < 100 mmHg)
Tachypnoea (RR > 22)
Altered mental status (GCS < 15)
The presence of 2 or more of the qSOFA criteria near the onset of infection is associated with greater risk of death or a prolonged intensive care unit stay. -
This question is part of the following fields:
- Pathology
- Pathology Of Infections
-
-
Question 153
Incorrect
-
A 15-year-old male is admitted to a rehabilitation centre with a history of multiple strokes, myopathy and learning disabilities since childhood. He is under the care of a multidisciplinary team, and his genetic testing reports show the presence of a mitochondrial disorder.
Which one of the following diseases does this patient most likely have?Your Answer:
Correct Answer: MELAS
Explanation:Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria. Most cases are maternally inherited, as we inherit our mitochondrial DNA from our mothers only, although mutations in nuclear DNA cause some cases.
Examples of Mitochondrial Diseases include:
1. Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)
2. Mitochondrial epilepsy with ragged red fibres (MERRF)
3. Leber’s hereditary optic neuropathy (LHON)
4. Diabetes mellitus and deafness (DAD)
5. Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)
6. Leigh syndrome (subacute sclerosing encephalopathy).Red-green colour blindness and G6PD deficiency have an X-linked recessive pattern of inheritance.
Tay-Sachs Disease and spinal muscular atrophy have an autosomal recessive pattern of inheritance.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 154
Incorrect
-
Regarding the human cell, which of the following cell organelles is responsible for the production of ATP:
Your Answer:
Correct Answer: Mitochondria
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.
Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.
Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 155
Incorrect
-
Regarding co-amoxiclav, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Clavulanic acid acts to inhibit cross-linking of bacterial peptidoglycan polymers.
Explanation:Co-amoxiclav consists of amoxicillin with the beta-lactamase inhibitor clavulanic acid. Clavulanic acid itself has no significant antibacterial activity but, by inactivating beta-lactamases, it makes the combination active against beta-lactamase-producing bacteria that are resistant to amoxicillin.The most common adverse effects of co-amoxiclav include nausea, vomiting, skin rash and diarrhoea. Pseudomembranous colitis should be considered if a person develops severe diarrhoea during or after treatment with co-amoxiclav. Cholestatic jaundice can occur either during or shortly after the use of co-amoxiclav. An epidemiological study has shown that the risk of acute liver toxicity was about 6 times greater with co-amoxiclav than with amoxicillin. Cholestatic jaundice is more common in patients above the age of 65 years and in men; these reactions have only rarely been reported in children. Jaundice is usually self-limiting and very rarely fatal.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 156
Incorrect
-
Which of the following is most likely to cause a homonymous hemianopia:
Your Answer:
Correct Answer: Posterior cerebral artery stroke
Explanation:A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 157
Incorrect
-
Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 158
Incorrect
-
Which of the following nerves supplies the abductor pollicis brevis?
Your Answer:
Correct Answer: The recurrent branch of the median nerve
Explanation:Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 159
Incorrect
-
A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer.
You instantly send a blood sample to check for lithium levels.
What is the usual therapeutic range for lithium?Your Answer:
Correct Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l.
The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 160
Incorrect
-
A 70-year-old patient develops bacteraemia following peripheral cannulation.
Which of these bacteria is the most likely cause of the infection?Your Answer:
Correct Answer: Staphylococcus epidermidis
Explanation:The commonest implicated organisms in hospital-acquired bacteraemia following cannulation are Staphylococcus aureus and Staphylococcus epidermidis.
The risk is directly proportional to the length of time in-situ. Peripheral cannula should be replaced after 48 hours. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 161
Incorrect
-
A 26 year old male presents to emergency room with a 2 day history of burning pain when passing urine, accompanied by a green urethral discharge. Gonorrhoea is suspected. The first line antibiotic for this condition is which of the following?
Your Answer:
Correct Answer: Ceftriaxone
Explanation:When there is a high suspicion of gonorrhoea from clinical features, empiric treatment should be commenced whilst waiting for laboratory confirmation.
The first line treatment for uncomplicated anogenital and pharyngeal disease includes ceftriaxone 500 mg IM (single dose) + azithromycin 1 g orally as a single dose. This covers concomitant chlamydia infection. For all people who have been treated for gonorrhoea, a test of cure is recommended -
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 162
Incorrect
-
External haemorrhoids may cause anal pain. When explaining to your patient why it does so, which of the following nerves will you point out as being affected?
Your Answer:
Correct Answer: Pudendal nerve
Explanation:The pain associated with external haemorrhoids is carried by a branch of the pudendal nerve, specifically the somatic fibres (S2-S4).
It innervates the external anal sphincter and most of the skin over the perineum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 163
Incorrect
-
On which of the following is preload primarily dependent?
Your Answer:
Correct Answer: End-diastolic volume
Explanation:Preload refers to the initial stretching of the cardiac myocytes before contraction. It is therefore related to muscle sarcomere length. The sarcomere length cannot be determined in the intact heart, and so, other indices of preload are used, like ventricular end-diastolic volume or pressure. The end-diastolic pressure and volume of the ventricles increase when venous return to the heart is increased, and this stretches the sarcomeres, which increase their preload.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 164
Incorrect
-
A 38-year-old taxi driver sustained blunt force trauma to his anterior chest from the steering wheel of his car after falling asleep while driving headlong into an oncoming HGV lorry. Bruising around his sternum was observed, which appears to be the central point of impact.
Which of the following structures is most likely injured by the blunt force trauma?Your Answer:
Correct Answer: Right ventricle
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:
Anterior (or sternocostal) – Right ventricle
Posterior (or base) – Left atrium
Inferior (or diaphragmatic) – Left and right ventricles
Right pulmonary – Right atrium
Left pulmonary – Left ventricle -
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 165
Incorrect
-
A 23-year-old female has been prescribed a medication in the first trimester of pregnancy due to a life-threatening medical problem. After delivery, the foetus is found to have nasal hypoplasia, stippling of his bones and atrophy of bilateral optic discs along with growth retardation.
Which ONE of the following drugs has this woman most likely received?Your Answer:
Correct Answer: Warfarin
Explanation:Warfarin is teratogenic and can cause a host of abnormalities in the growing foetus. These include hypoplasia of the nasal bridge, stippling of the epiphyses, multiple ophthalmic complications, growth retardation, pectus carinatum, atrial septal defect, ventriculomegaly and a patent ductus arteriosus.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 166
Incorrect
-
You review an 83-year-old woman who has stage 5 chronic kidney disease. She has a number of electrolyte problems.
Which ONE of the following decreases the renal reabsorption of phosphate?Your Answer:
Correct Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.
The main actions of parathyroid hormone are:
Increases plasma calcium concentration
Decreases plasma phosphate concentration
Increases osteoclastic activity (increasing calcium and phosphate resorption from bone)
Increases renal tubular reabsorption of calcium
Decreases renal phosphate reabsorption
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)
Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 167
Incorrect
-
The sensory innervation of the oropharynx is provided by which of the following nerves:
Your Answer:
Correct Answer: Glossopharyngeal nerve
Explanation:Each subdivision of the pharynx has a different sensory innervation:the nasopharynx is innervated by the maxillary nervethe oropharynx is innervated by the glossopharyngeal nervethe laryngopharynx is innervated by the vagus nerve.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 168
Incorrect
-
A 60-year-old female has a past medical history of diverticular disease. She now presents in the clinic with crampy abdominal pain. The nurse at the triage suggests prescribing hyoscine butyl bromide to help relieve the abdominal pain. However, after administering this treatment, the patient develops a side-effect to the medication.
What side-effect of using hyoscine butyl bromide is she MOST likely to develop out of the following?Your Answer:
Correct Answer: Dry mouth
Explanation:Hyoscine butylbromide is an antispasmodic drug that blocks muscarinic receptors and reduces intestinal motility. It is used for gastrointestinal and genitourinary smooth muscle spasms and symptomatic relief of IBS.
It has the following side-effects:
1. Constipation
2. Dizziness
3. Drowsiness
4. Dry mouth
5. Dyspepsia
6. Flushing
7. Headache
8. Nausea and vomiting
9. Palpitations
10. Skin reactions
11. Tachycardia
12. Urinary disorders
13. Disorders of vision -
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
-
-
Question 169
Incorrect
-
Which of the following is NOT a pharmacological effect of beta-blockers:
Your Answer:
Correct Answer: Reduced AV conduction time
Explanation:Effects of beta-blockers:
Cardiovascular system:
Reduce blood pressure
Reduce heart rate, contractility and cardiac output
Increase AV conduction time, refractoriness and suppress automaticityEye:
Reduce intraocular pressureRespiratory system:
Cause bronchoconstriction -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 170
Incorrect
-
A 52-year old male comes to the out-patient department for a groin mass that protrudes when standing. The patient notes that it is reducible when lying down. On physical examination, there is presence of a cough impulse. The initial assessment is hernia. Further investigation reveals that the mass lies lateral to the epigastric vessels.
Among the types of hernia, which is the most likely diagnosis of the case above?Your Answer:
Correct Answer: Indirect inguinal hernia
Explanation:Inguinal hernias can present with an array of different symptoms. Most patients present with a bulge in the groin area, or pain in the groin. Some will describe the pain or bulge that gets worse with physical activity or coughing. Symptoms may include a burning or pinching sensation in the groin. These sensations can radiate into the scrotum or down the leg. It is important to perform a thorough physical and history to rule out other causes of groin pain. At times an inguinal hernia can present with severe pain or obstructive symptoms caused by incarceration or strangulation of the hernia sac contents. A proper physical exam is essential in the diagnosis of an inguinal hernia. Physical examination is the best way to diagnose a hernia. The exam is best performed with the patient standing. Visual inspection of the inguinal area is conducted first to rule out obvious bulges or asymmetry in groin or scrotum. Next, the examiner palpates over the groin and scrotum to detect the presence of a hernia. The palpation of the inguinal canal is completed last. The examiner palpates through the scrotum and towards the external inguinal ring. The patient is then instructed to cough or perform a Valsalva manoeuvre. If a hernia is present, the examiner will be able to palpate a bulge that moves in and out as the patient increases intra abdominal pressure through coughing or Valsalva.
Groin hernias are categorized into 2 main categories: inguinal and femoral.
Inguinal hernias are further subdivided into direct and indirect. An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum, and can be reduced superiorly then superolaterally. A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
A femoral hernia is a protrusion into the femoral ring. The borders of the femoral ring are the femoral vein laterally, Cooper’s ligament posteriorly, the iliopubic tract/inguinal ligament anteriorly and lacunar ligament medially.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 171
Incorrect
-
Which of the following factors decreases insulin secretion:
Your Answer:
Correct Answer: Catecholamines
Explanation:Factors that increase insulin secretion:
↑ Blood glucose
↑ Amino acids
↑ Fatty acids
Glucagon
Secretin
AcetylcholineFactors that decrease insulin secretion:
↓ Blood glucose
Somatostatin
Catecholamines -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 172
Incorrect
-
A 23 year old woman has noticed her skin seems to have a yellow tinge and presents to the emergency room. On examination she is found to have jaundice and mild splenomegaly, and blood tests show that her Hb is 79 g/L. She only takes one regular medication. The medication that is most likely to cause haemolytic anaemia is:
Your Answer:
Correct Answer: Mefenamic acid
Explanation:Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) that is used short-term (7 days or less) to treat mild to moderate pain in adults and children who are at least 14 years old. Mefenamic acid is also used to treat menstrual pain. It has only minor anti-inflammatory properties and has occasionally been associated with diarrhoea and haemolytic anaemia. If these occur, treatment should be discontinued.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 173
Incorrect
-
Blood flows from the left atrium into the left ventricle via:
Your Answer:
Correct Answer: The mitral valve
Explanation:Blood flows from the right atrium into the right ventricle via the tricuspid atrioventricular valve and from the left atrium into the left ventricle via the mitral atrioventricular valve. Blood is ejected from the right ventricle through the pulmonary semilunar valve into the pulmonary artery and from the left ventricle via the aortic semilunar valve into the aorta.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 174
Incorrect
-
What is the main mechanism of action of metoclopramide:
Your Answer:
Correct Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 175
Incorrect
-
Regarding alteplase, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Alteplase is commonly associated with hypotensive effects.
Explanation:Alteplase is a recombinant tissue-type plasminogen activator (tPA), a naturally occurring fibrin-specific enzyme that has selectivity for activation of fibrin-bound plasminogen. It has a short half-life of 3 – 4 minutes and must be given by continuous intravenous infusion but is not associated with antigenic or hypotensive effects, and can be used in patients when recent streptococcal infections or recent use of streptokinase contraindicates the use of streptokinase.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 176
Incorrect
-
Regarding paracetamol, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It has anti-pyretic action.
Explanation:Paracetamol is a non-opioid analgesic, similar in efficacy to aspirin, with antipyretic properties but no anti-inflammatory properties. It is well absorbed orally and does not cause gastric irritation. Paracetamol is a suitable first-line choice for most people with mild-to-moderate pain, and for combination therapy.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 177
Incorrect
-
Given a patient with dislocation of the patella, which muscle is the most important to address during rehabilitation to prevent recurrent dislocation?
Your Answer:
Correct Answer: Vastus medialis
Explanation:Patellar dislocation is a disabling musculoskeletal disorder which predominantly affects younger people who are engaged in multidirectional physically active pursuits. Conservative (non-operative) treatment is the treatment of choice for FTPD (first time patellar dislocation). Quadriceps strengthening exercises are considered one of the principal management aims for people following FTPD. A United Kingdom (UK) survey of physiotherapy practice has shown that quadriceps strengthening and specific-vastus medialis obliquus (VMO) or distal vastus medialis (VM) muscle strengthening or recruitment exercises were two of the most frequently used interventions for this population. Specific VM exercises are favoured in some quarters based on the assumption that the VM has an important role in preventing excessive lateral patellar translation.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 178
Incorrect
-
A patient with a recent diagnosis of Hepatitis B would like to find out further information regarding his diagnosis and prognosis.
Which among the following statements is considered true regarding Hepatitis B?Your Answer:
Correct Answer: 60-65% of patients that contract hepatitis B show subclinical disease
Explanation:As the immune response is activated, the virus is slowly cleared from the system, and most patients become non-infectious. In adults, about 50% of infections are asymptomatic; 20% to 30% of patients exhibit clinical jaundice but have a benign resolution of the infection. Therefore, about 80% of infections do not cause serious sequelae. The risk for chronic infection is inversely proportional to age at time of infection, with approximately 90% of infants and only 3% of adults developing a chronic infection.
Individuals with a chronic infection have a higher risk of liver disease, such as cirrhosis or hepatic carcinoma. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 179
Incorrect
-
Which of the following is NOT a typical side effect of digoxin:
Your Answer:
Correct Answer: Hypokalaemia
Explanation:Digoxin does not cause hypokalaemia, but hypokalaemia does potentiate digoxin toxicity. The adverse effects of digoxin are frequently due to its narrow therapeutic window and include:
Cardiac adverse effects – Sinoatrial and atrioventricular block, Premature ventricular contractions, PR prolongation and ST-segment depression
Nausea, vomiting and diarrhoea
Blurred or yellow vision
CNS effects – weakness, dizziness, confusion, apathy, malaise, headache, depression, psychosis
Thrombocytopenia and agranulocytosis (rare)
Gynaecomastia in men in prolonged administration -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 180
Incorrect
-
Calcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels. The phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.
A phenylalkylamine calcium-channel blocker is, for example, which of the following?Your Answer:
Correct Answer: Verapamil
Explanation:Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance.
They can be used for a variety of things, including:
Hypertension
Angina
Atrial fibrillation
MigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.
Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.
The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:
Amlodipine
Felodipine
Nifedipine
NimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.
Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.
In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 181
Incorrect
-
A 62-year-old female complains of pain in her right upper quadrant. An abdominal ultrasound is conducted, and a big gallstone is discovered. The radiologist who performs the scan speaks with you about the physiology of the gallbladder and biliary tract.
During a 24-hour period, how much bile does the gallbladder produce?
Your Answer:
Correct Answer: 400-800 ml
Explanation:The gallbladder stores and concentrates bile, which is produced by the liver. In a 24-hour period, around 400 to 800 mL of bile is generated. The breakdown of fats into fatty acids, the removal of waste materials, and cholesterol homeostasis are all crucial functions of bile.
Bile is created on a constant basis, however it is only necessary after a meal has been consumed. The elimination of water and ions concentrates bile in the gallbladder, which is subsequently stored for later use. Food induces the release of the hormone cholecystokinin from the duodenum, the contraction of the gallbladder, and the relaxation of the sphincter of Oddi. The bile then enters the duodenum.
Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:
Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.
Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 182
Incorrect
-
Which of the following best describes digoxin:
Your Answer:
Correct Answer: A positive inotrope and negative chronotrope
Explanation:Digoxin is a cardiac glycoside used in the treatment of atrial fibrillation and flutter, and congestive cardiac failure. It acts by inhibiting the membrane Na/K ATPase in cardiac myocytes. This raises intracellular sodium concentration and increases intracellular calcium availability indirectly via Na/Ca exchange. The increase in intracellular calcium levels causes an increases the force of myocardial contraction (positive inotrope), and slows the heart rate (negative chronotrope).
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 183
Incorrect
-
A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer:
Correct Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 184
Incorrect
-
A 36-year-old man presented to the emergency room with a two-week history of shortness of breath, fevers, and malaise. A chest X-ray was ordered and the results confirmed the diagnosis of a right middle lobe pneumonia.
Which of the following structures of the heart lies closest to the consolidation?Your Answer:
Correct Answer: Right atrium
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:
Anterior (or sternocostal) – Right ventricle
Posterior (or base) – Left atrium
Inferior (or diaphragmatic) – Left and right ventricles
Right pulmonary – Right atrium
Left pulmonary – Left ventricleThe silhouette sign of Felson is with respect to the right middle lobe. The right heart border should have a distinct appearance due to the right atrium abutting aerated right middle lobe. The consolidation in the right middle lobe has resulted in loss of this silhouette.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 185
Incorrect
-
A novel anti-tuberculosis medicine was compared to standard treatment and shown to cut the risk of death from 30 to 10 per 1000 people. How many patients would need to be treated (number need to treat (NNT)) in order to prevent 10 additional tuberculosis deaths:
Your Answer:
Correct Answer: 500
Explanation:The risk of mortality in the control group (usual therapy) minus the risk of death in the treatment group equals the absolute risk reduction (ARR) of treatment.
30/1000 minus 10/1000 = 20/1000 = 0.02NNT = 1/ARR = 1/0.02 = 50
As a result, 50 people would need to be treated in order to prevent one additional fatality, and 500 people would need to be treated in order to avoid 10 additional deaths. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 186
Incorrect
-
A 59-year-old woman presents with a history of tiredness and weight gain and a diagnosis of hypothyroidism is suspected.
Which of these changes is likely to appear first in primary hypothyroidism?Your Answer:
Correct Answer: Increased thyroid-stimulating hormone (TSH)
Explanation:The earliest biochemical change seen in hypothyroidism is an increase in thyroid-stimulating hormone (TSH) levels.
Triiodothyronine (T3) and thyroxine (T4) levels are normal in the early stages.
TBG levels are generally unchanged in primary hypothyroidism.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 187
Incorrect
-
A 22-year-old presents with acute severe asthma. He takes a drug prescribed by her GP but cannot recall the name and is receiving regular salbutamol nebulisers. His current potassium level is 2.8 mmol/l.
Which drug is least likely to have caused his hypokalaemia?
Your Answer:
Correct Answer: Spironolactone
Explanation:Serious hypokalaemia can occur in severe asthma and the effect can be potentiated by concomitant treatment with theophyllines like aminophylline, corticosteroids, thiazide and loop diuretics, and hypoxia. Plasma-potassium concentration should be monitored in severe asthma.
Spironolactone, a potassium-sparing diuretic, is not likely to have contributed to patients hypokalaemia.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 188
Incorrect
-
A 64-year-old lady attends the emergency department with a known brain tumour. Her left eye is directed outwards and downwards, she can't open it, and her pupil is fixed and dilated. The tumour is most likely compressing which of the following structures:
Your Answer:
Correct Answer: Oculomotor nerve
Explanation:The oculomotor nerve is the third cranial nerve. It is the main source of innervation to the extraocular muscles and also contains parasympathetic fibres which relay in the ciliary ganglion. Damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis. The clinical manifestations of third cranial nerve dysfunction reflect its constituent parts.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 189
Incorrect
-
A 18 year old with known asthma presents himself to ED with acute breathlessness and wheeze for the past 20 minutes. On examination he is tachypneic and tachycardic. His oxygen saturations are 96% on air. What is the first line treatment for acute asthma:
Your Answer:
Correct Answer: Salbutamol
Explanation:High-dose inhaled short-acting beta2-agonists are the first line treatment for acute asthma(salbutamol or terbutaline). Oxygen should only been given to hypoxaemic patients (to maintain oxygen saturations of 94 – 98%). A pressurised metered dose inhaler with spacer device is preferred in patients with moderate to severe asthma (4 puffs initially, followed by 2 puffs every 2 minutes according to response, up to 10 puffs, whole process repeated every 10 – 20 minutes if necessary). The oxygen-driven nebuliser route is recommended for patients with life-threatening features or poorly responsive severe asthma (salbutamol 5 mg at 15 – 30 minute intervals). Continuous nebulisation should be considered in patients with severe acute asthma that is poorly responsive to initial bolus dose (salbutamol at 5 – 10 mg/hour) The intravenous route should be reserved for those in whom inhaled therapy cannot be used reliably.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 190
Incorrect
-
Which of the following is NOT an adverse effect associated with statin therapy:
Your Answer:
Correct Answer: Aplastic anaemia
Explanation:Adverse effects of statins include:, Headache, Epistaxis, Gastrointestinal disorders (such as constipation, flatulence, dyspepsia, nausea, and diarrhoea), Musculoskeletal and connective tissue disorders (such as myalgia, arthralgia, pain in the extremity, muscle spasms, joint swelling, and back pain), Hyperglycaemia and diabetes, Myopathy and rhabdomyolysis, Interstitial lung disease and Hepatotoxicity
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 191
Incorrect
-
A 28-year-old asthmatic patient is seen in the Emergency Department following an acute exacerbation. His symptoms start to improve when your consultant gives him a high dose of IV aminophylline.
Which of the following is correct mechanism of action of aminophylline ?Your Answer:
Correct Answer: Inhibition of phosphodiesterase
Explanation:Aminophylline has the following properties:
Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.
Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 192
Incorrect
-
A known epileptic is transported in status epilepticus by ambulance. On the way to the hospital, she took some diazepam.
Which of the following statements about diazepam is correct?Your Answer:
Correct Answer: It crosses into breast milk
Explanation:Diazepam boosts GABA’s effects, giving it sedative, hypnotic, anxiolytic, anticonvulsant, and muscle-relaxing properties. It can be administered orally, rectally, or intravenously.
With a half-life of 20-100 hours, it is a long-acting benzodiazepine. Midazolam, oxazepam, and alprazolam are examples of short-acting benzodiazepines with a half-life of less than 12 hours (Xanax).
If used in the presence of hepatic impairment, benzodiazepines can cause coma. If treatment is necessary, benzodiazepines with shorter half-lives should be used in lower doses. Diazepam is a sedative that crosses into breast milk and should be avoided by breastfeeding mothers.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 193
Incorrect
-
An injury to which nerve affects innervation to the adductor portion of the adductor magnus?
Your Answer:
Correct Answer: Posterior branch of the obturator nerve
Explanation:The nerves that supply the adductor magnus muscle have an embryologic origin from the anterior divisions of the lumbosacral plexus and include the obturator nerve, posterior division (L2-4), and the tibial portion of the sciatic nerve (L4). It is innervated by the posterior division of the obturator nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 194
Incorrect
-
When the breast cancer of a 60-year old patient metastasizes and compresses the intervertebral foramina between the fourth and fifth cervical vertebrae, as well as the fourth and fifth thoracic vertebrae, this causes back pain. Which pair of nerves is most likely affected?
Your Answer:
Correct Answer: Fifth cervical and fourth thoracic nerves
Explanation:The fifth cervical nerve passes between the fourth and fifth cervical vertebrae, and the fourth thoracic nerve passes between the fourth and fifth thoracic vertebrae. Therefore, when the cancer metastasizes in this area, they are most likely affected.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 195
Incorrect
-
A 25 year old man presents to the emergency room with abdominal pain, vomiting and constipation. A CT scan is done which is suggestive of Meckel's diverticulum. Where does the blood supply of the Meckel's diverticulum originate?
Your Answer:
Correct Answer: Superior mesenteric artery
Explanation:Meckel’s diverticulum has certain classic characteristics.
1. It lies on the antimesenteric border of the middle-to-distal ileum
2. It is approximately 2 feet proximal to the ileocaecal junction
3. It appears as a blind-ended tubular outpouching of bowel
4. It is about 2 inches long,
5. It occurs in about 2% of the population,
6. It may contain two types of ectopic tissue (gastric and pancreatic).
7. The diverticulum is supplied by the superior mesenteric artery.
8. Proximal to the major duodenal papilla the duodenum is supplied by the gastroduodenal artery (branch of the coeliac trunk)
9. Distal to the major duodenal papilla it is supplied by the inferior pancreaticoduodenal artery (branch of superior mesenteric artery).
10. The arterial supply to the jejunoileum is from the superior mesenteric artery. -
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 196
Incorrect
-
1-alpha-hydroxylase is a cytochrome p450 enzyme that is involved in the production of vitamin D's hormonally active metabolite.
Which of the following promotes the activity of 1-alpha-hydroxylase?Your Answer:
Correct Answer: Parathyroid hormone
Explanation:1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney.
The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is promoted by parathyroid hormone or hypophosphatemia.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 197
Incorrect
-
A 7-year old boy is referred to the Paediatrics Department due to slurred speech. Upon further examination, the attending physician noted the presence of dysdiadochokinesia, intention tremors, and nystagmus. An MRI is taken, which revealed a brain tumour.
Which of the following options is the most probable diagnosis given the clinical features of the patient?Your Answer:
Correct Answer: Astrocytoma of cerebellum
Explanation:Pilocytic astrocytoma (PCA), previously known as cystic cerebellar astrocytoma or juvenile pilocytic astrocytoma, was first described in 1931 by Harvey Cushing, based on a case series of cerebellar astrocytomas; though he never used these terms but rather described a spongioblastoma. They are low-grade, and usually well-circumscribed tumours, which tend to occur in young patients. By the World Health Organization (WHO) classification of central nervous system tumours, they are considered grade I gliomas and have a good prognosis.
PCA most commonly occurs in the cerebellum but can also occur in the optic pathway, hypothalamus, and brainstem. They can also occur in the cerebral hemispheres, although this tends to be the case in young adults. Presentation and treatment vary for PCA in other locations. Glial cells include astrocytes, oligodendrocytes, ependymal cells, and microglia. Astrocytic tumours arise from astrocytes and are the most common tumour of glial origin. The WHO 2016 categorized these tumours as either diffuse gliomas or other astrocytic tumours. Diffuse gliomas include grade II and III diffuse astrocytomas, grade IV glioblastoma, and diffuse gliomas of childhood. The other astrocytic tumours group include PCA, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, and anaplastic pleomorphic xanthoastrocytoma.
PCA can present with symptoms secondary to the posterior fossa mass effect. This may include obstructive hydrocephalus, with resultant headache, nausea and vomiting, and papilledema. If hydrocephalus occurs before the fusion of the cranial sutures (<18-months-of-age), then an increase in head circumference will likely occur. Lesions of the cerebellar hemisphere result in peripheral ataxia, dysmetria, intention tremor, nystagmus, and dysarthria. In contrast, lesions of the vermis cause a broad-based gait, truncal ataxia, and titubation. Posterior fossa lesions can also cause cranial nerve palsies. Diplopia may occur due to abducens palsy from the stretching of the nerve. They may also have blurred vision due to papilledema. Seizures are rare with posterior fossa lesions.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 198
Incorrect
-
All of the following statements are considered true regarding likelihood ratios, except:
Your Answer:
Correct Answer: If less than one, indicates that the information increases the likelihood of the suspected diagnosis
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 199
Incorrect
-
A 22-year-old woman is brought in by ambulance from her GP surgery with suspected meningitis. She has been given a dose of benzylpenicillin already.
What is the mechanism of action of benzylpenicillin? Select ONE answer only.Your Answer:
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.
An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
Mechanism of action
Examples
Inhibition of cell wall synthesis
Penicillins
Cephalosporins
Vancomycin
Disruption of cell membrane function
Polymyxins
Nystatin
Amphotericin B
Inhibition of protein synthesis
Macrolides
Aminoglycosides
Tetracyclines
Chloramphenicol
Inhibition of nucleic acid synthesis
Quinolones
Trimethoprim
5-nitroimidazoles
Rifampicin
Anti-metabolic activity
Sulfonamides
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 200
Incorrect
-
During quiet respiration, position of the right oblique fissure can be marked by a line drawn on the thoracic wall that:
Your Answer:
Correct Answer: Begins at the spinous process of T4, crosses the fifth intercostal space laterally and follows the contour of rib 6 anteriorly.
Explanation:During quiet respiration, the approximate position of the right oblique fissure can be marked by a line on the thoracic wall that begins at the spinous process of vertebra T4, crosses the fifth intercostal space laterally and then follows the contour of rib 6 anteriorly.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
SESSION STATS - PERFORMANCE PER SPECIALTY
