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Question 1
Incorrect
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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: Aponeurosis of internal oblique
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
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Question 2
Incorrect
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Which of the following vitamins is not paired correctly with its deficiency syndrome:
Your Answer:
Correct Answer: Vitamin B12 - Wernicke-Korsakoff syndrome
Explanation:Clinical Effects of vitamin deficiency include:
Vitamin C – Scurvy
Thiamine (Vitamin B1) – Beriberi/Wernicke-Korsakoff syndrome
Vitamin B12 – Megaloblastic anaemia/Subacute combined degeneration of spinal cord
Folate – Megaloblastic anaemia
Vitamin D – Osteomalacia/Rickets
Vitamin K – Defective clotting
Vitamin A – Blindness -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 3
Incorrect
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A patient complains of headache and visual loss. CT scan demonstrates a lesion of the temporal lobe. What type of visual field defect would you most expect to see in this patient:
Your Answer:
Correct Answer: Contralateral homonymous superior quadrantanopia
Explanation:Axons from the lateral geniculate nucleus (LGN) carry visual information, via the upper and lower optic radiations, to the visual cortex in the occipital lobe:
The upper optic radiation carries fibres from the superior retinal quadrants (corresponding to the inferior visual field quadrants) and travels through the parietal lobe to reach the visual cortex.
The lower optic radiation carries fibres from the inferior retinal quadrants (corresponding to the superior visual field quadrants) and travels through the temporal lobe to reach the visual cortex of the occipital lobe. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 4
Incorrect
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When the pulmonary artery is completely blocked, what is the ventilation over perfusion ratio for the area that it supplies?
Your Answer:
Correct Answer: Infinity
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion.
A pulmonary artery carries deoxygenated blood from the right side of the heart to the lungs. When a large pulmonary embolus completed blocked a pulmonary artery the alveoli were ventilated but not perfused at all, then the V/Q ratio would be infinity.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 5
Incorrect
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How is filtered K+mainly reabsorbed in the thick ascending limb of the loop of Henle:
Your Answer:
Correct Answer: Secondary active transport via Na + /K + /2Cl - cotransporter
Explanation:Around 30% of filtered K+is reabsorbed in the thick ascending limb of the loop of Henle, primarily via the luminal Na+/K+/2Cl-cotransporter, but there is also significant paracellular reabsorption, encouraged by the positive potential in the tubular lumen.
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This question is part of the following fields:
- Physiology
- Renal
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Question 6
Incorrect
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The arterial blood gas (ABG) of a 56-year-old woman shows type A lactic acidosis.
What is the most likely cause of her lactic acidosis?
Your Answer:
Correct Answer: Left ventricular failure
Explanation:Lactic acidosis is a common finding in critically ill patients and commonly associated with other serious underlying pathologies. It occurs when pH is <7.35 and lactate is >5 mmol/L. Anion gap is increased in lactic acidosis.
Acquired lactic acidosis is classified into two subtypes:
Type A: lactic acidosis due to tissue hypoxia and
Type B: due to non-hypoxic processes affecting the production and elimination of lactateSome causes of type A and type B lactic acidosis include:
Type A lactic acidosis
Left ventricular failure
Severe anaemia
Shock (including septic shock)
Asphyxia
Cardiac arrest
CO poisoning
Respiratory failure
Severe asthma and COPDType B lactic acidosis:
Regional hypoperfusion
Renal failure
Liver failure
Sepsis (non-hypoxic sepsis)
Thiamine deficiency
Alcoholic ketoacidosis
Diabetic ketoacidosis
Cyanide poisoning
Methanol poisoning
Biguanide poisoning -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 7
Incorrect
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A 26 year old horse rider has a bad fall and sustains a neck injury which displays the following signs:
- ability to extend the wrist against gravity
- paralysis of the hands, trunk, and legs
- absent sensation in the fingers and medial upper arms
- normal sensation over the thumbs
- absent sensation in chest, abdomen, and legs
What is the neurological level of the injury?Your Answer:
Correct Answer: C6
Explanation:C1 – C4 INJURY
Most severe of the spinal cord injury levels; paralysis in arms, hands, trunk and legs; patient may not be able to breathe on his or her own, cough, or control bowel or bladder movements; ability to speak is sometimes impaired or reducedC5 INJURY
Person can raise his or her arms and bend elbows; likely to have some or total paralysis of wrists, hands, trunk and legs; can speak and use diaphragm, but breathing will be weakenedC6 INJURY
Nerves affect wrist extension; paralysis in hands, trunk and legs, typically; should be able to bend wrists back; can speak and use diaphragm, but breathing will be weakenedC7 INJURY
Nerves control elbow extension and some finger extension; most can straighten their arm and have normal movement of their shouldersC8 INJURY
Nerves control some hand movement; should be able to grasp and release objectsC5 – Elbow flexors (biceps, brachialis)
C6 – Wrist extensors (extensor carpi radialis longus and brevis)
C7 – Elbow extensors (triceps)
C8 – Finger flexors (flexor digitorum profundus) to the middle fingerC5 – Elbow flexed at 90 degrees, arm at the patient’s side and forearm supinated
C6 – Wrist in full extension
C7 – Shoulder is neutral rotation, adducted and in 90 degrees of flexion with elbow in 45 degrees of flexion
C8 –Full flexed position of the distal phalanx with the proximal finger joints stabilized in a extended position -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 8
Incorrect
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For the treatment of his atrial fibrillation, a 67-year-old man is about to begin taking warfarin. He also takes a number of other medications.
Which of the following medications will prevent warfarin from working?Your Answer:
Correct Answer: Phenytoin
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 inhibit the effects of warfarin, resulting in a lower INR. To remember the most commonly encountered cytochrome p450 enzyme inducers, use the mnemonic PC BRASS:
P– Phenytoin
C– Carbamazepine
B– Barbiturates
R– Rifampicin
A– Alcohol (chronic ingestion)
S– Sulphonylureas
S– Smoking -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 9
Incorrect
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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.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 10
Incorrect
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Which one these is an example of a cause of an exudate?
Your Answer:
Correct Answer: Subphrenic abscess
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.
Some common causes of exudates are: pneumonia, empyema, lung cancer, breast cancer, cancer of the pleura, SLE, rheumatoid arthritis, pericarditis, subphrenic abscess, chylothorax.
Myxoedema, nephrotic syndrome, congestive cardiac failure, and liver cirrhosis all cause TRANSUDATE.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 11
Incorrect
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.
The stomach mucous neck cells secrete which of the following substances?
Your Answer:
Correct Answer: Bicarbonate
Explanation:Foveolar cells, also known as gastric mucous-neck cells, are cells that line the stomach mucosa and are found in the necks of the gastric pits. Mucus and bicarbonate are produced by these cells, which prevent the stomach from digesting itself. At pH 4, the mucous allows the acid to penetrate the lining, while below pH 4, the acid is unable to do so. Viscous fingering is the term for this procedure.
The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:
Cell type/ Substance secreted/ Function of secretion
Parietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogen
Parietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorption
Chief cells/ Pepsinogen/ Protein digestion
Chief cells/ Gastric lipase/ Fat digestion
G-cells/ Gastrin/ Stimulates gastric acid secretion
Enterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretion
Mucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acid
D-cells/ Somatostatin/ Inhibits gastric acid secretion -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 12
Incorrect
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A 54-year-old man returns from a recently holiday on a cruise ship with a dry cough and a fever. Today he has also had several episodes of diarrhoea and has developed bilateral pleuritic chest pain. He states that he is short of breath, most notably on exertion. He had been prescribed amoxicillin by the cruise ship doctor a few days earlier but has not seen any improvement.
Which of the following is the most likely causative organism? Select ONE answer only.Your Answer:
Correct Answer: Legionella pneumophila
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 13
Incorrect
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Which of the following is NOT a common side effect of adenosine:
Your Answer:
Correct Answer: Yellow vision
Explanation:Common side effects of adenosine include:
Apprehension
Dizziness, flushing, headache, nausea, dyspnoea
Angina (discontinue)
AV block, sinus pause and arrhythmia (discontinue if asystole or severe bradycardia occur) -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 14
Incorrect
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In the treatment of hypertensive episodes in pheochromocytoma, which of the following medication types is administered as first-line management:
Your Answer:
Correct Answer: Alpha-blockers
Explanation:The first line of management in controlling blood pressure and preventing intraoperative hypertensive crises is to use a combination of alpha and beta-adrenergic inhibition. In phaeochromocytoma, alpha-blockers are used to treat hypertensive episodes in the short term. Tachycardia can be managed by the careful addition of a beta-blocker, preferably a cardioselective beta-blocker, once alpha blockade has been established. Long term management of pheochromocytoma involves surgery.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 15
Incorrect
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Which of the following muscles inserts into the patella?
Your Answer:
Correct Answer: The quadriceps femoris complex
Explanation:The quadriceps femoris muscle translates to “four-headed muscle” from Latin. It bears this name because it consists of four individual muscles; rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius. Out of all four muscles, only the rectus femoris crosses both the hip and knee joints. The others cross only the knee joint. These muscles differ in their origin, but share a common quadriceps femoris tendon which inserts into the patella. The function of the quadriceps femoris muscle is to extend the leg at the knee joint and to flex the thigh at the hip joint.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 16
Incorrect
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A 50-year-old woman has an anaphylactic reaction following accidental ingestion peanuts at a restaurant. She is a known hypertensive on atenolol 50 mg daily and BP is well controlled. She is also on amlodipine 5 mg daily. Two doses of IM adrenaline has been given without improvement.
Which medication may prove helpful in this patient?
Your Answer:
Correct Answer: IM Glucagon
Explanation:Resistant to the effects of adrenaline in anaphylaxis is seen in patients taking beta-blockers.
Glucagon can be used to overcome the effects of the beta-blockade if initial doses of adrenaline are unsuccessful in patients taking beta-blockers.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 17
Incorrect
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An increased anion gap metabolic acidosis is typically caused by which of the following?
Your Answer:
Correct Answer: Propylene glycol overdose
Explanation:Causes of a raised anion gap acidosis can be remember using the mnemonic MUDPILES:
-Methanol
-Uraemia (in renal failure)
-Diabetic ketoacidosis
-Propylene glycol overdose
-Infection/Iron overdose/Isoniazid/Inborn errors of metabolism
-Lactic acidosis
-Ethylene glycol overdose
-Salicylate overdose -
This question is part of the following fields:
- Physiology
- Renal
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Question 18
Incorrect
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A 26-year-old man is involved in a motorcycle accident that results in an open fracture of his tibia and fibula. The nerve that innervates peroneus tertius is damaged as a consequence of his injuries.
Peroneus tertius receives its innervation from which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Deep peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.
Peroneus longus is innervated by the superficial peroneal nerve.
Peroneus tertius is innervated by the deep peroneal nerve. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 19
Incorrect
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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
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Question 20
Incorrect
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The causative organism for an infection in a patient you are reviewing is a facultative anaerobe.
Which of these is a facultative anaerobic organism?Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Facultative anaerobic bacteria make energy in the form of ATP by aerobic respiration in an oxygen rich environment and can switch to fermentation in an oxygen poor environment.
Examples of facultative anaerobes are:
Staphylococcus spp.
Listeria spp.
Streptococcus spp.
Escherichia coliMycobacterium tuberculosis, and Pseudomonas aeruginosa are obligate aerobe. They require oxygen to grow
Campylobacter jejuni and Clostridium spp are obligate anaerobes.
They live and grow in the absence of oxygen. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 21
Incorrect
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A 58-year-old male has cellulitis of his left leg. Because he is allergic to penicillin, you start him on erythromycin.
What is erythromycin's mechanism of action?Your Answer:
Correct Answer: Inhibition of protein synthesis
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolide antibiotics. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and thereby protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered to the infection site as a result.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 22
Incorrect
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A newborn baby girl is delivered vaginally to a 19-year old female, however with complications due to cephalopelvic disproportion. Upon examination by the attending paediatrician, there is a notable 'claw hand' deformity of the left, and sensory loss of the ulnar aspect of the left distal upper extremity.
What is the most probable diagnosis of the case above?Your Answer:
Correct Answer: Klumpke’s palsy
Explanation:Klumpke palsy, named after Augusta Dejerine-Klumpke, is a neuropathy involving the lower brachial plexus. In contrast, the more common Erb–Duchenne palsy involves the more cephalic portion of the brachial plexus C5 to C6. The brachial plexus is a bundle of individual nerves that exit between the anterior and middle scalene muscles in the anterior lateral and basal portion of the neck. Although the most common anatomical presentation of the brachial plexus is between the anterior and middle scalene, there are variations, with the most common being penetration of the anterior scalene. The main mechanism of injury to the lower brachial plexus is hyper-abduction traction, and depending on the intensity, it will lead to signs and symptoms consistent with a neurological insult.
The most common aetiology resulting in Klumpke palsy is a hyper-abduction trauma to the arm that has enough intensity to traction the lower brachial plexus. Trauma during birth can cause brachial plexus injuries, but again hyper-abduction and traction forces to the upper extremity are usually present.
The history presented by the patient usually depicts a long axis hyper-abduction traction injury with high amplitude and velocity. The typical patient presentation is a decrease of sensation along the medial aspect of the distal upper extremity along the C8 and T1 dermatome. The patient might also present myotome findings that can range from decreasing muscular strength to muscular atrophy and positional deformity. For example, if the neurological damage has led to muscular atrophy and tightening, the patient may present with a claw hand. This deformity presents a finger and wrist flexion. The patient may also describe the severe pain that starts at the neck and travels down the medial portion of the arm. One other sign of a lower brachial plexus injury is Horner syndrome; because of its approximation to the T1 nerve root, it may damage the cephalic sympathetic chain. If this happens, the patient will develop ipsilateral ptosis, anhidrosis, and miosis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Incorrect
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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
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Question 24
Incorrect
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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
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Question 25
Incorrect
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Regarding flucloxacillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It is resistant to bacterial beta-lactamases.
Explanation:Flucloxacillin is unique in that it is beta-lactamase stable and it can be used in infections caused by beta-lactamase producing staphylococci e.g. S. aureus. It is acid-stable and can therefore be given by mouth as well as by injection. It is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. The most common adverse effects of flucloxacillin include nausea, vomiting, skin rash, and diarrhoea. Cholestatic jaundice and hepatitis may occur very rarely, up to two months after treatment with flucloxacillin has been stopped. Administration for more than 2 weeks and increasing age are risk factors. First line treatment of animal and human bites is co-amoxiclav.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 26
Incorrect
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You examine a 48-year-old patient who has had proximal weakness, hypertension, and easy bruising in the past. She exhibits considerable face fullness and truncal obesity on examination. You diagnose her�with Cushing's syndrome.
When would her random cortisol level likely be abnormal?Your Answer:
Correct Answer: 2400 hrs
Explanation:Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep.
The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 27
Incorrect
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You are seeing a child with known mitochondrial disease who has presented breathlessness and cough. Which of the following best describes the function of mitochondria:
Your Answer:
Correct Answer: Energy production
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
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Question 28
Incorrect
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A 23-year-old has a known diagnosis of HIV. Blood is sent to the laboratory for tests.
AIDS be diagnosed at a CD4 counts below?Your Answer:
Correct Answer: 200 cells/mm 3
Explanation:A normal CD4 count ranges from 500-1000 cells/mm3.
At CD4 count of less than 350 cells/mm3 treatment with anti-retroviral therapy should be considered.
At a CD4 count of >200 cells/mm3 AIDS is diagnosed.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 29
Incorrect
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Thyroid cancer has spread to the regional lymph nodes of a patient as seen in a staging CT scan.
The lymph from the thyroid gland will drain directly to which of the following nodes?Your Answer:
Correct Answer: Deep lateral cervical lymph nodes
Explanation:Lymphatic drainage of the thyroid gland involves the lower deep cervical, prelaryngeal, pretracheal, and paratracheal nodes. The paratracheal and lower deep cervical nodes, specifically, receive lymphatic drainage from the isthmus and the inferior lateral lobes. The superior portions of the thyroid gland drain into the superior pretracheal and cervical nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 30
Incorrect
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A 40-year-old male visits his family physician with the complaint of a high-grade fever for the past five days. A complete blood count report shows the presence of neutrophilia.
Which one of the following facts regarding neutrophilia is accurate?Your Answer:
Correct Answer: It can be caused by eclampsia
Explanation:A total neutrophil count of greater than 7.5 x 109/L is called neutrophilia. Typhoid fever usually causes leukopenia or neutropenia. Both localised and generalised bacterial infections can cause neutrophilia.
Metabolic disorders such as
– gout
– eclampsia
– uraemia
can also cause neutrophilia.Acute neutrophilia, in which immature neutrophils can be seen, is referred to as a left shift and can be seen in conditions such as appendicitis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 31
Incorrect
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Regarding hepatitis C, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Anti-HCV IgG antibodies are diagnostic of acute infection.
Explanation:Anti-HCV IgG antibodies indicate exposure to hepatitis C but this could be acute, chronic or resolved infection. If the antibody test is positive, HCV RNA should be tested for, which if positive indicates that a person has current infection with active hepatitis C.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 32
Incorrect
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Which of the following leukaemias is most common in children in the UK:
Your Answer:
Correct Answer: Acute lymphoblastic leukaemia
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. There is a secondary rise after the age of 40 years. 85% of cases are of B-cell lineage and have an equal sex incidence; there is a male predominance for the 15% of T-cell lineage.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 33
Incorrect
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Regarding water and electrolyte absorption in the small intestine, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Na+ enters the cell across the apical membrane against its concentration gradient by both membrane channels and transporter protein mechanisms.
Explanation:As the contents of the intestine are isotonic with body fluids and mostly have the same concentration of the major electrolytes, their absorption is active. Water cannot be moved directly, but follows osmotic gradients set up by the transport of ions, primarily mediated by the sodium pump.Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions, against their respective concentration gradients. This leads to a low intracellular concentration of Na+ and a high intracellular concentration of K+. The low intracellular concentration of Na+ ensures a movement of Na+ from the intestinal contents into the cell down its concentration gradient by both membrane channels and transporter protein mechanisms. Na+ is then rapidly pumped again by the basolateral sodium pump. K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl- against its concentration gradient (Cl- having entered the cell across the luminal membrane down its concentration gradient).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 34
Incorrect
-
Achlorhydria is diagnosed in a 37-year-old individual who has had recurring episodes of gastroenteritis. This is an autoimmune illness of the gastric parietal cells that causes insufficient stomach acid production.
Damage to stomach parietal cells will alter the secretion of which other substance?Your Answer:
Correct Answer: Intrinsic factor
Explanation:Achlorhydria is an autoimmune illness of the gastric parietal cells that causes insufficient stomach acid production. The parietal cells that have been injured are unable to create the necessary amount of stomach acid. As a result, the pH of the stomach rises, food digestion suffers, and the risk of gastroenteritis rises.
The secretion of hydrochloric acid and intrinsic factor is controlled by the gastric parietal cells, which are epithelial cells in the stomach. These cells can be found in the gastric glands, the fundus lining, and the stomach body.
In response to the following three stimuli, the stomach parietal cells release hydrochloric acid:
H2 Histamine receptors are stimulated by histamine (most significant contribution)
Acetylcholine stimulates M3 Receptors via parasympathetic action.
CCK2 receptors are stimulated by Gastrin.Intrinsic factor, which is essential for vitamin B12 absorption, is also produced by stomach parietal cells.
Omeprazole is a proton pump inhibitor that is both selective and irreversible. It inhibits the H+/K+-ATPase system present on the secretory membrane of gastric parietal cells, which lowers stomach acid secretion.
Ranitidine inhibits histamine H2-receptors in a competitive manner. The reversible inhibition of H2-receptors in gastric parietal cells reduces both the volume and concentration of gastric acid. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 35
Incorrect
-
Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer:
Correct Answer: 75% of cases occur before the age of 6 years.
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. 85% of cases are of B-cell lineage. Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. There is great variation in the chance of individual patients achieving a long-term cure based on a number of biological variables. Approximately 25% of children relapse after first-line therapy and need further treatment but overall 90% of children can expect to be cured. The cure rate in adults drops significantly to less than 5% over the age of 70 years.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 36
Incorrect
-
You suspected a fungal nail infection in a 50-year-old man who presented with an itchy, scaly rash between his toes and a thicker, discoloured nail on his big toe that has been there for almost one month already. Which of the following tests is most likely to confirm your suspected diagnosis?
Your Answer:
Correct Answer: Nail clippings for microscopy and culture
Explanation:Nail clippings for microscopy and culture are a diagnostic test for fungal infection. Because some fungi are restricted to the lower parts of the nail, clippings should be taken from the discoloured or brittle parts and cut back as far as possible from the free edge.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 37
Incorrect
-
Regarding fat digestion, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Chylomicrons are exocytosed from enterocytes to enter lacteals and thus the lymphatic system.
Explanation:Dietary fat is chiefly composed of triglycerides (esters of free fatty acids and glycerol which may be saturated or unsaturated). The essential fatty acids are linoleic acid and alpha-linoleic acid, which cannot be manufactured in the body. Dietary fat provides 37 kJ (9 kcal) of energy per gram. Fats are digested almost entirely in the small intestine and are only released from the stomach into the duodenum at the rate at which they can be digested.
Pancreatic lipase is the most significant enzyme for fat digestion. In the duodenum fat is emulsified by bile acids, a process where larger lipid droplets are broken down into much smaller droplets providing a greater surface area for enzymatic digestion. Micelles are arranged so that hydrophobic lipid molecules lie in the centre, surrounded by bile acids arranged such the outer region is hydrophilic. Dietary and synthesised lipids are incorporated into chylomicrons in the Golgi body, which are exocytosed from the basolateral membrane to enter lacteals and thus the lymphatic system. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 38
Incorrect
-
A 50-year-old man managed by the renal team for stage 4 chronic kidney disease which appears to be deteriorating presents with a history of shortness of breath and ankle oedema. His most recent blood tests shows low calcium levels.
Which of these increases the renal reabsorption of calcium?Your Answer:
Correct Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH), a polypeptide containing 84 amino acids, is the principal hormone that controls free calcium in the body.
Its main actions are:
Increases osteoclastic activity
Increases plasma calcium concentration
Decreases renal phosphate reabsorption
Decreases plasma phosphate concentration
Increases renal tubular reabsorption of calcium
Increases calcium and phosphate absorption in the small intestine
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 39
Incorrect
-
What is the average healing time for a femoral shaft fracture under normal circumstances? Choose ONE answer.
Your Answer:
Correct Answer: 12 weeks
Explanation:The process of fracture healing occurs naturally after traumatic bone disruption and begins with haemorrhage, then progresses through Inflammatory, reparative, and remodelling stages
Average healing times of common fractures are:
Femoral shaft: 12 weeks
Tibia: 10 weeks
Phalanges: 3 weeks
Metacarpals: 4-6 weeks
Distal radius: 4-6 weeks
Humerus: 6-8 weeks -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 40
Incorrect
-
Regarding the management of gout, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Allopurinol may cause an acute attack of gout when first started.
Explanation:Allopurinol is a treatment for the prevention of gout. The initiation of treatment may precipitate an acute attack, and should be covered with an NSAID or colchicine, continued for at least one month after the hyperuricaemia has been corrected. Colchicine is not indicated for long term prevention of gout. NSAIDs are first line for acute gout; colchicine is an alternative in whom NSAIDs are contraindicated, not tolerated or ineffective (including in people taking anticoagulants). Ibuprofen is not recommended for acute gout, given it has only weak anti-inflammatory properties; naproxen, diclofenac or indometacin are indicated instead.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 41
Incorrect
-
The flow of ions across a cell membrane causes electrical activity in biological tissues. Excitable tissues are specialized tissues that may generate a significant electrical signal called an action potential, which is followed by a refractory period.
Which set of ion channels is responsible for the refractory period?Your Answer:
Correct Answer: Sodium channels
Explanation:A refractory period follows each action potential. The absolute refractory time and the relative refractory period are two divisions of refractory periods. Because the sodium channels seal after an AP, they enter an inactive state during which they cannot be reopened regardless of membrane potential, this time occurs.
The sodium channels slowly come out of inactivation during the relative refractory period that follows. During this time, a stronger stimulus than that required to initiate an action potential can excite the cell. The strength of the stimulus required early in the relative refractory period is relatively high, and it steadily decreases as more sodium channels recover from the inactivation of the refractory period.
Nodes of Ranvier are periodic holes in a myelinate axon when there is no myelin and the axonal membrane is exposed. There are no gated ion channels in the portion of the axon covered by the myelin sheath, but there is a high density of ion channels in the Nodes of Ranvier. Action potentials can only occur at the nodes as a result of this.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 42
Incorrect
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In the foetus at 4 months gestation, where does haematopoiesis mainly occur?
Your Answer:
Correct Answer: Liver and spleen
Explanation:The first place that haematopoiesis occurs in the foetus is in the yolk sac. Later on, it occurs in the liver and spleen, which are the major hematopoietic organs from about 6 weeks until 6 – 7 months gestation. At this point, the bone marrow becomes the most important site. Haemopoiesis is restricted to the bone marrow in normal childhood and adult life.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 43
Incorrect
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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.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 44
Incorrect
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Regarding threadworms, which of the following statements is CORRECT:
Your Answer:
Correct Answer: First line treatment of threadworms is with mebendazole.
Explanation:First line treatment of threadworms is with mebendazole, with treatment of the whole family, and a repeat treatment after 2 weeks. Threadworms live in the large bowel, but direct multiplication of worms does not occur here. Threadworms most commonly infect children, and may be symptomatic or cause pruritus ani.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 45
Incorrect
-
You come across a 60-year-old woman with a history of chronic pancreatitis. Today she is complaining of epigastric pain. She has blood tests done especially to review her cholecystokinin levels.
Which of the following is a cholecystokinin (CCK) releasing site?Your Answer:
Correct Answer: I-cells in the upper small intestine
Explanation:The I-cells in the duodenum generate and release cholecystokinin (CCK), a peptide hormone. It has a crucial role in the digestion process as a hormonal regulator.
CCK cells are concentrated in the proximal small intestine, and when food is consumed, the hormone is produced into the bloodstream. The presence of partly digested lipids and proteins in the duodenum is one of the most powerful stimulus for CCK synthesis.
CCK’s key physiological effects include:
Encourages the pancreas to release digesting enzymes into the small intestine.
Stimulates gallbladder contraction and sphincter of Oddi relaxation, resulting in bile delivery into the duodenum.
Gastric emptying is inhibited, and gastric acid output is reduced.
Satiety induction is a process that involves inducing a feeling of fullness. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 46
Incorrect
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Which of the following is an adverse effect of carbamazepine:
Your Answer:
Correct Answer: Aplastic anaemia
Explanation:Common adverse effects include nausea and vomiting, sedation, dizziness, headache, blurred vision and ataxia. These adverse effects are dose related and are most common at the start of treatment.
Other adverse effects include:
Allergic skin reactions (and rarely, more serious dermatological conditions)
Hyponatraemia (avoid concomitant use with diuretics)
Leucopenia, thrombocytopenia and other blood disorders including aplastic anaemia
Hepatic impairment -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 47
Incorrect
-
Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer:
Correct Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis.
At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine.
Muscle paralysis occurs gradually due to the competitive blockade.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 48
Incorrect
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Question 49
Incorrect
-
A 70-year-old patient diagnosed with Cushing's syndrome, has a history of weight gain, hypertension, and easy bruising.
Which of the following statements about Cushing's syndrome is NOT true?Your Answer:
Correct Answer: Menorrhagia is a common feature
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.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome.
Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep. The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.Insulin resistance causes hyperglycaemia, which is a frequent symptom. Insulin resistance can produce acanthosis nigricans in the axilla and around the neck, as well as other skin abnormalities.
In contrast to menorrhagia, elevated testosterone levels are more likely to produce amenorrhoea or oligomenorrhoea. Infertility in women of reproductive age can also be caused by high androgen levels.
A dexamethasone suppression test or a 24-hour urine free cortisol collection can both be used to establish the existence of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 50
Incorrect
-
Dysuria and urinary frequency are symptoms of a 29-year-old woman. A urine dipstick is used to detect the presence of blood, protein, leucocytes, and nitrites in the urine. You diagnose a urinary tract infection and give antibiotics to the patient.
In the United Kingdom, which of the following antibiotics has the highest percentage of E.coli resistance?Your Answer:
Correct Answer: Trimethoprim
Explanation:In the United Kingdom, antibiotic resistance is becoming a significant factor in the treatment of urinary tract infections and pyelonephritis. E. coli (the main causative organism of both urinary tract infections and acute pyelonephritis) resistance to the following antibiotics in laboratory-processed urine specimens is:
30.3 percent trimethoprim (varies by area from 27.1 to 33.4 percent )
19.8 percent co-amoxiclav (varies by area from 10.8 to 30.7 percent )
Ciprofloxacin (Cipro): 10.6% (varies by area from 7.8 to 13.7 percent )
Cefalexin has a concentration of 9.9%. (varies by area from 8.1 to 11.4 percent ) -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 51
Incorrect
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Regarding ampicillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Ampicillin may cause a widespread maculopapular rash in a patient with glandular fever.
Explanation:Ampicillin is a broad-spectrum antibiotic, active against certain Gram-positive and Gram-negative organisms but is inactivated by penicillinases (similar to amoxicillin in spectrum). Ampicillin is associated with high levels of resistance, therefore it is often not appropriate for blind treatment of infection. It is principally indicated for the treatment of exacerbations of chronic bronchitis and middle ear infections, both of which may be due to Streptococcus pneumoniae and H. influenzae, and for urinary tract infections.
Maculopapular rashes commonly occur with ampicillin (and amoxicillin) but are not usually related to true penicillin allergy. They almost always occur in patients with glandular fever; thus broad-spectrum penicillins should not be used for blind treatment of a sore throat. The risk of rash is also increased in patients with acute or chronic lymphocytic leukaemia or in cytomegalovirus infection.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 52
Incorrect
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Surface area of the absorptive surface in the small intestine is increased by all but which of the following:
Your Answer:
Correct Answer: Teniae coli
Explanation:Factors increasing the surface area include:The small intestine is very long – about 5 m in length.The inner wall of the small intestine is covered by numerous folds of mucous membrane called plicae circulares.The lining of the small intestine is folded into many finger-like projections called villi.The surface of the villi is covered with a layer of epithelial cells which, in turn, have many small projections called microvilli that project towards the lumen of the intestine (forming the brush border).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 53
Incorrect
-
Which cervical interspace is most likely injured if a patient presents with difficulty of shoulder abduction and elbow flexion, pain in the right shoulder and lateral arm, and decreased sensation over the deltoid and lateral arm?
Your Answer:
Correct Answer: C4-C5
Explanation:In the setting of cervical radiculopathy, because the nerve root of a spinal nerve is compressed or otherwise impaired, the pain and symptomatology can spread far from the neck and radiates to arm, neck, chest, upper back and/or shoulders. Often muscle weakness and impaired deep tendon reflexes are noted along the course of the spinal nerve.
Cervical radiculopathy is almost always unilateral, although, in rare cases, both nerves at a given level may be impacted. Those rare presentations can confound physical diagnosis and require acceleration to advanced imaging especially in cases of trauma. If there is nerve impingement, the affected side will be reduced relative to the unaffected side. Reduction in strength of muscles innervated by the affected nerve is also significant physical finding.
For a C4-C5 injury, the following symptoms may present:
Weakness in the deltoid muscle (front and side of the shoulder) and upper arm
Shoulder pain
Numbness along the outside of the upper arm -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 54
Incorrect
-
A 20-year-old with type I diabetes mellitus has an episode of hypoglycaemia following inadvertent administration of too much insulin.
The mechanism by which insulin causes glucose to be transported into cells is?
Your Answer:
Correct Answer: Facilitated diffusion
Explanation:The only mechanism by which insulin facilitates uptake of glucose into cells is by facilitated diffusion through a family of hexose transporters.
The major transporter used for glucose uptake is GLUT4. GLUT4 is made available in the plasma membrane by the action of insulin.
When insulin concentrations are low, GLUT4 transporters are present in cytoplasmic vesicles, where they are cannot be used for transporting glucose. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 55
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.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 56
Incorrect
-
A 22-year-old man arrives at the emergency department with a sore throat, low-grade fever, and malaise. His partner has infectious mononucleosis, which was recently diagnosed. In this situation, which of the following cells is the most proliferative:
Your Answer:
Correct Answer: Lymphocytes
Explanation:Histologic findings in EBV infectious mononucleosis: Oropharyngeal epithelium demonstrates an intense lymphoproliferative response in the cells of the oropharynx. The lymph nodes and spleen show lymphocytic infiltration primarily in the periphery of a lymph node.
Relative lymphocytosis (≥ 60%) plus atypical lymphocytosis (≥ 10%) are the characteristic findings of Epstein Barr virus (EBV) infectious mononucleosis. -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 57
Incorrect
-
During anaerobic respiration, what is the net generation of ATP molecules:
Your Answer:
Correct Answer: 2
Explanation:In anaerobic respiration, two ATP molecules are produced for every glucose molecule, as opposed to the 38 molecules of ATP produced in aerobic respiration.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 58
Incorrect
-
Which of the following is typically a cause of a normal anion gap metabolic acidosis:
Your Answer:
Correct Answer: Diarrhoea
Explanation:FUSEDCARS can be used to remember some of the causes of a normal anion gap acidosis:
Fistula (pancreaticoduodenal)
Ureteroenteric conduit
Saline administration
Endocrine (hyperparathyroidism)
Diarrhoea
Carbonic anhydrase inhibitors (e.g. acetazolamide)
Ammonium chloride
Renal tubular acidosis
Spironolactone -
This question is part of the following fields:
- Physiology
- Renal
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Question 59
Incorrect
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A 55-year-old woman with mild dyspepsia seeks advice from her pharmacist on how to deal with her symptoms. In the first instance, the pharmacist advises her to take an over-the-counter antacid. She buys an antacid that contains aluminium hydroxide, which relieves her symptoms but has a negative side effect.
She's most likely to have developed which of the following side effects?Your Answer:
Correct Answer: Constipation
Explanation:Aluminium hydroxide is a common antacid that is used to treat ulcer dyspepsia and non-erosive gastro-oesophageal reflux disease.
When antacids containing aluminium salts are given to patients with renal impairment, there is a risk of accumulation and aluminium toxicity. If renal function is normal, aluminium accumulation does not appear to be a risk.
Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.
Magnesium-based antacids are generally laxative, whereas aluminium-based antacids can be constipating. Renal impairment, angioedema, and anaphylaxis are not significantly increased.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 60
Incorrect
-
A 29-year-old volunteer returns from a recent trip to the middle east with profuse watery diarrhoea. You make a diagnosis of cholera and organize a hospital admission for rehydration with intravenous fluids.
What is the mechanism of action of cholera toxin?
Your Answer:
Correct Answer: ADP-ribosylation of the G regulatory protein
Explanation:Cholera is caused by Vibrio cholerae, a motile, Gram-negative, curved bacillus. It is transmitted through water and food (especially seafood) and is primarily a disease seen in developing countries where there is poor sanitation and lack of safe water supplies.
The cholera toxin leads to stimulation of adenyl cyclase, ADP-ribosylation of the G regulatory protein, inactivation of GTPase leading to active outpouring of NaCl.
The cholera toxin consists of an A (the toxin) and B subunit. The B subunit attaches to the gut mucosa and presents the A subunit to the cell. The toxin stimulates adenyl cyclase by irreversible ADP-ribosylation of the GTP binding domain of adenyl cyclase leading to the opening of chloride channels resulting in an outpouring of NaCl and water into the lumen of the gut and causing secretory diarrhoea.
Incubation period is between 2 and 5 days, but can be as short as just a few hours.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 61
Incorrect
-
A 54-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.
Which of the following is the patient's preferred drug treatment?Your Answer:
Correct Answer: 25% of the mean arterial pressure over the first hour
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.
Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.
The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.
An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 62
Incorrect
-
Which of the following is NOT typically associated with eosinophilia:
Your Answer:
Correct Answer: Whooping cough
Explanation:An eosinophil leucocytosis is defined as an increase in blood eosinophils above 0.4 x 109/L.It is most frequently due to:
Allergic diseases (e.g. bronchial asthma, hay fever, atopic dermatitis, urticaria)
Parasites (e.g. hookworm, ascariasis, tapeworm, schistosomiasis)
Skin diseases (e.g. psoriasis, pemphigus, urticaria, angioedema)
Drug sensitivity -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 63
Incorrect
-
Which anatomical structure is divided following an emergency department anterolateral thoracotomy?
Your Answer:
Correct Answer: Latissimus dorsi
Explanation:Thoracotomy describes an incision made in the chest wall to access the contents of the thoracic cavity. Thoracotomies typically can be divided into two categories; anterolateral thoracotomies and posterolateral thoracotomies. These can be further subdivided into supra-mammary and infra-mammary and, of course, further divided into the right or left chest. Each type of incision has its utility given certain circumstances.
A scalpel is used to sharply divide the skin along the inframammary crease overlying the fifth rib. Electrocautery is then used to divide the pectoralis major muscle and serratus anterior muscle. Visualization of the proper operative field can be achieved with the division and retraction of the latissimus dorsi. Either the fourth or fifth intercostal space is then entered after the division of intercostal muscles above the rib to ensure the preservation of the neurovascular bundle. Once the patient is properly secured to the operating table, the ipsilateral arm is raised and positioned anteriorly and cephalad to rest above the head. The incision is started along the inframammary crease and extended posterolaterally below the tip of the scapula. It is then extended superiorly between the spine and the edge of the scapula, a short distance. The trapezius muscle and the subcutaneous tissues are divided with electrocautery. The serratus anterior and latissimus dorsi muscles are identified and can be retracted. The intercostal muscles are then divided along the superior border of the ribs, and the thoracic cavity is accessed.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 64
Incorrect
-
What is nimodipine used predominantly in the treatment of?
Your Answer:
Correct Answer: Prevention and treatment of vascular spasm following subarachnoid haemorrhage
Explanation:Nimodipine is a smooth muscle relaxant that is related to nifedipine, but the effects preferentially act on cerebral arteries. It is exclusively used for the prevention and treatment of vascular spasm after an aneurysmal subarachnoid haemorrhage.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 65
Incorrect
-
Following the administration of a drug that was started a few months earlier, a patient presents with features of peripheral neuropathy.
Which of the following drugs is most likely to cause peripheral neuropathy?
Your Answer:
Correct Answer: Isoniazid
Explanation:Isoniazid, a first-line agent for the treatment of tuberculosis, has the commonest side effect of peripheral neuropathy. It occurs in up to 20% of patients taking the drug at a dose > 6 mg/kg daily.
Isoniazid combines with pyridoxine (vitamin B6) to form hydrazone, which is excreted in the urine. This causes a deficiency of biologically active pyridoxine leading to peripheral neuropathy.
Peripheral neuropathy of isoniazid is prevented by the co-administration of pyridoxine at a dose of 10 mg for each 100 mg of isoniazid given.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 66
Incorrect
-
Renin is produced by which of the following:
Your Answer:
Correct Answer: Granular cells in the wall of the afferent arteriole
Explanation:Juxtaglomerular cells are specialised smooth muscle cells mainly in the walls of the afferent arterioles (and some in the efferent arterioles) which synthesise renin.
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This question is part of the following fields:
- Physiology
- Renal
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Question 67
Incorrect
-
C-reactive protein (CRP) synthesis is predominantly stimulated by which of the following cytokines:
Your Answer:
Correct Answer: IL-6
Explanation:Activated leukocytes, adipocytes, and endothelial cells all release interleukin 6 (IL-6), a significant proinflammatory cytokine. The main downstream mediator of the acute phase response is C-reactive protein, which is predominantly produced by IL-6–dependent hepatic biosynthesis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 68
Incorrect
-
In the United Kingdom, which of the following is the most often used intravenous aesthetic:
Your Answer:
Correct Answer: Propofol
Explanation:In the United Kingdom, propofol is the most widely used intravenous anaesthetic. In adults and children, it can be used to induce or maintain anaesthesia, although it is not commonly used in newborns. It can also be used to sedate individuals in intensive care and for sedation during operations.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 69
Incorrect
-
A suicidal patient had lacerated his wrist, which resulted in an ulnar nerve injury. Which of the following will confirm the presence of an ulnar nerve injury?
Your Answer:
Correct Answer: Claw hand appearance
Explanation:An ulnar injury may result in abnormal sensations in the little finger and ring finger, usually on the palm side, weakness, and loss of coordination of the fingers.
A claw like deformity of the hand and wrist is present. Pain, numbness, decreased sensation, tingling, or burning sensation in the areas controlled by the nerve are also possible.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 70
Incorrect
-
A 23-year-old male presents to his family physician with the complaint of repeated episodes of abdominal pain and the passage of dark coloured urine every morning. He also reports increasing fatigue over the past several months. On examination, there are raised, painful red nodules over the skin of the back. Laboratory workup shows haemolytic anaemia, leukopenia and thrombocytopenia.
Which one of the following disorders is this patient most likely to have?Your Answer:
Correct Answer: Paroxysmal nocturnal haemoglobinuria
Explanation:Paroxysmal nocturnal haemoglobinuria is an acquired genetic disorder that causes a decrease in red blood cells due to a membrane defect that allows increased complement binding to RBCs, causing haemolysis. Patients complain of dark-coloured urine first in the morning due to haemoglobinuria secondary to lysis of red blood cells overnight.
Thrombosis occurs, which affects hepatic, abdominal, cerebral and subdermal veins. Thrombosis of hepatic veins can lead to Budd-Chiari syndrome, thrombosis of subdermal veins can lead to painful nodules on the skin, and thrombosis of cerebral vessels can lead to stroke. The presence of dark urine in the morning only and at no other time differentiates this condition from other conditions.
Multiple myeloma would present with bone pain, signs of radiculopathy if there were nerve root compression and a history of repeated infections.
Patients with Non-Hodgkin Lymphoma would complain of enlarged lymph nodes, fatigue, fever, weight loss and a history of repeated infections.
Acute lymphoblastic leukaemia presents more commonly in children than in adults. The patient would complain of bone pain, and on examination, there would be hepatosplenomegaly.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 71
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.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 72
Incorrect
-
A patient noticed ankle swelling and has passed very little urine over the past 24 hours. He also has nausea and vomiting, reduced urine output and his blood results reveal a sudden rise in his creatinine levels over the past 48 hours. You make a diagnosis of acute kidney injury (AKI).
Which one of these is a prerenal cause of AKI?
Your Answer:
Correct Answer: Cardiac failure
Explanation:The causes of AKI can be divided into pre-renal, intrinsic renal and post-renal causes. Majority of AKI developing in the community is due to a pre-renal causes (90% of cases).
Pre-renal causes: Haemorrhage, severe vomiting or diarrhoea, burns, cardiac failure, liver cirrhosis, nephrotic syndrome, hypotension, severe cardiac failure, NSAIDs, COX-2 inhibitors, ACE inhibitors or ARBs, Abdominal aortic aneurysm, renal artery stenosis, hepatorenal syndrome,
Intrinsic (renal) causes:
Eclampsia, glomerulonephritis, thrombosis, haemolytic-uraemic syndrome, acute tubular necrosis (ATN), acute interstitial nephritis, drugs ( NSAIDs), infection or autoimmune diseases, vasculitis, polyarteritis nodosa, thrombotic microangiopathy, cholesterol emboli, renal vein thrombosis, malignant hypertensionPost-renal causes: Renal stones, Blood clot, Papillary necrosis, Urethral stricture, Prostatic hypertrophy or malignancy, Bladder tumour, Radiation fibrosis, Pelvic malignancy, Retroperitoneal fibrosis
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 73
Incorrect
-
You intend to suture a hand wound with plain 1 percent lidocaine.
In 1 mL of plain 1 percent lidocaine solution, how much lidocaine hydrochloride is there?Your Answer:
Correct Answer: 10 mg lidocaine hydrochloride
Explanation:10 mg of lidocaine hydrochloride is contained in each 1 mL of plain 1 percent lidocaine solution.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 74
Incorrect
-
Thiopental sodium is contraindicated in which of the following:
Your Answer:
Correct Answer: Acute intermittent porphyrias
Explanation:Barbiturates induce hepatic enzymes. The enzyme gamma aminolevulinic acid synthetase, which produces porphyrins, can be induced and in susceptible patients an attack of acute intermittent porphyria can occur. Thiopental is absolutely contraindicated in these patients.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 75
Incorrect
-
A 13-year-old male presents to the Emergency Department with a heavy nosebleed. His medical record shows that he was diagnosed with Haemophilia B as a child.
What is the mode of inheritance of this disease?Your Answer:
Correct Answer: X-linked recessive
Explanation:Deficiency of Factor IX causes Haemophilia B, and like the other Haemophilia’s, it has an X-linked recessive pattern of inheritance, affecting males born to carrier mothers.
Haemophilia B is the second commonest form of haemophilia and is rarer than haemophilia A. Haemophilia B is similar to haemophilia A but is less severe. You can distinguish the two disorders by specific coagulation factor assays.
The incidence of Haemophilia B is one-fifth of that of haemophilia A.
In laboratory findings, you get prolonged APTT, normal PT and low factor IX for Haemophilia B.
There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 76
Incorrect
-
The QRS duration of a broad-complex tachyarrhythmia is:
Your Answer:
Correct Answer: Greater than or equal to 0.12 s
Explanation:It’s a broad-complex tachycardia if the QRS duration is 0.12 seconds or more. It’s a narrow-complex tachycardia if the QRS complex is shorter than 0.12 seconds. The QRS duration should be examined if the patient with tachyarrhythmia is stable.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 77
Incorrect
-
Liquefactive necrosis is most commonly seen in which of the following conditions:
Your Answer:
Correct Answer: Ischaemic stroke
Explanation:Liquefactive necrosis results in the loss of all cellular structure and the formation of a soft, semi-solid mass. This is commonly seen in the brain after a cerebral infarction.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 78
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.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 79
Incorrect
-
An X-ray of a 24-year-old female hockey player who arrives at the hospital with a left foot injury reveals an avulsion fracture of the fifth metatarsal tuberosity. Which of the following muscles is most likely responsible for the movement of the fractured fragment?
Your Answer:
Correct Answer: Fibularis brevis
Explanation:An avulsion fracture of the base of the fifth metatarsal happens when the ankle is twisted inwards.
When the ankle is twisted inwards a muscle called the fibularis brevis contracts to stop the movement and protect the ligaments of the ankle.
The base of the fifth metatarsal is where this muscle is attached. The group of lateral leg muscles that function to plantarflex the foot includes the fibularis brevis and the fibularis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 80
Incorrect
-
In the emergency room, a 28-year-old woman complains of wobbly and slurred speech, is unable to do the heel-shin test, and has nystagmus. The following signs are most likely related to damage to which of the following areas:
Your Answer:
Correct Answer: Cerebellum
Explanation:Cerebellar injury causes delayed and disorganized motions. When walking, people with cerebellar abnormalities sway and stagger.
Damage to the cerebellum can cause asynergia, the inability to judge distance and when to stop, dysmetria, the inability to perform rapid alternating movements or adiadochokinesia, movement tremors, staggering, wide-based walking or ataxic gait, a proclivity to fall, weak muscles or hypotonia, slurred speech or ataxic dysarthria, and abnormal eye movements or nystagmus.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 81
Incorrect
-
A 24-year-old female visits her family physician to complain of painless lumps in her neck. Her physician notes several enlarged, rubbery, non-tender cervical lymph nodes on examination. He immediately refers the patient for a lymph node biopsy, the results of which show the presence of Reed-Sternberg cells.
What is the diagnosis in this case based on the above scenario?Your Answer:
Correct Answer: Hodgkin’s lymphoma
Explanation:The presence of Reed-Sternberg cells is pathognomonic for Hodgkin’s Lymphoma, which is a disease-causing neoplastic transformation of lymphocytes. There is a bimodal age distribution with peaks in the 20s and 60s. Patients typically present with enlarged, rubbery, non-tender lymph nodes. Symptoms such as fever, night sweats and weight loss may be present.
Pain after alcohol consumption is a pathognomonic sign of Hodgkin’s lymphoma, it is, however, not a ‘B’ symptom. It is rare though, only occurring in 2-3% of patients with Hodgkin’s lymphoma.
The Ann Arbour clinical staging is as follows:
Stage I: one involved lymph node group
Stage II two involved lymph node groups on one side of the diaphragm
Stage III: lymph node groups involved on both sides of the diaphragm
Stage IV: Involvement of extra-nodal tissues, such as the liver or bone marrow
Diagnosis is made by lymph node biopsy, which should be taken from a sufficiently large specimen or excisional biopsy, as opposed to a fine needle biopsy.Multiple myeloma most commonly presents with bone pain, especially in the back and ribs.
In non-Hodgkin’s lymphoma, Reed-Sternberg cells are not present.
Acute lymphoblastic leukaemia will present with features of anaemia, thrombocytopenia and leukopenia.
The most common symptoms of chronic lymphocytic leukaemia are fatigue, night sweats and low-grade fever.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 82
Incorrect
-
You assess a patient that has suffered a nerve injury that has paralysed her left latissimus dorsi muscle.
Latissimus dorsi receives its innervation from which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Thoracodorsal nerve
Explanation:Latissimus dorsi originates from the lower part of the back, where it covers a wide area. It lies underneath the inferior fibres of trapezius superiorly, and trapezius is the most superficial back muscle.
Superficial muscles of the back showing latissimus dorsi (from Gray’s Anatomy)
Latissimus dorsi has a broad origin, arising from the spinous processes of T6-T12, the thoracolumbar fascia, the iliac crest and the inferior 3 or 4 ribs. The fibres converge into a tendon that inserts into the intertubercular groove of the humerus.
Latissimus dorsi is innervated by the thoracodorsal nerve.
Latissimus dorsi acts to extend, adduct and medially rotate the humerus. It, therefore, raises the body towards the arm during climbing. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 83
Incorrect
-
A 2-day-old male is referred to a tertiary care hospital by the community midwife after a home visit due to jaundice and dyspnoea. After history and examination, the relevant blood work is performed, and the baby is found to have conjugated hyperbilirubinemia. The paediatric team suspects a hepatic origin for jaundice based on the findings.
Which one of the following aetiologies is the most likely cause of jaundice in this case?Your Answer:
Correct Answer: Alpha 1-antitrypsin deficiency
Explanation:The presence of dyspnoea makes alpha-1 antitrypsin deficiency the more likely diagnosis as biliary atresia does not cause respiratory symptoms. Deficiency of the enzyme alpha-1 antitrypsin causes uninhibited elastase activity and a decrease in elastic tissue. This causes liver cirrhosis leading to an elevation of conjugated bilirubin and emphysema in the lungs.
Rhesus disease, hereditary spherocytosis and breast milk jaundice cause an elevation of unconjugated bilirubin thus ruling it out in this case. Breast milk jaundice occurs due to an inability of the newborn to metabolize the proteins in breast milk.
Rhesus disease occurs when an Rh negative mother gives birth to an Rh positive baby. The jaundice would have been accompanied by anaemia and oedema.
Hereditary spherocytosis occurs due to extravascular haemolysis as defective RBCs are removed by the spleen. The patient would present with jaundice, splenomegaly and possibly an aplastic crisis (if Parvovirus B19 infection).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 84
Incorrect
-
One of the benefits of wound healing through first intention is:
Your Answer:
Correct Answer: Minimisation of scar tissue formation
Explanation:Primary wound healing, or healing by first intention, occurs within hours of repairing a full-thickness surgical incision. This surgical insult results in the mortality of a minimal number of cellular constituents. Healing by first intention can occur when the wound edges are opposed, the wound is clean and uninfected and there is minimal loss of cells and tissue i.e. surgical incision wound. The wound margins are joined by fibrin deposition, which is subsequently replaced by collagen and covered by epidermal growth.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 85
Incorrect
-
You review the arterial blood gas (ABG) of a patient with lactic acidosis.
Which SINGLE statement regarding lactic acidosis is true?Your Answer:
Correct Answer: Type A lactic acidosis is typically due to tissue hypoxia
Explanation:Lactic acidosis is defined as a pH <7.35 and a lactate >5 mmol/L. It is a common finding in critically ill patients and is often associated with other serious underlying pathologies. The anion gap is raised in lactic acidosis.
There are major adverse consequences of severe acidaemia, which affect all body systems, and there is an associated increase in mortality of critically ill patients with a raised lactate. The mortality associated with lactic acidosis despite full supportive treatment remains at 60-90%.
Acquired lactic acidosis is classified into two subtypes:
Type A is due to tissue hypoxia
Type B is due to non-hypoxic processes affecting the production and elimination of lactate
Lactic acidosis can be extreme after a seizure but usually resolves spontaneously within a few hours.
Left ventricular failure typically results in tissue hypoperfusion and a type A lactic acidosis.
Some causes of type A and type B lactic acidosis are shown below:
Type A lactic acidosis
Type B lactic acidosis
Shock (including septic shock)
Left ventricular failure
Severe anaemia
Asphyxia
Cardiac arrest
CO poisoning
Respiratory failure
Severe asthma and COPD
Regional hypoperfusion
Renal failure
Liver failure
Sepsis (non-hypoxic sepsis)
Thiamine deficiency
Alcoholic ketoacidosis
Diabetic ketoacidosis
Cyanide poisoning
Methanol poisoning
Biguanide poisoning -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 86
Incorrect
-
A 58-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.
Which of the following is the patient's preferred drug treatment?Your Answer:
Correct Answer: Nicardipine
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.
Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.
The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.
An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 87
Incorrect
-
A blood culture was performed from a sample taken from a patient. It was noted that a Gram-negative coccus organism was grown.
Among the following microorganisms, which is considered an example of a Gram-negative coccus?Your Answer:
Correct Answer: Neisseria menigitidis
Explanation:Staphylococcus aureus = Gram-positive coccus
Bacillus cereus = Gram-positive bacillus
Campylobacter jejuni = Gram-negative bacillus
Escherichia coli = Gram-negative bacillusIn Gram staining, crystal violet is a purple stain that is used to stain the bacteria first. The stained bacteria are decolorized and then stained with a red stain, which is safranin. Bacteria with thick cell walls keep the purple stain and are called Gram-positive. Thin-walled bacteria are easily decolorized so when safranin, the red stain, is placed on the organisms, they become red or Gram-negative.
Neisseria species appear as Gram-negative diplococci because they form pairs and their adjacent ends are flattened that is why they are also described to have a coffee-bean or kidney-bean shape. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 88
Incorrect
-
Swelling of the lips, tongue, and face is observed in a 59-year-old African-American woman. In the emergency room, she is given intramuscular adrenaline, but her symptoms do not improve. Her GP recently started her on a new medication.
Which of the following drugs is most likely to have caused her symptoms?Your Answer:
Correct Answer: Ramipril
Explanation:Angiotensin-converting enzyme (ACE) inhibitors are the most common cause of drug-induced angioedema in the United Kingdom and the United States, owing to their widespread use.
Angioedema is caused by ACE inhibitors in 0.1 to 0.7 percent of patients, with data indicating a persistent and relatively constant risk year after year. People of African descent have a five-fold higher chance of contracting the disease.
Swelling of the lips, tongue, or face is the most common symptom, but another symptom is episodic abdominal pain due to intestinal angioedema. Itching and urticaria are noticeably absent.
The mechanism appears to be activated complement or other pro-inflammatory cytokines like prostaglandins and histamine, which cause rapid vasodilation and oedema.
Other medications that are less frequently linked to angioedema include:
Angiotensin-receptor blockers (ARBs)
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Bupropion (e.g. Zyban and Wellbutrin)
Beta-lactam antibiotics
Statins
Proton pump inhibitorsThe majority of these reactions are minor and can be treated by stopping the drug and prescribing antihistamines.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 89
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.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 90
Incorrect
-
In a 7-year-old child with chickenpox, which of the following would you advise the mother NOT to do?
Your Answer:
Correct Answer: Give ibuprofen for the fever
Explanation:Chickenpox (varicella zoster) is a highly contagious airborne disease and has an incubation period of between 7-21 days. It often has a prodromal phase when there is a fever, aches and headaches, dry cough, and sore throat before onset of rash.
Some recognized complications of chickenpox are:
Orchitis
Hepatitis
Pneumonia
Encephalitis
Infected spots
Otitis media
Myocarditis
Glomerulonephritis
Appendicitis
PancreatitisTreatment is symptomatic and includes using paracetamol to manage fever. There is a link between use of ibuprofen in patients with chicken-pox and necrotizing fasciitis so Ibuprofen should NOT be used.
An emollient and antihistamine can be used to ease the itchy rash and oral hydration is encouraged.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 91
Incorrect
-
Which of the following statements is correct with regards to Hodgkin's lymphoma?
Your Answer:
Correct Answer: Most patients present with painless asymmetrical lymphadenopathy, with cervical nodes involved most commonly.
Explanation:Lymphoma is a cancer of the lymphatic system, which is part of the body’s germ-fighting network. They are a group of diseases that are caused by malignant lymphocytes. These malignant cells accumulate in lymph nodes and other lymphoid tissue, giving rise to the characteristic clinical feature of lymphadenopathy.
They can be subdivided into Hodgkin lymphoma (HL) which are characterised by the presence of Reed-Sternberg cells, and non-Hodgkin lymphoma (NHL).
Characteristics of HL include:
1. can present at any age but is rare in children and has a peak incidence in young adults,
2. almost 2:1 male predominance.
3. presents with painless, asymmetrical, firm and discrete enlargement of superficial lymph nodes.
4. cervical node involvement in 60-70% of cases,
5. axillary node involvement in 10-15%
6. inguinal node involvement in 6-12%.
7. modest splenomegaly during the course of the disease in 50% of patients
8. may occasionally have liver enlargement
9. bone marrow failure involvement is unusual in early disease.
Approximately 85% of patients are cured, but the prognosis depends on age, stage and histology.
Two well‐known but rare symptoms in HL are alcohol‐induced pain and pruritus. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 92
Incorrect
-
Identify the type of graph described below:
This graph has been used to create visual representations to communicate the risks and benefits of treatments using 4 face categories.Your Answer:
Correct Answer: Cates plot
Explanation:Cates Plot, since 1999, has been used to create visual representations to communicate the risks and benefits of treatments. The essence of Cates Plot is the use of 4 face categories to visually indicate the following:
People not affected by a treatment (green faces for those with a good outcome and red for those with a bad outcome)
People for which treatment changes their category from a bad outcome to a good outcome (yellow faces)
People for which treatment causes an adverse event and changes their category from a good outcome to a bad outcome (crossed out green faces) -
This question is part of the following fields:
- Evidence Based Medicine
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Question 93
Incorrect
-
An ambulance transports a 72-year-old woman to the Emergency Department. She is confused, has been vomiting and having stomach pains. Digoxin is one of her medications.
Which of the following claims about digoxin is correct?Your Answer:
Correct Answer: Therapeutic plasma levels are between 1.0-1.5 nmol/l
Explanation:Digoxin is a cardiac glycoside that is used to treat atrial fibrillation and flutter, as well as congestive heart failure. In cardiac myocytes, it works by inhibiting the membrane Na/K ATPase. Through Na/Ca exchange, this raises intracellular sodium concentration and indirectly increases intracellular calcium availability. Increased intracellular calcium levels have both a positive inotropic and negative chronotropic effect.
Digoxin therapeutic plasma levels are typically between 1.0 and 1.5 nmol/l, though higher concentrations may be required, and the value varies between laboratories. At concentrations greater than 2 nmol/l, the risk of toxicity increases dramatically.
In patients with normal renal function, digoxin has a long plasma half-life of 36 to 48 hours. This can take up to 5 days in patients with impaired renal function.
Hypokalaemia, rather than hyperkalaemia, has been shown to increase the risk of digoxin toxicity.
In the treatment of persistent and permanent atrial fibrillation, digoxin is no longer widely used. Beta-blockers, also known as rate-limiting calcium channel blockers, are now the first-line treatment for this condition.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 94
Incorrect
-
Regarding the lumbar plexus, which of the following is a direct muscular branch?
Your Answer:
Correct Answer: Nerve to quadratus lumborum
Explanation:The lumbar plexus gives rise to several branches which supply various muscles and regions of the posterior abdominal wall and lower limb. These branches include the Iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral and obturator nerves.
In addition, the lumbar plexus gives off muscular branches from its roots, a branch to the lumbosacral trunk and occasionally an accessory obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 95
Incorrect
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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
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Question 96
Incorrect
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A patient presents with increased breathlessness and worsening of his chronic cough and. He has a chronic lung disorder and is on long-term oxygen therapy (LTOT). Which of these is an indication for LTOT?
Your Answer:
Correct Answer: A non-smoker with COPD and a PaO2 of 7.5 kPa when stable with secondary polycythaemia
Explanation:Long-term administration of oxygen, usually at least 15 hours daily, improves survival in COPD patients who have severe hypoxaemia.
Long-term oxygen therapy should be considered in:
A non-smoker with COPD and a PaO2<7.3 kPa when stable
A non-smoker with COPD and PaO27.3–8 kPa when stable and with secondary polycythaemia, peripheral oedema, or evidence of pulmonary hypertension
Severe chronic asthma with PaO2<7.3 kPa or persistent disabling breathlessness
A patient with Interstitial lung disease with PaO2<8 kPa and in patients with PaO2>8 kPa with disabling dyspnoea
A patient with cystic fibrosis when PaO2<7.3 kPa or if PaO27.3–8 kPa in the presence of secondary polycythaemia, nocturnal hypoxaemia, pulmonary hypertension, or peripheral oedema
Pulmonary hypertension, without parenchymal lung involvement when PaO2<8 kPa
Neuromuscular or skeletal disorders, after specialist assessment
Obstructive sleep apnoea despite continuous positive airways pressure therapy, after specialist assessment
Pulmonary malignancy or other terminal disease with disabling dyspnoea
Heart failure with daytime PaO2<7.3 kPa when breathing air or with nocturnal hypoxaemia
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 97
Incorrect
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A patient with diplopia is found to have eye deviation downwards and outwards. The likely nerves that are affected are:
Your Answer:
Correct Answer: Oculomotor nerve
Explanation:The results of an oculomotor (CN III) nerve palsy are a depressed and abducted (down and out) eye, ptosis, diplopia, and a fixed and dilated pupil.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 98
Incorrect
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A tumour compresses the jugular foramen of a 50-year-old patient. Compression of several nerves in the jugular foramen will result in which of the following complications?
Your Answer:
Correct Answer: Loss of gag reflex
Explanation:The glossopharyngeal nerve, which is responsible for the afferent pathway of the gag reflex, the vagus nerve, which is responsible for the efferent pathway of the gag reflex, and the spinal accessory nerve all exit the skull through the jugular foramen. These nerves are most frequently affected if the jugular foramen is compressed. As a result, the patient’s gag reflex is impaired.
The vestibulocochlear nerve is primarily responsible for hearing. The trigeminal nerve provides sensation in the face. The facial nerve innervates the muscles of face expression (including those responsible for closing the eye). Tongue motions are controlled mostly by the hypoglossal nerve.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 99
Incorrect
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A 34-year-old woman was diagnosed with multiple sclerosis two years ago. Her symptoms have been steadily deteriorating, with no intervals of remission in sight.
Which of the following aspects of nerve conduction is disrupted by multiple sclerosis?
Your Answer:
Correct Answer: Saltatory conduction
Explanation:Local currents propagate action potentials down the axons of neurons. This local current flow following depolarisation results in the depolarisation of the neighbouring axonal membrane, and when this region approaches the threshold, more action potentials are generated and so forth. Due to the refractory period, portions of the membrane that have recently depolarized will not depolarize again, resulting in the action potential only being able to go in one direction.
The square root of axonal diameter determines the velocity of the action potential; the axons with the biggest diameter have the quickest conduction velocities. When a neuron is myelinated, the speed of the action potential rises as well.
The myelin sheath is an insulating coating that surrounds certain neural axons. By increasing membrane resistance and decreasing membrane capacitance, the myelin sheath improves conduction. This enables faster electrical signal transmission via a neuron, making them more energy-efficient than non-myelinated neuronal axons.
Electrical impulses are quickly transmitted from one node to the next, causing depolarization of the membrane above the threshold and triggering another action potential, which is then transmitted to the next node. An action potential is rapidly conducted down a neuron in this manner. Saltatory conduction is the term for this.
Multiple sclerosis is an example of a clinical disorder in which the myelin sheath is affected. It is an immune-mediated disorder in which certain nerve cells in the brain and spinal cord become demyelinated. The ability of some areas of the nervous system to properly transmit action potentials is disrupted by demyelination, resulting in a variety of neurological symptoms and indications. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 100
Incorrect
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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.
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This question is part of the following fields:
- Anatomy
- Thorax
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SESSION STATS - PERFORMANCE PER SPECIALTY
