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Question 1
Correct
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Question 2
Correct
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Which of the following is NOT a typical clinical feature of diabetic ketoacidosis:
Your Answer: Cheyne–Stokes respiration
Explanation:Clinical features of DKA:
Symptoms: Polyuria, polydipsia, thirst, lethargy, weight loss, nausea, vomiting, anorexia, abdominal pain, dehydration, headache, altered mental state
Signs: Dry mucous membranes, ketotic breath, tachycardia, hypotension, Kussmaul breathing, focal signs of precipitant e.g. infection -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 3
Correct
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An analytical cohort study is done to compare the relationship between omega 3 intake and occurrence of myocardial infarction (MI) among males aged over 65 years. The following are the data from the study:
No. of subjects taking placebo: 100 men
No. of subjects taking placebo who suffered an MI: 15 men
No. of subjects taking omega 3: 100 men
No. of subjects taking omega 3 who suffered an MI: 5 men
Compute for the absolute risk in the treatment (omega 3) group.Your Answer: 0.05
Explanation:The absolute risk (AR) is the probability or chance of an event. It is computed as the number of events in treated or control groups, divided by the number of people in that group.
AR = 5/100 = 0.05
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This question is part of the following fields:
- Evidence Based Medicine
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Question 4
Correct
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What is the earliest physiological effect that causes postural hypotension:
Your Answer: A fall in central venous pressure
Explanation:When autonomic reflexes are impaired or intravascular volume is markedly depleted, a significant reduction in blood pressure occurs upon standing, a phenomenon termed Postural Hypotension (orthostatic hypotension). Orthostatic hypotension can cause dizziness, syncope, and even angina or stroke. When autonomic reflexes are impaired, blood pressure falls progressively after standing because the gravitational pooling of blood in the legs cannot be compensated by sympathetic vasoconstriction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 5
Correct
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Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 6
Correct
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A 33-year-old female, who recently returned from a trip to Bangladesh, presents to the infectious diseases clinic with complaints of productive cough with blood-stained sputum, night sweats, and weight loss for the past one month. Based on the history and examination findings, you suspect pulmonary tuberculosis.
Which ONE of the following investigations is most appropriate to make a diagnosis of active tuberculosis?Your Answer: Sputum for acid-fast bacilli smear
Explanation:Multiple investigations may be done to establish a diagnosis of active tuberculosis. In this case, sputum for acid-fast bacilli would be the best option as it can be done immediately, give fast results, and promptly initiate treatment. Three-morning sputum samples are collected and tested for acid-fast bacilli using gram staining.
Blood culture would yield results in tuberculous bacteraemia and would be less sensitive than sputum testing.
A chest X-ray would not differentiate active tuberculosis from an old infection in which the Ghon complex has formed, and the body’s immune reaction contains the Mycobacterium tuberculosis bacteria.
Mantoux test shows the presence of antibodies to tuberculosis and may be positive if the patient has had a previous infection or been vaccinated against tuberculosis.
A CT chest would also be unable to differentiate between an active infection and the findings of old tuberculosis infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 7
Correct
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What is the average healing time for a femoral shaft fracture under normal circumstances? Choose ONE answer.
Your 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 8
Correct
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A 28-year-old female arrives after taking an unknown chemical in excess. She is tired and her speech is slurred. The following are her observations and results:HR 118,BP 92/58,SaO2 96%
HR 118, 11/15 The following are the results of his arterial blood gas (ABG):
pH: 7.24pO 2 : 9.4kPa PCO2 : 3.3kPa HCO 3 -: 22 mmol/lNa + : 143 mmol/lCl – : 99 mmol/lLactate: 5 IU/l
Which of the following statements about this patient is TRUE?Your Answer: Her anion gap is elevated
Explanation:The interpretation of arterial blood gas (ABG) aids in the measurement of a patient’s pulmonary gas exchange and acid-base balance.
The normal values on an ABG vary a little depending on the analyser, but they are roughly as follows:
Variable
Range
pH
7.35 – 7.45
PaO2
10 – 14 kPa
PaCO2
4.5 – 6 kPa
HCO3-
22 – 26 mmol/l
Base excess
-2 – 2 mmol/lThe patient’s history indicates that she has taken an overdose in this case. Because her GCS is 11/15 and she can communicate with slurred speech, she is clearly managing her own airway, there is no current justification for intubation.
The following are the relevant ABG findings:
Hypoxia (mild)
pH has been lowered (acidaemia)
PCO2 levels are low.
bicarbonate in its natural state
Lactate levels have increasedThe anion gap represents the concentration of all the unmeasured anions in the plasma. It is the difference between the primary measured cations and the primary measured anions in the serum. It can be calculated using the following formula:
Anion gap = [Na+] – [Cl-] – [HCO3-]The reference range varies depending on the technique of measurement, but it is usually between 8 and 16 mmol/L.
The following formula can be used to compute her anion gap:
Anion gap = [143] – [99] – [22]
Anion gap = 22As a result, it is clear that she has a metabolic acidosis with an increased anion gap.
The following are some of the causes of type A and type B lactic acidosis:
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 9
Correct
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Which of the following is NOT a common clinical manifestation of sickle cell disease?
Your Answer: Iron deficiency
Explanation:Signs and symptoms of Sickle cell disease(SCD):
Acute and chronic pain: The most common clinical manifestation of SCD is vaso-occlusive crisis; pain crises are the most distinguishing clinical feature of SCD
Bone pain: Often seen in long bones of extremities, primarily due to bone marrow infarction
Anaemia: Universally present, chronic, and haemolytic in nature
Aplastic crisis: Serious complication due to infection with parvovirus B19 (B19V)
Splenic sequestration: Characterized by the onset of life-threatening anaemia with rapid enlargement of the spleen and high reticulocyte count
Infection: Organisms that pose the greatest danger include encapsulated respiratory bacteria, particularly Streptococcus pneumoniae; adult infections are predominantly with gram-negative organisms, especially Salmonella
Growth retardation, delayed sexual maturation, being underweight
Hand-foot syndrome: This is a dactylitis presenting as bilateral painful and swollen hands and/or feet in children
Acute chest syndrome: Young children present with chest pain, fever, cough, tachypnoea, leucocytosis, and pulmonary infiltrates in the upper lobes; adults are usually afebrile, dyspnoeic with severe chest pain, with multilobar/lower lobe disease
Pulmonary hypertension: Increasingly recognized as a serious complication of SCD
Avascular necrosis of the femoral or humeral head: Due to vascular occlusion
Central nervous system (CNS) involvement: Most severe manifestation is stroke
Ophthalmologic involvement: Ptosis, retinal vascular changes, proliferative retinitis
Cardiac involvement: Dilation of both ventricles and the left atrium
Gastrointestinal involvement: Cholelithiasis is common in children; liver may become involved
Genitourinary involvement: Kidneys lose concentrating capacity; priapism is a well-recognized complication of SCD
Dermatologic involvement: Leg ulcers are a chronic painful problem -
This question is part of the following fields:
- Haematology
- Pathology
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Question 10
Correct
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Blood flows from the left atrium into the left ventricle via:
Your Answer: The mitral valve
Explanation:Blood flows from the right atrium into the right ventricle via the tricuspid atrioventricular valve and from the left atrium into the left ventricle via the mitral atrioventricular valve. Blood is ejected from the right ventricle through the pulmonary semilunar valve into the pulmonary artery and from the left ventricle via the aortic semilunar valve into the aorta.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 11
Incorrect
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A 76-year-old man presents with complaints of double vision. Upon physical examination, it was observed that he exhibits left-sided hemiplegia and left-sided loss of joint position sense, vibratory sense and discriminatory touch. In addition, he has the inability to abduct his right eye and is holding his head towards the right side. A CT scan was ordered and showed that he has suffered a right-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer: Inferior cerebellar artery
Correct Answer: Basilar artery
Explanation:Inferior medial pontine syndrome, also known as Foville syndrome, is one of the brainstem stroke syndromes which occurs when there is infarction of the medial inferior aspect of the pons due to occlusion of the paramedian branches of the basilar artery.
It is characterized by ipsilateral sixth nerve palsy, facial palsy, contralateral hemiparesis, contralateral loss of proprioception and vibration, ipsilateral ataxia, ipsilateral facial weakness, and lateral gaze paralysis and diplopia.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 12
Correct
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A patient suffers a lower limb fracture that causes damage to the nerve that innervates peroneus brevis.
Peroneus brevis receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Superficial 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 13
Correct
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Your consultant requests that you do a lumbar puncture on a patient who is suspected of having meningitis. This patient, a 15-year-old female, presented to the emergency department with a fever, headache, and neck stiffness. Where should you aspirate a sample of CSF?
Your Answer: Subarachnoid space
Explanation:A lumbar puncture, also known as a spinal tap, is a procedure that involves inserting a needle into the lower back’s lumbar region.
A needle is inserted into the space between the arachnoid mater and the pia mater, also known as the subarachnoid space, to remove a sample of cerebrospinal fluid.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 14
Correct
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Which of the following side effects is more common of etomidate than other intravenous induction agents:
Your Answer: Extraneous muscle movements
Explanation:Etomidate is associated with a high incidence of extraneous muscle movements, which can be minimised by an opioid analgesic or a short-acting benzodiazepine given prior to induction. Etomidate causes less hypotension than thiopental sodium and propofol during induction. Etomidate is associated with rapid recovery without a hangover effect. The rate of respiratory depression and tachycardia is not higher in etomidate.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 15
Correct
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 16
Correct
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Which of the following cervical nerves is likely to be affected if your patient is complaining of elbow extension weakness and loss of sensation in her middle finger? She also has pain and tenderness in her cervical region, which is caused by a herniated disc, all after a whiplash-type injury in a car accident.
Your Answer: C7
Explanation:A C7 spinal nerve controls elbow extension and some finger extension.
Damage to this nerve can result in a burning pain in the shoulder blade or back of the arms. The ability to extend shoulders, arms, and fingers may also be affected. Dexterity may also be compromised in the hands or fingers.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 17
Incorrect
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An ambulance transports a 40-year-old man to the hospital. He ingested a significant amount of aspirin.
In the early stages of an aspirin overdose, which form of acid-base problem should you anticipate?Your Answer: Respiratory acidosis
Correct Answer: Respiratory alkalosis
Explanation:When you take too much aspirin, you have a mix of respiratory alkalosis and metabolic acidosis. Respiratory centre stimulation produces hyperventilation and respiratory alkalosis in the early phases. The direct acid actions of aspirin tend to create a higher anion gap metabolic acidosis in the latter phases.
Below summarizes some of the most common reasons of acid-base abnormalities:Respiratory alkalosis:
– Hyperventilation (e.g. anxiety, pain, fever)
– Pulmonary embolism
– Pneumothorax
– CNS disorders (e.g. CVA, SAH, encephalitis)
– High altitude
– Pregnancy
– Early stages of aspirin overdoseRespiratory acidosis:
– COPD
– Life-threatening asthma
– Pulmonary oedema
– Respiratory depression (e.g. opiates, benzodiazepines)
– Neuromuscular disease (e.g. Guillain-Barré syndrome, muscular dystrophy
– Incorrect ventilator settings (hypoventilation)
– ObesityMetabolic alkalosis:
– Vomiting
– Cardiac arrest
– Multi-organ failure
– Cystic fibrosis
– Potassium depletion (e.g. diuretic usage)
– Cushing’s syndrome
– Conn’s syndromeMetabolic acidosis (with raised anion gap):
– Lactic acidosis (e.g. hypoxaemia, shock, sepsis, infarction)
– Ketoacidosis (e.g. diabetes, starvation, alcohol excess)
– Renal failure
– Poisoning (e.g. late stages of aspirin overdose, methanol, ethylene glycol)Metabolic acidosis (with normal anion gap):
– Renal tubular acidosis
– Diarrhoea
– Ammonium chloride ingestion
– Adrenal insufficiency -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 18
Correct
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During anaerobic respiration, what is the net generation of ATP molecules:
Your 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 19
Incorrect
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A patient allergic to penicillin and with marked cellulitis presents and you decide to start him on erythromycin.
Which statement about macrolide antibiotics is true?
Your Answer: They are bactericidal
Correct Answer: They are actively concentrated within leukocytes
Explanation:Macrolide antibiotics are bacteriostatic.
They act by binding to the 50S subunit of the bacterial ribosome inhibit protein synthesis.
Macrolide antibiotics are actively concentrated within leukocytes, because of this, they are transported into the site of infection.
Macrolide antibiotics are not effective in meningitis as they do not penetrate the central nervous system well.
They are mainly against Gram-positive organisms and can be used as an alternative in patients with penicillin allergy.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 20
Correct
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You review the arterial blood gas (ABG) of a patient with lactic acidosis.
Which SINGLE statement regarding lactic acidosis is true?Your 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 BÂ 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 21
Incorrect
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Which of the following does NOT affect the rate of flow of a liquid through a tube:
Your Answer: Pressure differences across the ends of the tube
Correct Answer: Surface tension
Explanation:Flow through a tube is dependent upon:
The pressure difference across the ends of the tube (P1– P2)
The resistance to flow provided by the tube (R)
This is Darcy’s law, which is analogous to Ohm’s law in electronics:
Flow = (P1– P2) / R
Resistance in the tube is defined by Poiseuille’s law, which is determined by the diameter of the tube and the viscosity of the fluid. Poiseuille’s law is as follows:
Resistance = (8VL) / (Ï€R4)
Where:
V = The viscosity of the fluid
L = The length of the tube
R = The radius of the tube
Therefore, in simple terms, resistance is directly proportional to the viscosity of the fluid and the length of the tube and inversely proportional to the radius of the tube. Of these three factors, the most important quantitatively and physiologically is vessel radius.
It can be seen that small changes in the radius can have a dramatic effect on the flow of the fluid. For example, the constriction of an artery by 20% will decrease the flow by approximately 60%.
Another important and frequently quoted example of this inverse relationship is that of the radius of an intravenous cannula. Doubling the diameter of a cannula increases the flow rate by 16-fold (r4). This is the reason the diameter of an intravenous cannula in resuscitation scenarios is so important.
*Please note that knowledge of the detail of Poiseuille’s law is not a requirement of the RCEM Basic Sciences Curriculum. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 22
Incorrect
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Which of these immunoglobulin molecules can cross the placenta?
Your Answer: IgA
Correct Answer: IgG
Explanation:An important mechanism that provides protection to the foetus is placental transfer of maternal IgG antibodies while his/her humoral response is inefficient. The only antibody class that significantly crosses the human placenta is IgG.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 23
Correct
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Which of the following virulence factors of E. coli is important for attachment to host epithelial cells in the pathogenesis of urinary tract infections:
Your Answer: Pili
Explanation:Escherichia coli is the most common cause of urinary tract infection. Uropathic strains are characterised by pili with adhesion proteins that bind to specific receptors on the urinary tract epithelium. The motility of E. coli aids its ability to ascend the urethra into the bladder or ascend the ureter into the kidney.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 24
Incorrect
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Regarding the lumbar plexus, which of the following is a direct muscular branch?
Your Answer: Nerve to piriformis
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 25
Correct
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Regarding dynamic compression of the airways, which of the following statements is CORRECT:
Your Answer: It occurs during forced expiration.
Explanation:Dynamic compression occurs because as the expiratory muscles contract during forced expiration, all the structures within the lungs, including the airways, are compressed by the positive intrapleural pressure. Consequently the smaller airways collapse before the alveoli empty completely and some air remains within the lungs (the residual volume). Physiologically this is important as a completely deflated lung with collapsed alveoli requires significantly more energy to inflate. Dynamic compression does not occur in normal expiration because the intrapleural pressure is negative throughout the whole cycle.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 26
Incorrect
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A 54-year-old woman presents with polyuria and polydipsia. She is known to suffer from bipolar disorder, which has been well controlled by the use of lithium for many years.
What is the SINGLE most likely diagnosis?Your Answer: Psychogenic polydipsia
Correct Answer: Nephrogenic diabetes insipidus
Explanation:Diabetes insipidus is the inability to produce concentrated urine. It is characterised by the presence of excessive thirst, polyuria and polydipsia. There are two distinct types of diabetes insipidus:
Cranial (central) diabetes insipidus and;
Nephrogenic diabetes insipidus
Cranial diabetes insipidus is caused by a deficiency of vasopressin (anti-diuretic hormone). Patients with cranial diabetes insipidus can have a urine output as high as 10-15 litres per 24 hours, but adequate fluid intake allows most patients to maintain normonatraemia. 30% of cases are idiopathic, and a further 30% are secondary to head injuries. Other causes include neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis) and drugs, such as naloxone and phenytoin. A very rare inherited form also exists that is associated with diabetes mellitus, optic atrophy, nerve deafness and bladder atonia.
Nephrogenic diabetes insipidus is caused by renal resistance to the action of vasopressin. As with cranial diabetes insipidus, urine output is markedly elevated. Serum sodium levels can be maintained by secondary polydipsia or can be elevated. Causes of nephrogenic diabetes insipidus include chronic renal disease, metabolic disorders (e.g. hypercalcaemia and hypokalaemia) and drugs, including long-term lithium usage and demeclocycline.
In view of the history of long-term lithium use, in this case, nephrogenic diabetes insipidus is the most likely diagnosis. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 27
Correct
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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 most superficial structure injured in the case above?Your Answer: Camper’s fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:
Skin
Fatty layer of the superficial fascia (Camper’s fascia)
Membranous layer of the superficial fascia (Scarpa’s fascia)
Aponeurosis of the external and internal oblique muscles
Rectus abdominis muscle
Aponeurosis of the internal oblique and transversus abdominis
Fascia transversalis
Extraperitoneal fat
Parietal peritoneum -
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 28
Correct
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Regarding ampicillin, which of the following statements is CORRECT:
Your 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 29
Incorrect
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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: Long thoracic nerve
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 30
Correct
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Regarding the accessory nerve, which of the following statements is INCORRECT:
Your Answer: Accessory nerve palsy results in the inability to nod the head
Explanation:Accessory nerve palsy results in inability to shrug the shoulders and to rotate the head to look at the opposite side to the lesion.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 31
Correct
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Parathyroid hormone is released by which of the following:
Your Answer: Chief cells of the parathyroid gland
Explanation:Parathyroid hormone (PTH) is a peptide hormone synthesised by the chief cells of the parathyroid glands, located immediately behind the thyroid gland. PTH is primarily released in response to decreasing plasma [Ca2+] concentration. PTH acts to increase plasma calcium levels and decrease plasma phosphate levels.
Parathyroid hormone (PTH) acts to increase calcium reabsorption in the distal tubule of the nephron (by activating Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane) and increase phosphate excretion by inhibiting reabsorption in the proximal tubule of the nephron. -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 32
Incorrect
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The following are all examples of type II hypersensitivity EXCEPT for:
Your Answer: Incompatible blood transfusions
Correct Answer: Post-streptococcal glomerulonephritis
Explanation:Examples of type II reactions include:
Incompatible blood transfusions
Haemolytic disease of the newborn
Autoimmune haemolytic anaemias
Goodpasture’s syndrome
Rheumatic heart disease
Bullous pemphigoid -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 33
Correct
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Which of these is NOT a naturally occurring anticoagulant:
Your Answer: Factor V Leiden
Explanation:It’s crucial that thrombin’s impact is restricted to the injured site. Tissue factor pathway inhibitor (TFPI), which is produced by endothelial cells and found in plasma and platelets, is the first inhibitor to function. It accumulates near the site of harm induced by local platelet activation. Xa and VIIa, as well as tissue factor, are inhibited by TFPI. Other circulating inhibitors, the most potent of which is antithrombin, can also inactivate thrombin and other protease factors directly. Coagulation cofactors V and VIII are inhibited by protein C and protein S. Tissue plasminogen activator (TPA) from endothelial cells facilitates fibrinolysis by promoting the conversion of plasminogen to plasmin.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 34
Incorrect
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Regarding Clostridium difficile, which of the following statements is CORRECT:
Your Answer: It has endotoxin-mediated effects causing profuse watery diarrhoea.
Correct Answer: It is normally found in gut flora.
Explanation:C. difficile is normally found in the gut flora but its growth is normally suppressed by more dominant anaerobes. It has exotoxin-mediated effects causing profuse diarrhoea. Oral clindamycin (a broad spectrum antibiotic) is commonly implicated in precipitating C. difficile colitis; first line treatment is with oral metronidazole. Tetanolysin is a toxin produced by Clostridium tetani bacteria.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 35
Correct
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Herpes simplex virus is transmitted most commonly through which of the following routes:
Your Answer: Direct contact spread
Explanation:Herpes simplex virus is the most common cause of infective encephalitis and has a predilection for the temporal lobes. Herpes simplex is transmitted through direct contact. It invades skin locally producing skin vesicles by its cytolytic activity.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 36
Correct
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Regarding red blood cell group antigens and antibodies, which of the following statements is CORRECT:
Your Answer: Anti-D antibodies are usually IgG.
Explanation:Approximately 400 red blood cell group antigens have been described. The ABO group antigens are unusual in that naturally occurring antibodies occur in the plasma of subjects who lack the corresponding antigen, even if they have not been exposed to that antigen previously. The most important of these natural antibodies are anti-A and anti-B, which are usually IgM. Anti-D antibodies don’t occur naturally, and are therefore immune antibodies that result from previous transfusions or pregnancy. Only IgG antibodies are capable of transplacental passage and the most important immune antibody is the Rh antibody, anti-D.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 37
Correct
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A 22-year-old presents with acute severe asthma. He takes a drug prescribed by her GP but cannot recall the name and is receiving regular salbutamol nebulisers. His current potassium level is 2.8 mmol/l.
Which drug is least likely to have caused his hypokalaemia?
Your Answer: Spironolactone
Explanation:Serious hypokalaemia can occur in severe asthma and the effect can be potentiated by concomitant treatment with theophyllines like aminophylline, corticosteroids, thiazide and loop diuretics, and hypoxia. Plasma-potassium concentration should be monitored in severe asthma.
Spironolactone, a potassium-sparing diuretic, is not likely to have contributed to patients hypokalaemia.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 38
Correct
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Regarding bile, which of the following statements is CORRECT:
Your Answer: Bile passes into the duodenum through the ampulla of Vater.
Explanation:Bile is synthesised in the liver. Bile functions to eliminate endogenous and exogenous substances from the liver, to neutralise gastric acid in the small intestine, and to emulsify fats in the small intestine and facilitate their digestion and absorption. Bile is stored and concentrated in the gallbladder. Bile passes out of the gallbladder via the cystic duct. Bile passes into the duodenum through the ampulla of Vater regulated by the sphincter of Oddi.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 39
Correct
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Regarding T helper cells, which of the following statements is CORRECT:
Your Answer: They form the vast majority (about 75%) of the total circulating T-cell population.
Explanation:CD4+ T-cells (Helper T cells)Recognise antigen only in association with HLA class II molecules (found on antigen presenting cells (APCs) e.g. dendritic cells, B-cells; present exogenous antigens that have been phagocytosed/endocytosed into intracellular vesicles)Form most of the circulating T-cell population (about 75%)Secrete cytokines (e.g. IFN-gamma) which are required for recruitment and activation of other immune cells such as macrophages, T cytotoxic cells and NK cells and for the activation of and production of immunoglobulin from B-cells
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 40
Incorrect
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A patient presents with an acute severe asthma attack. Following a poor response to his initial salbutamol nebuliser, you administer a further nebuliser that this time also contains ipratropium bromide.
After what time period would you expect the maximum effect of the ipratropium bromide to occur? Select ONE answer only.Your Answer: 10-15 minutes
Correct Answer: 30 -60 minutes
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.
The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.
The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.
The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma) -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 41
Incorrect
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An elderly female has a bacterial infection and you are asked to prescribe an antibiotic to her. This antibiotic is a nucleic acid synthesis inhibitor.
Which of the following antimicrobial drugs will be prescribed to this patient?Your Answer: Chloramphenicol
Correct Answer: Metronidazole
Explanation:Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.
Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors.
Erythromycin inhibits protein synthesis and blocks translocation by binding to the 23S rRNA of the 50S ribosomal subunit.
Chloramphenicol blocks peptidyl transferase at 50S ribosomal subunit.
Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.
An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
1. Inhibition of cell wall synthesis
– Penicillins
– Cephalosporins
– Vancomycin
2. Disruption of cell membrane function
– Polymyxins
– Nystatin
– Amphotericin B
3. Inhibition of protein synthesis
– Macrolides
– Aminoglycosides
– Tetracyclines
– Chloramphenicol
4. Inhibition of nucleic acid synthesis
– Quinolones
– Trimethoprim
– 5-nitroimidazoles
– Rifampicin
5. Anti-metabolic activity
– Sulphonamides
– Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 42
Correct
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A 30-year-old man suffers from an open femoral shaft fracture after being involved in a road traffic accident. As a consequence of his injury, the nerve that was damaged innervates the popliteus muscle.
In which of the following nerves is the popliteus muscle innervated by?Your Answer: Tibial nerve
Explanation:The popliteus muscle is innervated by the tibial nerve (L4, 5 and S1).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 43
Correct
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What is nimodipine used predominantly in the treatment of?
Your 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 44
Incorrect
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Which of the following statements regarding hookworm is FALSE:
Your Answer: Treatment is with mebendazole or albendazole.
Correct Answer: Transmission of hookworm is via ingestion of contaminated food and water.
Explanation:The hookworm life cycle begins with the passage of eggs from an adult host into the stool. Hookworm eggs hatch in the soil to release larvae that mature into infective larvae. Infection is usually transmitted by larval penetration into human skin (duodenal infection may also be transmitted by the oral route). From the skin, larvae migrate into the blood vessels and are carried to the lungs, where they penetrate the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 45
Incorrect
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A 20-year-old male patient lives in a travelling community and has never received any vaccinations. He presents to you with fever.
Which of these statements concerning indications and contraindications for vaccination is TRUE?
Your Answer: The BCG vaccination can be safely administered to patients with HIV
Correct Answer: Inactivated vaccines are safe in pregnancy
Explanation:All vaccines are contraindicated in individuals with: A confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.
A confirmed anaphylactic reaction to a component in the vaccine e.g. neomycinThere is no evidence that vaccinating pregnant women with inactivated vaccine or toxoids harms the woman or foetus.
The current protocol is that a child with history of egg allergy can be safely vaccinated with Fluenz tetra. However, if they had a previous severe anaphylaxis to egg requiring intensive care, then Flenz tetra is contraindicated.
BCG, yellow fever or oral typhoid vaccinations are not safe in HIV positive patients.
The normal times recommended for immunization of full-term babies should also be applied to premature infants and correction for gestational age should not be implemented.
Concurrent antibiotic therapy is not a contraindication to vaccination.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 46
Correct
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The following statements concerning lung compliance is true EXCEPT?
Your Answer: Lung compliance is described by the equation: C = ∆ P/ ∆V, where C = compliance, P = pressure, and V = volume
Explanation:Lung compliance is the change in volume per unit change in distending pressure.
It is calculated using the equation:
Lung compliance = ΔV / ΔP
Where:
ΔV is the change in volume
ΔP is the change in pleural pressure.Lung compliance is inversely proportional to stiffness and elastance.
It comprises static (no airflow) and dynamic (during continuous breathing) components.
It is the slope of the pressure-volume curve.
Lung compliance describes the distensibility of the lungs and the chest wall.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 47
Incorrect
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Fracture of the medial epicondyle would result to the following, except
Your Answer: Weakness of adduction of the fingers
Correct Answer: Weakness of abduction of the thumb
Explanation:Thumb abduction is mediated by the abductor pollicis longus and brevis, which are innervated by the radial and median nerves, respectively.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 48
Correct
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What is the main mechanism of action of dobutamine as an inotropic sympathomimetic:
Your Answer: Beta1-receptor agonist
Explanation:Dobutamine directly stimulates the beta1-adrenergic receptors in the heart and increases contractility and cardiac output with little effect on the rate. In addition action on beta2-receptors causes vasodilation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 49
Correct
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Regarding fat digestion, which of the following statements is CORRECT:
Your 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 50
Incorrect
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Which of the following is NOT a function of antibodies:
Your Answer: Opsonise antigens for phagocytosis
Correct Answer: Act as antigen receptors on T lymphocytes
Explanation:Antibodies:
Neutralise toxins and prevent attachment of pathogens
Target, opsonise or agglutinate (clump together) antigens for phagocytosis
Activate the complement cascade (leading to lysis or opsonisation of the pathogen)
Act as antigen receptors on B lymphocytes
Activate antibody-dependent cell-mediated cytotoxicity by natural killer (NK) cells or T cytotoxic cells
Provide mucosal immunity (IgA-mediated)
Stimulate degranulation of mast cells (IgE and IgG mediated)
Provide passive immunity to the newborn (through transplacental passage of IgG and secretion of IgA in breast milk) -
This question is part of the following fields:
- Immune Responses
- Pathology
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