-
Question 1
Correct
-
Regarding conduction of nerve impulses, which of the following statements is CORRECT:
Your Answer: The action potential in myelinated axons is propagated only at the nodes of Ranvier.
Explanation:An action potential is a self-propagating response, successive depolarisation moving along each segment of an unmyelinated nerve until it reaches the end. It is all-or-nothing and does not decrease in size. Conduction in myelinated fibres is much faster, up to 50 times that of the fastest unmyelinated nerve. Myelinated fibres are insulated except at areas devoid of myelin called nodes of Ranvier. The depolarisation jumps from one node of Ranvier to another by a process called saltatory conduction. Saltatory conduction not only increases the velocity of impulse transmission but also conserves energy for the axon because depolarisation only occurs at the nodes and not along the whole length of the nerve fibre. Larger diameter myelinated nerve fibres conduct nerve impulses faster than small unmyelinated nerve fibres.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 2
Correct
-
A patient with a high potassium level is at risk of going into cardiac arrest. What changes in the ECG may indicate the incident of cardiac arrest in this patient?
Your Answer: Peaked T waves and broad QRS complex
Explanation:Severe hyperkalaemia can result in a heart attack or a life-threatening arrhythmia. T waves become narrow-based, pointed, and tall if hyperkalaemia is not treated. The QRS complex widens and eventually merges with the T wave, resulting in a classic sine-wave electrocardiogram. Ventricular fibrillation and asystole are likely to follow.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 3
Incorrect
-
A 63-year-old man complains of chest pain and syncope on occasion. His heart rate is 37 beats per minute, and he has a second-degree heart block, according to his rhythm strip.Which of the following would be the most appropriate next step in his management, according to the ALS bradycardia algorithm?
Your Answer: Set up transcutaneous pacing
Correct Answer: Give atropine 500 mcg
Explanation:Atropine is used to treat bradycardia (sinus, atrial, or nodal) or AV block when the patient’s haemodynamic condition is compromised by the bradycardia.If any of the following adverse features are present, the ALS bradycardia algorithm recommends a dose of atropine 500 mcg IV:ShockSyncopeMyocardial ischemiaInsufficiency of the heartIf this does not work, give additional 500 mcg doses at 3-5 minute intervals until a maximum dose of 3 mg is reached. The heart rate can be slowed paradoxically if the dose is higher than 3 mg.The ALS bradycardia algorithm also suggests the following interim measures:Transcutaneous pacingIsoprenaline infusion 5 mcg/minAdrenaline infusion 2-10 mcg/minutesAlternative drugs (aminophylline, dopamine, glucagon, glycopyrrolate)
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 4
Correct
-
A 32-year-old woman with a history of bipolar disorder exhibits lithium toxicity symptoms.Which of the following is the MOST LIKELY feature to be present?
Your Answer: Clonus
Explanation:Lithium toxicity manifests itself in the following ways:AtaxiaClonusComaConfusionConvulsionsDiarrhoeaIncreased muscle toneNausea and vomitingNephrogenic diabetes insipidusRenal failureTremor
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 5
Correct
-
A dermatological examination on a patient presenting with a lump shows a small visible skin elevation containing an accumulation of pus.Which one of these best describes the lump you have found on examination?
Your Answer: Pustule
Explanation:A pustule is a small visible skin elevation containing an accumulation of pus. A carbuncle is a collection of individual boils clustered together. A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter. A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus. A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 6
Incorrect
-
A 22 year old male has been stabbed and is brought to the ED with a stab wound to his upper limb. On examination, the patient is unable to flex the distal interphalangeal joints of the ring and little finger. However, the proximal interphalangeal joint is intact. The most likely affected nerve is which of the following, and at which level is this occurring?
Your Answer: Median nerve at elbow
Correct Answer: Ulnar nerve at elbow
Explanation:The medial half of the flexor digitorum profundus is innervated by the ulnar nerve. Paralysis of this muscle results in loss of flexion at the distal interphalangeal joint of the ring and little finger. Flexion at the proximal interphalangeal joint is preserved as this is a function of the flexor digitorum superficialis which is innervated by the median nerve. The ulnar nerve is not correct as ulnar nerve injury at the wrist would not affect the long flexors, and the injury must have been more proximal.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 7
Incorrect
-
A 29-year-old woman with a skin infection not responding to first-line antibiotics return for a review clinic appointment. The result of her culture shows growth of methicillin-resistant Staphylococcus aureus (MRSA).Which among the following antibiotics is methicillin-resistant Staphylococcus aureus usually sensitive to?
Your Answer: Ceftriaxone
Correct Answer: Linezolid
Explanation:Historically, MRSA has been treated successfully with outpatient oral sulphonamides, clindamycin, rifampin, doxycycline, or a combination of these agents. With the development of increasing drug resistance of MRSA to these traditional antimicrobials, there has been a search for more effective antibiotics. One recent study demonstrated that vancomycin, linezolid, and quinupristin-dalfopristin were the most effective antibiotics against multiple strains of MRSA.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 8
Correct
-
A 70-year-old man has a resting tremor, rigidity, bradykinesia, and a shuffling gait. Parkinson's disease is caused by one of the following mechanisms:
Your Answer: Loss of dopaminergic neurons in the substantia nigra
Explanation:Parkinson’s disease (PD) is one of the most common neurologic disorders, affecting approximately 1% of individuals older than 60 years and causing progressive disability that can be slowed but not halted, by treatment. The 2 major neuropathologic findings in Parkinson’s disease are loss of pigmented dopaminergic neurons of the substantia nigra pars compacta and the presence of Lewy bodies and Lewy neurites. See the images below.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 9
Correct
-
A 27-year-old man was sent to the emergency department by ambulance with suspected anaphylaxis. What is the best first-line treatment for this patient?
Your Answer: 500 micrograms of adrenaline intramuscularly
Explanation:Anaphylaxis is the sudden onset of systemic hypersensitivity due to IgE-mediated chemical release from mast cells and basophils. If anaphylaxis is suspected, 500 micrograms of adrenaline should be administered promptly (0.5 ml of 1:1000 solution). In anaphylaxis, the intramuscular route is the most immediate approach; the optimal site is the anterolateral aspect of the middle part of the thigh. Intravenous adrenaline should only be given by people who are well-versed in the use and titration of vasopressors in their routine clinical practice.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 10
Incorrect
-
A 27-year-old female is brought to the Emergency Department by ambulance with extensive bleeding from her upper arm following a fall from a bicycle onto a fence. On inspection her biceps brachii muscle has been lacerated.How will the muscle heal from this injury? Select ONE answer only.
Your Answer: Scar formation with no myocyte regeneration
Correct Answer: Satellite cells will produce a small number of regenerated myocytes
Explanation:Muscle heals with fibrous tissue to form a scar. Once cut, it will never regain its previous bulk or power. Within the scar a small number of myocytes (muscle cells) may be seen, which are formed from satellite cells but they contribute little to the function of the muscle overall.In more widespread ischaemic injury, such as critical ischaemic limb due to arterial compromise, or in compartment syndrome, damaged myocytes are replaced diffusely with fibrous tissue. This fibrous tissue contracts and reduces movement, and in extreme cases can pull the limb into abnormal positions such as in Volkmann’s ischaemic contracture of the forearm.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 11
Incorrect
-
Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer: Diabetes insipidus causes hypernatraemia secondary to a pure water deficit.
Correct Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 12
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: Non-Hodgkin’s lymphoma
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 groupStage II two involved lymph node groups on one side of the diaphragmStage III: lymph node groups involved on both sides of the diaphragmStage IV: Involvement of extra-nodal tissues, such as the liver or bone marrowDiagnosis 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.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 13
Incorrect
-
Cardiac muscle and skeletal muscle are alike, but there are a few key variations. Which of the following is NOT a characteristic of skeletal muscle but is a characteristic of cardiac muscle?Â
Your Answer: Contraction by excitation-contraction coupling
Correct Answer: The presence of intercalated discs
Explanation:Cardiac muscle is striated, and the sarcomere is the contractile unit, similar to skeletal muscle. Contracture is mediated by the interaction of calcium, troponins, and myofilaments, much as it occurs in skeletal muscle. Cardiac muscle, on the other hand, differs from skeletal muscle in a number of ways.In contrast to skeletal muscle cells, cardiac myocytes have a nucleus in the middle of the cell and sometimes two nuclei. The cells are striated because the thick and thin filaments are arranged in an orderly fashion, although the arrangement is less well-organized than in skeletal muscle.Intercalated discs, which work similarly to the Z band in skeletal muscle in defining where one cardiac muscle cell joins the next, are a very significant component of cardiac muscle.Adherens junctions and desmosomes, which are specialized structures that hold the cardiac myocytes together, are formed by the transverse sections. The lateral sections produce gap junctions, which join the cytoplasm of two cells directly, allowing for rapid action potential conduction. These critical properties allow the heart to contract in a coordinated manner, allowing for more efficient blood pumping.Cardiac myocytes have the ability to create their own action potentials, which is referred to as myogenic’. They can depolarize spontaneously to initiate a cardiac action potential. Pacemaker cells, as well as the sino-atrial (SA) and atrioventricular (AV) nodes, control this.The Purkinje cells and the cells of the bundle of His are likewise capable of spontaneous depolarization. While the bundle of His is made up of specialized myocytes, it’s vital to remember that Purkinje cells are not myocytes and have distinct characteristics. They are larger than myocytes, with fewer filaments and more gap junctions than myocytes. They conduct action potentials more quickly, allowing the ventricles to contract synchronously.Cardiac myocytes contract by excitation-contraction coupling, just like skeletal myocytes. Heart myocytes, on the other hand, utilise a calcium-induced calcium release mechanism that is unique to cardiac muscle (CICR). The influx of calcium ions (Ca2+) into the cell causes a ‘calcium spark,’ which causes more ions to be released into the cytoplasm.An influx of sodium ions induces an initial depolarisation, much as it does in skeletal muscle; however, in cardiac muscle, the inflow of Ca2+ sustains the depolarisation, allowing it to remain longer. Due to potassium ion (K+) inflow, CICR causes a plateau phase in which the cells remain depolarized for a short time before repolarizing. Skeletal muscle, on the other hand, repolarizes almost instantly.Comparison of skeletal and cardiac muscle:Skeletal muscle Cardiac muscleStriation Striated but arrangement less organised Multiple nuclei located peripherally Usually single nucleus (but can be two), located centrallyDiscs None Intercalated discsNo Gap junctions Gap junctions No Pacemaker PacemakerElectrical stimulation: Nervous system (excitation) Pacemaker (excitation)
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 14
Correct
-
A 66-year-old female with a history of stroke one year ago presents to the Family Medicine clinic complaining of fatigue, weight loss, and tongue discolouration. On examination, she seems malnourished, her tongue is beefy red, and an ataxic gait pattern is noticed. Which ONE of the following conditions does this patient most likely have?
Your Answer: Vitamin B12 deficiency
Explanation:A history of stroke and poor nutritional status points towards a nutritional deficiency as the most likely cause of her symptoms. The examination would differentiate between Vitamin B12 and Folic acid deficiency as in the former. The patient has a beefy red tongue and symptoms indicating peripheral nervous system involvement or subacute combined spinal cord degeneration. The patient may also have a lemon-yellow skin colour, loss of proprioception and vibratory sense and oral ulceration. Investigations in B12 deficiency can reveal the following:1. Macrocytic anaemia2. Neutropoenia3. Thrombocytopaenia4. Blood film: anisocytosis, poikilocytosis5. Low serum B126. Raised serum bilirubin (haemolysis)7. Intrinsic factor antibodies8. Positive Schilling test
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 15
Incorrect
-
A new blood test is being developed to diagnose DVT. 1000 people presenting to ED with suspected DVT undergo the new blood test and the gold standard doppler ultrasound to confirm the diagnosis. Of the 1000 people, 77 are confirmed to have a DVT. Of the patients diagnosed with DVT, 75 test positive with the new diagnostic test and of the patients not diagnosed with DVT, 125 test positive with the new diagnostic test. What is the negative predictive value of this test:DVT YesDVT NoTotalPositive testa= 75b = 125200Negative testc = 2d = 798800Total779231000
Your Answer: 0.86
Correct Answer: 0.99
Explanation:Negative predictive value (NPV) is the proportion of individuals with a negative test result who do not have the disease.Negative predictive value (NPV) = d/(c+d) = 798/800 = 0.99 = 99%This means there is a 99% chance, if the test is negative, that the patient does not have a DVT.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 16
Incorrect
-
The monospot test for infectious mononucleosis uses which of the following types of red blood cell?
Your Answer: Ox red blood cells
Correct Answer: Horse red blood cells
Explanation:Infectious mononucleosis can be diagnosed using specific EBV antibodies and a variety if unrelated non-EBV heterophile antibodies. These antibodies can be detected by two main screening tests:The monospot test uses horse red blood cells. It agglutinates in the presence of heterophile antibodies.Sheep red blood cells is used in Paul-Bunnell test. The blood agglutinates in the presence of heterophile antibodies.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 17
Correct
-
Herpes simplex encephalitis has a predilection for which of the following sites:
Your Answer: Temporal lobe
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.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 18
Correct
-
Which of the following anatomical structures is most likely the cause of oedema and erythema of the arm in a patient who underwent modified radical mastectomy and radiotherapy?
Your Answer: Axillary lymph nodes
Explanation:Arm oedema is one of the sequelae after breast cancer surgery and radiation therapy. Arm oedema in the breast cancer patient is caused by interruption of the axillary lymphatic system by surgery or radiation therapy, which results in the accumulation of fluid in subcutaneous tissue in the arm, with decreased distensibility of tissue around the joints and increased weight of the extremity. Chronic inflammatory changes result in both subcutaneous and lymph vessel fibrosis.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 19
Correct
-
Gastric emptying is increased by all of the following EXCEPT for:
Your Answer: Secretin
Explanation:Gastric emptying is increased by:Distension of the pyloric antrumA fall in the pH of chyme in the stomachParasympathetic stimulation (via vagus)GastrinThe hormones secretin, cholecystokinin and gastric inhibitory polypeptide (GIP) inhibit gastric emptying.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 20
Correct
-
Which of the following is the most common cause of hyperthyroidism:
Your Answer: Graves disease
Explanation:Graves disease is the most common cause of hyperthyroidism. It is an autoimmune disease in which autoantibodies against TSH receptors are produced. These antibodies bind to and stimulate these TSH receptors leading to an excess production of thyroid hormones. Therefore, the signs and symptoms of Graves disease are the same as those of hyperthyroidism, reflecting the actions of increased circulating levels of thyroid hormones: increased heat production, weight loss, increased 02 consumption and cardiac output and exophthalmos (bulging eyes, not drooping eyelids). TSH levels will be decreased (not increased) as a result of the negative feedback effect of increased T3 levels on the anterior pituitary.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 21
Correct
-
Question 22
Correct
-
Carbamazepine is contraindicated in which of the following:
Your Answer: Atrioventricular block
Explanation:Carbamazepine is contraindicated in:- People with known hypersensitivity to carbamazepine or structurally related drugs- People with atrioventricular block (may suppress AV conduction and ventricular automaticity)- People with a history of bone marrow depression (risk of agranulocytosis and aplastic anaemia)- People with a history of acute porphyrias- People taking a monoamine oxidase inhibitor (risk of serotonin syndrome)
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 23
Incorrect
-
Regarding acute myeloid leukaemia (AML), which of the following statements is CORRECT:
Your Answer: AML is characterised by plasma cell accumulation on the bone marrow.
Correct Answer: AML becomes increasingly common with age.
Explanation:Acute myeloid leukaemia (AML) is the most common form of acute leukaemia in adults and becomes increasingly common with age, with a median onset of 65 years. It forms only a minor fraction (10 – 15%) of childhood leukaemia. The clinical features of AML typically presents with clinical features secondary to leukaemic infiltration of bone marrow and extramedullary sites: Anaemia (lethargy, pallor and breathlessness)Thrombocytopaenia (petechiae, bruising, epistaxis, haemorrhage) – often profoundNeutropenia (infections)HepatosplenomegalyGingival infiltrationCentral nervous system involvement in AML is uncommon.Leukaemia cutis is the infiltration of neoplastic leukocytes in the skin. It occurs in approximately 10% of patients with AML.Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. The total white cell count is usually increased and blood film examination typically shows a variable number of blast cells. The bone marrow is hypercellular and typically contains many blast cells.. The prognosis for patients with AML has been improving steadily, particularly for those under 60 years of age, and approximately one-third of patients of this group can expect to achieve long-term cure. For the elderly, the situation is poor and less than 10% of those over 70 years of age achieve long-term remission.CML is commonly associated with the Philadelphia chromosome. The Philadelphia chromosome is present in only 1% of adults AML cases.Lymphadenopathy is rare in AML.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 24
Correct
-
The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 25
Incorrect
-
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: Disruption of cell membrane function
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.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 26
Incorrect
-
An 82 year old man has fever, left sided abdominal and back pain and presents to the emergency room. Imaging reveals a large perinephric abscess. Which of the following most likely describes the fluid location:
Your Answer: Between the renal capsule and the perinephric fat
Correct Answer: Between the renal capsule and the renal fascia
Explanation:The perinephric fat is immediately external to the renal capsule and completely surrounds the kidney. The renal fascia surrounds the perinephric fat and the paranephric fat is external to the renal fascia. The location of a perinephric abscess is in the perinephric fat between the renal capsule and the renal fascia.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 27
Incorrect
-
Regarding the hard palate, which of the following statements is CORRECT:
Your Answer: The posterior one-quarter of the hard palate is formed by the maxillae.
Correct Answer: Lymphatic vessels from the palate usually drain into deep cervical lymph nodes.
Explanation:Lymphatic vessels from the pharynx and palate drain into the deep cervical lymph nodes.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 28
Correct
-
Which statement accurately describes the osmolality in the various parts of the Henle Loop?
Your Answer: The osmolality of fluid in the descending loop equals that of the peritubular fluid
Explanation:The Loop of Henle connects the proximal tubule to the distal convoluted tubule and lies parallel to the collecting ducts. It consists of three major segments, including the descending thin limb, the ascending thin limb, and the ascending thick limb. These segments are differentiated based on structure, anatomic location, and function. The main function of the loop of Henle is to recover water and sodium chloride from urine. When fluid enters the loop of Henle, it has an osmolality of approximately 300 mOsm, and the main solute is sodium. The thin descending limb has a high water permeability but a low ion permeability. Because it lacks solute transporters, it cannot reabsorb sodium. Aquaporin 1 (AQP1) channels are used to passively absorb water in this area. The peritubular fluid becomes increasingly concentrated as the loop descends into the medulla, causing water to osmose out of the tubule. The tubular fluid in this area now equalizes to the osmolality of the peritubular fluid, to a maximum of approximately 1200 mOsm in a long medullary loop of Henle and 600 mOsm in a short cortical loop of Henle. The thin ascending limb is highly permeable to ions and impermeable to water. It allows the passive movement of sodium, chloride, and urea down their concentration gradients, so urea enters the tubule and sodium and chloride leave. Reabsorption occurs paracellularly due to the difference in osmolarity between the tubule and the interstitium. The thick ascending limb is also impermeable to water but actively transports sodium, potassium, and chloride out of the tubular fluid. The osmolality of the tubular fluid is lower compared to the surrounding peritubular fluid. This area is water impermeable. This results in tubular fluid leaving the loop of Henle with an osmolality of approximately 100 mOsm, which is lower than the osmolality of the fluid entering the loop, and urea being the solute.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 29
Correct
-
A dermatological examination of a patient presenting with a lump shows a visible collection of fluid measuring 0.3 cm in diameter.Which one of these best describes the lump you have found on examination?
Your Answer: Vesicle
Explanation:A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus. A carbuncle is a collection of individual boils clustered together. A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter. A pustule is a small visible skin elevation containing an accumulation of pus.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 30
Correct
-
Which of the following statements is correct regarding anti-D immunoglobulin?
Your Answer: It is administered as part of routine antenatal care for rhesus-negative mothers.
Explanation:In all non-sensitised pregnant women who are RhD-negative, it is recommended that routine antenatal anti-D prophylaxis is offered. Even if there is previous anti-D prophylaxis, use of routine antenatal anti-D prophylaxis should be given for a sensitising event early in the same pregnancy. Postpartum anti-D prophylaxis should also be given even if there has been previous routine antenatal anti-D prophylaxis or antenatal anti-D prophylaxis for a sensitising event in the same pregnancy.
-
This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
-
-
Question 31
Correct
-
A 50-year-old man from Russia presents with a history of cough with blood-stained sputum, fever, night sweats, and weight loss. Suspecting tuberculosis, you begin investigations.All the following statements regarding tuberculosis (TB) are true EXCEPT?
Your Answer: Corticosteroid use is not a risk factor for developing TB
Explanation:Immunosuppressants like corticosteroids may be an important risk factor for developing tuberculosis. All of the other statements are true.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 32
Correct
-
Which of the following muscles acts as an extensor of the shoulder joint?
Your Answer: Teres major
Explanation:The glenohumeral joint possesses the capability of allowing an extreme range of motion in multiple planes.Flexion – Defined as bringing the upper limb anterior in the sagittal plane. The usual range of motion is 180 degrees. The main flexors of the shoulder are the anterior deltoid, coracobrachialis, and pectoralis major. Biceps brachii also weakly assists in this action.Extension—Defined as bringing the upper limb posterior in a sagittal plane. The normal range of motion is 45 to 60 degrees. The main extensors of the shoulder are the posterior deltoid, latissimus dorsi, and teres major.Internal rotation—Defined as rotation toward the midline along a vertical axis. The normal range of motion is 70 to 90 degrees. The internal rotation muscles are the subscapularis, pectoralis major, latissimus dorsi, teres major, and the anterior aspect of the deltoid.External rotation – Defined as rotation away from the midline along a vertical axis. The normal range of motion is 90 degrees. Primarily infraspinatus and teres minor are responsible for the motion.Adduction – Defined as bringing the upper limb towards the midline in the coronal plane. Pectoralis major, latissimus dorsi, and teres major are the muscles primarily responsible for shoulder adduction.Abduction – Defined as bringing the upper limb away from the midline in the coronal plane. The normal range of motion is 150 degrees. Due to the ability to differentiate several pathologies by the range of motion of the glenohumeral joint in this plane of motion, it is essential to understand how different muscles contribute to this action.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 33
Correct
-
Which of the following muscles are primarily involved in passive inspiration:
Your Answer: Diaphragm and external intercostal muscles
Explanation:Passive inspiration is produced by contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs). In inspiration, elevation of the sternal ends of the ribs (‘pump handle’ movement), elevation of the lateral shafts of the ribs (‘bucket handle’ movement) and depression of the diaphragm result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in an increased intrathoracic volume and decreased intrathoracic pressure and thus air is drawn into the lungs.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 34
Correct
-
Regarding co-amoxiclav, which of the following statements is INCORRECT:
Your Answer: Clavulanic acid acts to inhibit cross-linking of bacterial peptidoglycan polymers.
Explanation:Co-amoxiclav consists of amoxicillin with the beta-lactamase inhibitor clavulanic acid. Clavulanic acid itself has no significant antibacterial activity but, by inactivating beta-lactamases, it makes the combination active against beta-lactamase-producing bacteria that are resistant to amoxicillin.The most common adverse effects of co-amoxiclav include nausea, vomiting, skin rash and diarrhoea. Pseudomembranous colitis should be considered if a person develops severe diarrhoea during or after treatment with co-amoxiclav. Cholestatic jaundice can occur either during or shortly after the use of co-amoxiclav. An epidemiological study has shown that the risk of acute liver toxicity was about 6 times greater with co-amoxiclav than with amoxicillin. Cholestatic jaundice is more common in patients above the age of 65 years and in men; these reactions have only rarely been reported in children. Jaundice is usually self-limiting and very rarely fatal.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 35
Correct
-
A young patient presents with the features of an easily recognisable infectious disease.Which of the following infectious diseases typically has an incubation period of less than 1 week? Select ONE answer only.
Your Answer: Cholera
Explanation:Cholera has an incubation period of 12 hours to 6 days.Other infectious disease that have an incubation period of less than 1 week include:Staphylococcal enteritis (1-6 hours)Salmonella enteritis (12-24 hours)Botulism (18-36 hours)Gas gangrene (6 hours to 4 days)Scarlet fever (1-4 days)Diphtheria (2-5 days)Gonorrhoea (3-5 days)Yellow fever (3-6 days)Meningococcaemia (1-7 days)Brucellosis has an incubation period of 7-21 days.Measles has an incubation period of 14-18 days.Falciparum malaria usually has an incubation period of 7-14 days. The other forms of malaria have a longer incubation period of 12-40 days.Rubella has an incubation period of 14-21 days.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 36
Correct
-
Which of the following would you NOT expect from a deep fibular nerve palsy:
Your Answer: Loss of sensation over heel
Explanation:Damage to the deep fibular nerve results in loss of dorsiflexion of the ankle, with resultant foot drop with high-stepping gait, loss of toe extension, weakness of foot inversion and loss of sensation over the webspace between the 1st and 2nd toes.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 37
Correct
-
Regarding the UK routine childhood immunisation schedule which of the following vaccines is NOT given at 4 months:
Your Answer: Rotavirus
Explanation:At 4 months the following vaccines are given:Diphtheria, tetanus, pertussis, polio, Hib and hepatitis B (3rd dose)Meningococcal group B (2nd dose)
-
This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
-
-
Question 38
Incorrect
-
Which of the following statements is incorrect regarding the electron transfer system?
Your Answer: The electron transfer system is located on the cristae of the mitochondrion.
Correct Answer: The electron transfer system occurs in anaerobic respiration.
Explanation:The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 39
Correct
-
Which of the following best describes the mechanism of action of aspirin:
Your Answer: Cyclo-oxygenase (COX) inhibitor
Explanation:Aspirin is a non-steroidal anti-inflammatory drug (NSAID). Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes and the resulting inhibition of prostaglandin synthesis results in analgesic, antipyretic and to a lesser extent anti-inflammatory actions.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 40
Incorrect
-
The following all cause a left shift in the oxygen dissociation curve EXCEPT for:
Your Answer: Decrease in 2,3-DPG
Correct Answer: Decrease in pH
Explanation:An increased affinity of haemoglobin for oxygen, shown by a left shift in the oxygen dissociation curve, is caused in the lungs by a rise in pH, a fall in PCO2,a decrease in temperature and a decrease in 2,3 -DPG. Carbon monoxide (CO) binds 240 times more strongly than O2to haemoglobin and by occupying O2-binding sites, reduces oxygen capacity. CO also increases oxygen affinity, shifting the oxygen haemoglobin curve to the left and making O2release to tissues more difficult.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 41
Correct
-
A 50-year-old man, known hypertensive on amlodipine has been visiting his GP with symptoms of headache, tiredness, and muscle weakness. His blood test today shows a low potassium level of 2.8 mmol/L, and a slightly raised sodium level at 147 mmol/L.What is the MOST LIKELY diagnosis?
Your Answer: Conn’s syndrome
Explanation:When there are excessive levels of aldosterone independent of the renin-angiotensin aldosterone axis, primary hyperaldosteronism occurs. Secondary hyperaldosteronism occurs due to high renin levels.Causes of primary hyperaldosteronism include:Conn’s syndromeAdrenal hyperplasiaAdrenal cancerFamilial aldosteronismCauses of secondary hyperaldosteronism include:Renal vasoconstrictionOedematous disordersDrugs – diureticsObstructive renal artery diseaseAlthough patients are usually asymptomatic, when clinical features are present, classically hyperaldosteronism presents with:HypokalaemiaSodium levels can be normal or slightly raisedHypertensionMetabolic alkalosisLess common, clinical features are:LethargyHeadachesIntermittent paraesthesiaPolyuria and polydipsiaMuscle weakness (from persistent hypokalaemia)Tetany and paralysis (rare)
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 42
Correct
-
A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.Glucagon is produced in which of the following cells? Select ONE answer only.
Your Answer: Alpha-cells in the pancreas
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline. Glucagon then causes:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 43
Correct
-
A 59-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.Which of the following is abciximab (ReoPro) mechanism of action?
Your Answer: Antagonism of the glycoprotein IIb/IIIa receptor
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 44
Incorrect
-
A lesion to which part of the optic radiation will result in contralateral homonymous inferior quadrantanopia?
Your Answer: Left parietal lobe
Correct Answer: Right parietal lobe
Explanation:A visual loss in the lower left quadrant in both visual fields is an indication of an inferior homonymous. This is due to a lesion of the superior fibres of the optic radiation in the parietal lobe on the contralateral side of the visual pathway.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 45
Correct
-
A 34-year-old male presents to the Emergency Department with the complaint of palpitations and difficulty breathing, which started suddenly half an hour ago. His ECG shows findings of supraventricular tachycardia. You attempt vagal manoeuvres but cannot convert them back to sinus rhythm. Therefore, drug therapy is necessary to terminate the arrhythmia. Adenosine cannot be used in this patient because of a contra-indication listed in his medical record. Which one of the conditions listed below would be a contraindication in this case?
Your Answer: Asthma
Explanation:Entonox is a mixture of 50% Oxygen and 50% nitrous oxide and is given in an inhaled form as a quick form of analgesia. Entonox causes non-competitive inhibition of NMDA (N-methyl-D-aspartate) receptors, which are a subtype of the glutamate receptor. It is stored in blue and white cylinders and administered via a pressure regulator and demand valve. The administration of this medicine reduces pain and anxiety in paediatric and dental procedures ands during labour. Effects are apparent after 20 seconds, and peak action occurs after 3 to 5 minutes as it is a drug with a rapid onset and the patient will also recover rapidly from its effects. Entonox is widely used as it does not accumulate in the body and does not cause many side effects. However, a notable side effect is the inhibition of Vitamin B12 synthesis.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 46
Correct
-
A patient suffers an injury to the nerve that innervates gluteus medius.​The gluteus medius muscle is innervated by which of the following nerves? Select ONE answer only.
Your Answer: Superior gluteal nerve
Explanation:Gluteus minimus is innervated by the superior gluteal nerve.Gluteus medius is innervated by the superior gluteal nerve.Gluteus maximus is innervated by the inferior gluteal nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 47
Incorrect
-
Which of the following does NOT predispose to digoxin toxicity in a patient taking digoxin:
Your Answer: Hypokalaemia
Correct Answer: Hyponatraemia
Explanation:Hypoxia, hypercalcaemia, hypokalaemia and hypomagnesaemia predispose to digoxin toxicity. Care should also be taken in the elderly who are particularly susceptible to digoxin toxicity. Hypokalaemia may be precipitated by use of diuretics. Although hyponatremia can result in the development of other pathological disturbances, it does not potentiate digoxin toxicity.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 48
Correct
-
Which of the following classes of drugs may predispose to lithium toxicity:
Your Answer: Thiazide diuretics
Explanation:Excretion of lithium may be reduced by thiazide diuretics, NSAIDs, and ACE inhibitors thus predisposing to lithium toxicity. Loop diuretics also cause lithium retention but are less likely to result in lithium toxicity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 49
Incorrect
-
Regarding the heart sounds in the cardiac cycle, which of the following statements is INCORRECT:
Your Answer: The fourth heart sound is heard in late diastole.
Correct Answer: The third heart sound is caused by filling of an abnormally stiff ventricle in atrial systole.
Explanation:Heart Sound – Phase of Cardiac Cycle – Mechanical Event:First heart sound – Start of systole – Caused by closure of the atrioventricular (mitral & tricuspid) valvesSecond heart sound – End of systole – Caused by closure of the semilunar (aortic and pulmonary) valvesThird heart sound – Early diastole – Caused by rapid flow of blood from the atria into the ventricles during the ventricular filling phaseFourth heart sound – Late diastole – Caused by filling of an abnormally stiff ventricle in atrial systole
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 50
Correct
-
Regarding cellular respiration, which of the following statements is CORRECT:
Your Answer: When fats are used as the primary energy source, an excess of acetyl-CoA is produced.
Explanation:Cellular respiration is the process by which cells obtain energy in the form of adenosine triphosphate (ATP). ATP transfers chemical energy from the energy rich substances in the cell to the cell’s energy requiring reactions e.g. active transport, DNA replication and muscle contraction.Cellular respiration is essentially a three step process: 1) Glycolysis, 2)The Krebs cycle, 3)The electron transfer system.The main respiratory substrate used by cells is 6-carbon glucose. Fats and proteins can also be used as respiratory substrates. When fats are being used as the primary energy source, in the absence of glucose, an excess amount of acetyl-CoA is produced, and is converted into acetone and ketone bodies. This can occur in starvation, fasting or in diabetic ketoacidosis. Proteins are used as an energy source only if protein intake is very high, or if glucose and fat sources are depleted.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 51
Incorrect
-
Which of the following is NOT a common side effect of antihistamines:
Your Answer: Gastrointestinal disturbance
Correct Answer: Tremor
Explanation:Common side effects of antihistamines may include:Anticholinergic effects (blurred vision, dry mouth, urinary retention)HeadacheGastrointestinal disturbancesPsychomotor impairment (sedation, dizziness and loss of appetite)These side effects are significantly reduced with second-generation agents.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 52
Incorrect
-
Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: Flow through airways is inversely proportional to airway resistance.
Correct Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 53
Correct
-
1-alpha-hydroxylase is a cytochrome p450 enzyme that is involved in the production of vitamin D's hormonally active metabolite.Which of the following promotes the activity of 1-alpha-hydroxylase?
Your Answer: Parathyroid hormone
Explanation:1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney.The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is promoted by parathyroid hormone or hypophosphatemia.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 54
Correct
-
Which of the following clinical features would you NOT expect to see in a tibial nerve palsy:
Your Answer: Weakened eversion of the foot
Explanation:Damage to the tibial nerve results in loss of plantarflexion of the ankle and weakness of inversion of the foot resulting in a shuffling gait, clawing of the toes and loss of sensation in its cutaneous distribution.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 55
Correct
-
Anatomical barriers to infection include all of the following EXCEPT:
Your Answer: Mucociliary escalator in the gastrointestinal tract
Explanation:Anatomical barriers to infection include:tight junctions between cells of the skin and mucosal membranesthe flushing action of tears, saliva and urinethe mucociliary escalator in the respiratory tract (together with the actions of coughing and sneezing)the acidic pH of gastric and vaginal secretionsthe acidic pH of the skin (maintained by lactic acid and fatty acids in sebum)enzymes such as lysozyme found in saliva, sweat and tearspepsin present in the stomachbiological commensal flora formed on the skin and the respiratory, gastrointestinal and genitourinary tracts which protect the host by competing with pathogenic bacteria for nutrients and attachment sites and by producing antibacterial substances
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 56
Incorrect
-
Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Viral PCR
Correct Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 57
Incorrect
-
You've been summoned to a young man in the resus area who is experiencing an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.Which of the following is the correct adenosine mechanism of action?
Your Answer: Inhibits the Na/K ATPase in cardiac myocytes
Correct Answer: Opens K + channels in the heart
Explanation:The purine nucleoside adenosine is used to diagnose and treat paroxysmal supraventricular tachycardia. Adenosine works by stimulating A1-adenosine receptors and opening potassium channels that are sensitive to acetylcholine. This causes the atrioventricular (AV) node’s cell membrane to become hyperpolarized, slowing conduction by inhibiting calcium channels.Patients who have had a heart transplant are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg.Dipyridamole potentiates the effects of adenosine, so it should be used with caution in patients who are taking it.The use of adenosine is contraindicated in the following situations:AsthmaCOPD (chronic obstructive pulmonary disease)Decompensated heart failure Long QT syndromeAV block in the second or third degreeSinusitis is a condition in which the sinuses become (unless pacemaker fitted)Hypotension that is severe
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 58
Correct
-
A 40-year-old woman presents with a red, scaly, itchy rash around her navel that occurred after contact with a nickel belt buckle. A diagnosis of allergic contact dermatitis is made.Which type of hypersensitivity reaction is this?
Your Answer: Type IV hypersensitivity reaction
Explanation:A type IV hypersensitivity reaction occurred in this patient. Allergic contact dermatitis is an inflammatory skin reaction occurring in response to an external stimulus, acting either as an allergen or an irritant, caused by a type IV or delayed hypersensitivity reaction. They usually take several days to develop.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 59
Correct
-
An 80-year-old male has presented with chest pain characteristic of angina pectoris. Before initiating treatment with Glyceryl nitrate, you examine the patient and find a murmur. The patient reveals that he has a heart valve disorder, and you immediately put a hold on the GTN order.Which of the following valve disorders is an absolute contraindication to the use of GTN?
Your Answer: Mitral stenosis
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine. Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are: 1. Nitro-glycerine (NTG) – angina pectoris (treatment/prophylaxis), acute coronary syndrome, heart failure, hypertension2. Isosorbide mononitrate (ISMN) – chronic angina pectoris (treatment)3. Isosorbide dinitrate (ISDN) – angina pectoris (treatment/prophylaxis)The nitrate drugs cause vasodilation via the action of nitric oxide. The contraindications to the use of nitrate are the following: 1. Allergy to nitrates2. Concomitant use of phosphodiesterases (PDE) inhibitors such as tadalafil and sildenafil3. Right ventricular infarction4. Hypertrophic cardiomyopathy5. Cardiac tamponade6. Constrictive pericarditis7. Hypotensive conditions8. Hypovolaemia9. Marked anaemia10. Mitral stenosis11. Raised intracranial pressure due to cerebral haemorrhage or head trauma12. Toxic pulmonary oedema
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 60
Correct
-
A man presents to the emergency department with a hand laceration that has damaged the opponens digiti minimi muscle.All of the following statements regarding the opponens digiti minimi muscle is considered correct, except:
Your Answer: It is innervated by the superficial branch of the ulnar nerve
Explanation:Opponens digiti minimi (ODM) is an intrinsic muscle of the hand. It’s a triangular muscle that extends between the hamate bone (carpal bone) and the 5th metacarpal bone. It forms the hypothenar muscle group together with the abductor digiti minimi and flexor digiti minimi brevis, based on the medial side of the palm (hypothenar eminence). These muscles act together in moving the little finger. The opponens digiti minimi is responsible for flexion, lateral rotation and opposition of the little finger.Its origin is the hook of hamate and flexor retinaculum. It inserts into the medial border of 5th metacarpal bone. It is innervated by the deep branch of the ulnar nerve, which stems from the brachial plexus (C8, T1 spinal nerves).Its blood supply is by the deep palmar branch of ulnar artery and deep palmar arch, which is the terminal branch of the radial artery.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 61
Correct
-
Nitric oxide release from endothelium is stimulated by all of the following EXCEPT for:
Your Answer: Noradrenaline
Explanation:Nitric oxide (NO) production by the endothelium is increased by factors that elevate intracellular Ca2+, including local mediators such as bradykinin, histamine and serotonin, and some neurotransmitters (e.g. substance P). Increased flow (shear stress) also stimulates NO production and additionally activates prostacyclin synthesis. The basal production of NO continuously modulates vascular resistance; increased production of nitric oxide acts to cause vasodilation. Nitric oxide also inhibits platelet activation and thrombosis.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 62
Incorrect
-
Which of the following laboratory findings are suggestive of functional hyposplenism:
Your Answer: Rouleaux formation
Correct Answer: Howell-Jolly bodies
Explanation:Functional hyposplenism is characterised by the blood film findings of Howell-Jolly bodies or siderotic granules on iron staining. The most frequent cause is surgical removal of the spleen e.g. after traumatic rupture, but hyposplenism can also occur in sickle cell anaemia, gluten-induced enteropathy, amyloidosis and other conditions.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 63
Incorrect
-
A 12-year-old boy presents to you with a history of fever. A rash began as small red dots on the face, scalp, torso, upper arms and legs shortly afterwards and has now progressed to small blisters and pustules. You make a diagnosis of chickenpox.The following complications of chickenpox is the LEAST likely.
Your Answer: Orchitis
Correct Answer: Bronchospasm
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:OrchitisHepatitisPneumoniaEncephalitisInfected spotsOtitis mediaMyocarditisGlomerulonephritisAppendicitisPancreatitis
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 64
Correct
-
Which of the following statements is correct regarding flow through the cardiovascular system?
Your Answer: Turbulent blood flow may be caused by increased cardiac output.
Explanation:Frictional forces at the sides of a vessel cause a drag force on the fluid touching them in laminar blood flow, which creates a velocity gradient where the flow is greatest at the centre. Laminar blood flow may become disrupted and flow may become turbulent at high velocities, especially in large arteries or where the velocity increases sharply at points of sudden narrowing in the vessels, or across valves. There is increased tendency for thrombi formation when there is turbulent blood flow. Clinically, turbulence may be heard as a murmur or a bruit. As a result of elevated cardiac output, there may be turbulent blood flow, even when the cardiac valves are anatomically normal, and as a result, a physiological murmur can be heard. One such example is pregnancy.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 65
Correct
-
Langhans giant cells, seen in granulomatous inflammation. are:
Your Answer: Multinucleated cells formed from fusion of epithelioid cells
Explanation:A granuloma is a collection of five or more epithelioid macrophages, with or without attendant lymphocytes and fibroblasts; epithelioid macrophages are altered macrophages which have turned themselves over to becoming giant phagocytosing and killing machines, they often fuse to become multinucleate (Langhans) giant cells.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 66
Correct
-
A 25-year-old patient requires procedural sedation for reduction of an open fracture of his tibia and fibula. You plan on using ketamine as the sedative agent.Ketamine works as a result of action on what type of receptor? Select ONE answer only.
Your Answer: N-methyl-D-aspartate (NMDA)
Explanation:Ketamine is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties. When used correctly it is a very useful and versatile drug.Ketamine acts by non-competitive antagonism of the NMDA receptor Ca2+ channel pore and also inhibits NMDA receptor activity by interaction with the phencyclidine binding site.Ketamine can be used intravenously and intramuscularly. The intramuscular dose is 10 mg/kg, and when used by this route, it acts within 2-8 minutes and has a duration of action of 10-20 minutes. The intravenous dose is 1.5-2 mg/kg administered over a period of 60 seconds. When used intravenously, it acts within 30 seconds and has a duration of action of 5-10 minutes. Ketamine is also effective when administered orally, rectally, and nasally.Ketamine causes tachycardia, an increase in blood pressure, central venous pressure, and cardiac output, secondary to an increase in sympathetic tone. Baroreceptor function is well maintained, and arrhythmias are uncommon.The main disadvantage to the use of ketamine is the high incidence of hallucinations, nightmares, and other transient psychotic effects. These can be reduced by the co-administration of a benzodiazepine, such as diazepam or midazolam.The main side effects of ketamine are:Nausea and vomitingHypertensionNystagmusDiplopiaRash
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 67
Correct
-
Question 68
Incorrect
-
A patient with a wound infection on his right leg has reddening and oedema of the surrounding muscles. His condition has worsened considerably over the past few hours with the area now appearing blackened. There is also palpable crepitus under the skin. You suspect gas gangrene.Which statement about Clostridium perfringens is true?
Your Answer: The clinical features of gas gangrene typically appear 7 days after injury
Correct Answer: Gas gangrene is caused by the release of an alpha-toxin
Explanation:Clostridium perfringens, a Gram-positive, anaerobic, spore forming rod-shaped, pathogenic bacterium is the most commonly associated with gas gangrene (85-90% of cases), although other species can also be implicated. Clostridium perfringens is capsulate and produces a range of toxins. Alpha-toxin is the most important and is the cause of gas gangrene.Gas gangrene develops when a devitalized wound becomes infected with Clostridium perfringens spores from the environment. The spores germinate and multiplies in the ischaemic conditions, releasing toxins, which further damage tissues.Usually, the clinical features of gas gangrene appear within 24 hours of injury.Clostridium perfringens spores are not destroyed by cooking. During slow cooling and unrefrigerated storage, they germinate to form vegetative cells.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 69
Incorrect
-
A 32-year-old female is diagnosed case of bipolar disorder and is on medication. She presents to her psychiatric team with symptoms of severe depression. She is currently taking Lithium. Out of the following, which is TRUE regarding lithium?
Your Answer: It can induce diabetes mellitus
Correct Answer: It commonly causes a tremor
Explanation:Lithium is the drug of choice for bipolar disorders but is commonly associated with side effects and toxicity. Fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy with Lithium. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer. Lithium tremors are more common with older age, presumably due to the additive effects of age-related essential tremors.Option The normal therapeutic range is 2.0-2.5 mmol/l: Lithium should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l. Levels should be checked one week after starting therapy and one week after every change in dosage. (Option Levels should be checked one month after starting therapy) Option It can induce hyperthyroidism: Lithium has a known effect on thyroid function. Lithium decreases the production of T4 and T3 and commonly causes hypothyroidism. More rarely, lithium causes hyperthyroidism due to thyroiditis.Option It can induce diabetes mellitus: Lithium can induce nephrogenic diabetes insipidus but not diabetes mellitus.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 70
Correct
-
Regarding cross-sectional studies, which of the following statements is CORRECT:
Your Answer: They are particularly suitable for estimating point prevalence.
Explanation:Cross-sectional studies aim to provide data about population health, normal ranges of biological parameters, and disease prevalence or severity by observing the entire population, or a representative subset, at a single point in time. Cross-sectional studies are relatively simple and quick to perform and can be used to study multiple outcomes, but are subject to confounding and recall bias and are not suitable for studying rare diseases. Cross-sectional studies cannot be used to assess causation or to consider trends over time.
-
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
-
-
Question 71
Correct
-
A patient presents with a history of renal problems, generalised weakness and palpitations. Her serum potassium levels are measured and come back at 6.2 mmol/L. An ECG is performed, and it shows some changes that are consistent with hyperkalaemia.Which of the following ECG changes is usually the earliest sign of hyperkalaemia? Select ONE answer only.
Your Answer: Peaked T waves
Explanation:Hyperkalaemia causes a rapid reduction in resting membrane potential leading to increased cardiac depolarisation and muscle excitability. This in turn results in ECG changes which can rapidly progress to ventricular fibrillation or asystole. Very distinctive ECG changes that progressively change as the K+level increases:K+>5.5 mmol/l – peaked T waves (usually earliest sign of hyperkalaemia), repolarisation abnormalitiesK+>6.5 mmol/l – P waves widen and flatten, PR segment lengthens, P waves eventually disappearK+>7.0 mmol/l – Prolonged QRS interval and bizarre QRS morphology, conduction blocks (bundle branch blocks, fascicular blocks), sinus bradycardia or slow AF, development of a sine wave appearance (a pre-terminal rhythm)K+>9.0 mmol/l – Cardiac arrest due to asystole, VF or PEA with a bizarre, wide complex rhythm.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 72
Incorrect
-
A 18-year-old man returns from a trip to Ibiza with a severely painful left eye. He has copious mucopurulent discharge, is febrile and has left-sided tender preauricular lymphadenopathy. He attends the local eye casualty and is diagnosed with hyperacute conjunctivitis.What is the SINGLE most likely causatiave organism?
Your Answer: Chlamydia trachomatis
Correct Answer: Neisseria gonorrhoeae
Explanation:Hyperacute bacterial conjunctivitis is a severe, sight-threatening ocular infection that warrants immediate ophthalmic work-up and management. The infection has an abrupt onset and is characterized by a copious yellow-green purulent discharge that reaccumulates after being wiped away. Typically caused by infection with Neisseria gonorrhoeae.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 73
Correct
-
A 36-year-old man presented to the emergency room after an incident of slipping and falling onto his back and left hip. Upon physical examination, it was noted that he has pain on hip extension, but normal hip abduction. Which of the following muscles was most likely injured in this case?
Your Answer: Gluteus maximus
Explanation:The primary hip extensors are the gluteus maximus and the hamstrings such as the long head of the biceps femoris, the semitendinosus, and the semimembranosus. The extensor head of the adductor magnus is also considered a primary hip extensor.The hip abductor muscle group is located on the lateral thigh. The primary hip abductor muscles include the gluteus medius, gluteus minimus, and tensor fasciae latae.The secondary hip abductors include the piriformis, sartorius, and superior fibres of the gluteus maximus.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 74
Correct
-
Regarding Legionella species which of the following statements is CORRECT:
Your Answer: They are Gram-negative organisms.
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 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella 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
- Pathogens
-
-
Question 75
Correct
-
What is the primary route of transmission of Neisseria Gonorrhoeae?
Your Answer: Sexually transmitted
Explanation:Neisseria gonorrhoeae is primarily spread by sexual contact or through transmission during childbirth. It causes gonorrhoea which is a purulent infection of the mucous membrane surfaces.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 76
Correct
-
Which of the following could denote a diagnosis of acquired immunodeficiency syndrome (AIDS) in a patient infected with HIV:
Your Answer: CD4 count < 200 cells/uL
Explanation:A diagnosis of AIDS can be made in a patient infected with HIV if the patient has a CD4 count < 200 cells/uL, or an AIDS-defining illness. Antiretroviral treatment should be considered in patients with CD4 counts < 350 cells/uL. Oral candidiasis is not an AIDS defining illness – candidiasis of the bronchi, trachea or lungs or of the oesophagus is an AIDS defining illness. A positive p24 antigen test seen in early HIV infection and does not indicate the development of AIDS.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 77
Correct
-
A 42-year-old male patient, presenting with polyuria and polydipsia symptoms had normal blood test results. Upon interview, he had mentioned being in a car accident in which he had a head injury. His polyuria and polydipsia symptoms are most likely associated with which of the following conditions?
Your Answer: Cranial diabetes insipidus
Explanation:Polydipsia is the feeling of extreme thirstiness. It is often linked to polyuria, which is a urinary condition that causes a person to urinate excessively. The cycle of these two processes makes the body feel a constant need to replace the fluids lost in urination. In healthy adults, a 3 liter urinary output per day is considered normal. A person with polyuria can urinate up to 15 liters of urine per day. Both of these conditions are classic signs of diabetes. The other options are also types of diabetes, except for psychogenic polydipsia (PPD), which is the excessive volitional water intake seen in patients with severe mental illness or developmental disability. However, given the patient’s previous head injury, the most likely diagnosis is cranial diabetes insipidus. By definition, cranial diabetes insipidus is caused by damage to the hypothalamus or pituitary gland after an infection, operation, brain tumor, or head injury. And the patient’s history confirms this diagnosis. To define the other choices, nephrogenic diabetes insipidus happens when the structures in the kidneys are damaged and results in an inability to properly respond to antidiuretic hormone. Kidney damage can be caused by an inherited (genetic) disorder or a chronic kidney disorder. As with cranial diabetes insipidus, nephrogenic diabetes insipidus can also cause an elevated urine output. Diabetes mellitus is classified into two types, and the main difference between them is that type 1 diabetes is a genetic disorder, and type 2 diabetes is diet-related and develops over time. Type 1 diabetes is also known as insulin-dependent diabetes, in which the pancreas produces little or no insulin. Type 2 diabetes is termed insulin resistance, as cells don’t respond customarily to insulin.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 78
Correct
-
Pressure across the wall of a flexible tube (the transmural pressure) increases wall tension and extends it.Which law best describes transmural pressure?
Your Answer: Laplace’s law
Explanation:The transmural pressure (pressure across the wall of a flexible tube) can be described by Laplace’s law which states that:Transmural pressure = (Tw) / rWhere:T = Wall tensionw = Wall thicknessr = The radiusA small bubble with the same wall tension as a larger bubble will contain higher pressure and will collapse into the larger bubble if the two meet and join.Fick’s law describes the rate of diffusion in a solutionPoiseuille’s law is used to calculate volume of flow rate in laminar flowDarcy’s law describes the flow of a fluid through a porous medium.Starling’s law describes cardiac haemodynamics as it relates to myocyte contractility and stretch.
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 79
Correct
-
A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.At the moment, he is completely symptom-free. When it comes to this type of overdose, how long does it usually take for symptoms to appear?
Your Answer: 1-2 hours
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.>10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem can cause serious toxicity (180 mg, 240 mg or 360 mg immediate or sustained-release capsules)In children, 1-2 tablets of verapamil or diltiazem (immediate or sustained-release)Symptoms usually appear within 1-2 hours of ingestion with standard preparations. However, with slow-release preparations, significant toxicity may take 12-16 hours to manifest, with peak effects occurring after 24 hours.The following are the main clinical features of calcium-channel blocker overdose:Nausea and vomitingHypotensionBradycardia and first-degree heart blockMyocardial ischaemia and strokeRenal failurePulmonary oedemaHyperglycaemiaThe following are some of the most important bedside investigations to conduct:Blood glucoseECGArterial blood gasOther investigations that can be helpful includeUrea & electrolytesChest X-ray (pulmonary oedema)Echocardiography
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 80
Correct
-
Question 81
Incorrect
-
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: Loss of tongue movements
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.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 82
Correct
-
Which of the following leukaemias is most common in children in the UK:
Your 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.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 83
Correct
-
Platelet alpha granules release which of the following?
Your Answer: Von Willebrand factor (VWF)
Explanation:There are three types of storage granules contained in platelets. These are dense granules which contain the following:-ATP -ADP -serotonin and calcium alpha granules containing clotting factors-von Willebrand factor (VWF)-platelet-derived growth factor (PDGF)- other proteins lysosomes containing hydrolytic enzymes.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 84
Incorrect
-
A 75-year-old man with rheumatoid arthritis had gained weight, developed resistant hypertension, muscle weakness, and ankle oedema. This patient is most likely suffering from what condition?
Your Answer: Pheochromocytoma
Correct Answer: Cushing's syndrome
Explanation:Overuse of cortisol medication, as seen in the treatment of patients with chronic asthma or rheumatoid arthritis, can cause Cushing’s syndrome. Weight gain, thin arms and legs, a round face, increased fat around the base of the neck, a fatty hump between the shoulders, easy bruising, wide purple stretch marks primarily on the abdomen, breasts, hips, and under the arms, weak muscles, hirsutism, hypertension, erectile dysfunction, osteoporosis, frontal alopecia, acne, depression, poor wound healing, and polycythaemia are all clinical features of Cushing’s syndrome.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 85
Correct
-
Insulin is produced by which of the following pancreatic cells:
Your Answer: β cells
Explanation:Insulin is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. Insulin is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. Proinsulin is synthesised as a single-chain peptide. Within storage granules, a connecting peptide (C peptide) is removed by proteases to yield insulin. Insulin release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin, but most output is driven by the rise in plasma glucose concentration that occurs after a meal. The effects of insulin are mediated by the receptor tyrosine kinase.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 86
Correct
-
Which of the following does NOT increase free ionised calcium levels:
Your Answer: Calcitonin
Explanation:Calcium homeostasis is primarily controlled by three hormones: parathyroid hormone, activated vitamin D and calcitonin.Parathyroid hormone acts on the kidneys to increase calcium reabsorption in the distal tubule by activating Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane (and to decrease phosphate reabsorption in the proximal tubule).Activated vitamin D acts to increase calcium reabsorption in the distal tubule via activation of a basolateral Ca2+ATPase pump (and to increase phosphate reabsorption).Calcitonin acts to inhibit renal reabsorption of calcium (and phosphate).
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 87
Correct
-
Foetal haemoglobin (HbF) comprises about how much of the total haemoglobin in adults:
Your Answer: 0.5 - 0.8%
Explanation:Foetal haemoglobin (HbF) makes up about 0.5 – 0.8 % of total adult haemoglobin and consists of two α and two gamma (γ) globin chains.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 88
Incorrect
-
The lymph drainage of the anal canal above the pectinate line is initially to the:
Your Answer: Deep inguinal nodes
Correct Answer: Internal iliac nodes
Explanation:Above the pectinate line, the anal canal drains to the internal iliac lymph nodes which subsequently drain to the lumbar (para-aortic) nodes.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 89
Incorrect
-
A 45-year-old African American male presents to your clinic complaining of swelling of his feet for the past six months. On examination, there is periorbital and pedal oedema. A 24-hour urine collection is ordered, which shows 8 g of protein. The serum cholesterol is ten mmol/L. You order a renal biopsy to confirm the diagnosis. Which one of the following findings are you most likely to see in this patient's biopsy?
Your Answer: IgA nephropathy
Correct Answer: Focal segmental glomerulosclerosis
Explanation:This patient has Nephrotic Syndrome confirmed by the presence of 1. Heavy proteinuria (greater than 3-3.5 g/24 hours)2. Hypoalbuminemia (serum albumin < 25 g/L)3. Generalised oedema (often with periorbital involvement)4. Severe hyperlipidaemia (total cholesterol is often > 10 mmol/L). Focal Segmental Glomerulosclerosis will be the most likely answer as it is the most common cause of Nephrotic Syndrome in African American adults. Minimal change disease is the most common cause of nephrotic syndrome in children. Membranous glomerulonephritis is the most common cause of Nephrotic Syndrome in Caucasian adults. In IgA nephropathy, patients will complain of cola-coloured urine. Mesangiocapillary glomerulonephritis presents with features of Nephritic Syndrome.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 90
Correct
-
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 NOTÂ true?Â
Your 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.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 91
Correct
-
A 45-year-old woman presents with persistent palpitations for the past two days. She has a good haemodynamic balance. An ECG is performed, which reveals that she has atrial flutter. The patient is examined by a cardiology registrar, who recommends using a 'rate control' strategy while she waits for cardioversion.Which of the drugs listed below is the best fit for this strategy?
Your Answer: Bisoprolol
Explanation:In atrial flutter, ventricular rate control is usually used as a stopgap measure until sinus rhythm can be restored. A beta-blocker (such as bisoprolol), diltiazem, or verapamil can be used to lower the heart rate.Electrical cardioversion, pharmacological cardioversion, or catheter ablation can all be used to restore sinus rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or has lasted for more than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is an acute presentation with haemodynamic compromise. For the treatment of recurrent atrial flutter, catheter ablation is preferred.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 92
Incorrect
-
All of the following predisposes to lithium toxicity in patients taking long-term therapy EXCEPT:
Your Answer: Infections
Correct Answer: Hypernatraemia
Explanation:A common complication of long term lithium therapy results in most cases of lithium intoxication. It is caused by reduced excretion of the drug which can be due to several factors including deterioration of renal function, dehydration, hyponatraemia, infections, and co-administration of diuretics or NSAIDs or other drugs that may interact.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 93
Correct
-
Eosinophils comprise what percentage of circulating white cells:
Your Answer: 1 - 3%
Explanation:Eosinophils comprise 1 – 3% of circulating white cells. Eosinophils are similar to neutrophils, except that the cytoplasmic granules are coarser and more deeply red staining, and there are rarely more than three nuclear lobes. They are less motile, but longer lived. They enter inflammatory exudates and have a special role in allergic responses, defence against parasites and removal of fibrin formed during inflammation. Thus they play a role in local immunity and tissue repair.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 94
Correct
-
A 53-year-old male has presented to your clinic with the complaint of a rash on his right forearm. On examination, you discover small reddish-purple spots on the skin measuring less than 2-3 mm. They do not blanch on applying pressure. Which one of the following best fits the description given above?
Your Answer: Petechiae
Explanation:Petechiae are small red or purple spots on the skin measuring less than 3 mm, caused by minor haemorrhages which do not blanch on applying pressure.Purpura measures between 3mm and 1 cm in diameter, while ecchymoses are greater than 1 cm in diameter. Both are caused due to haemorrhage. Erythema is the generalised redness of the skin. A macule is a flat, discoloured area of the skin measuring less than 1 cm in diameter.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 95
Correct
-
Approximately what proportion of lymphocytes are B-cells:
Your Answer: 0.2
Explanation:B-cells (20% of lymphocytes) mature in the bone marrow and circulate in the peripheral blood until they undergo recognition of antigen. B-cell immunoglobulin molecules synthesised in the cell are exported and bound to the surface membrane to become the B-cell receptor (BCR) which can recognise and bind to a specific antigen (either free or presented by APCs). The BCR is also important for antigen internalisation, processing and presentation to T helper cells. Most antibody responses require help from antigen-specific T helper cells (although some antigens such as polysaccharide can lead to T-cell independent B-cell antibody production). When the B-cell is activated, the receptor itself is secreted as free soluble immunoglobulin and the B-cell matures into a memory B-cell or a plasma cell (a B-cell in its high-rate immunoglobulin secreting state). Plasma cells are non-motile and are found predominantly in the bone marrow or spleen. Most plasma cells are short-lived (1 – 2 weeks) but some may survive much longer. A proportion of B-cells persist as memory cells, whose increased number and rapid response underlies the augmented secondary response of the adaptive immune system.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 96
Incorrect
-
When treating diabetic ketoacidosis (DKA), glucose should be given together with insulin as soon as the blood glucose concentration falls below 14 mmol/L in the form of:
Your Answer: 10% glucose intravenous infusion at a rate of 250 mL/hour
Correct Answer: 10% glucose intravenous infusion at a rate of 125 mL/hour
Explanation:In addition to the sodium chloride 0.9 percent infusion, glucose 10% should be given intravenously (into a large vein with a large-gauge needle) at a rate of 125 mL/hour once blood glucose concentration falls below 14 mmol/litre.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 97
Correct
-
A 28-year-old asthmatic patient is seen in the Emergency Department following an acute exacerbation. His symptoms start to improve when your consultant gives him a high dose of IV aminophylline.Which of the following is correct mechanism of action of aminophylline ?
Your Answer: Inhibition of phosphodiesterase
Explanation:Aminophylline has the following properties:Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 98
Correct
-
Which of the following is NOT a typical side effect of thiopental sodium:
Your Answer: Seizures
Explanation:Extravasation of thiopental during injection can lead to tissue damage. Accidental intra-arterial injection causes vasospasm and may lead to thrombosis and tissue necrosis. Other side effects include involuntary muscle movements on induction, cough and laryngospasm, arrhythmias, hypotension, headache and hypersensitivity reactions. Thiopental sodium has anticonvulsant properties and does not cause seizures.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 99
Incorrect
-
Regarding linear relationships between two variables, what does a positive correlation coefficient indicate:
Your Answer: There is strong correlation between two variables
Correct Answer: The two variables are directly proportional
Explanation:A positive correlation coefficient means that the two variables are directly proportional e.g. height and weight in healthy growing children.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 100
Correct
-
Regarding hepatitis B, which of the following statements is CORRECT:
Your Answer: Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months.
Explanation:Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months. Hepatitis B has a long incubation period of about 2 – 6 months. Hepatitis B vaccine has recently been introduced to the routine childhood immunisation schedule – given at 2, 3 and 4 months. It is also given to babies born to hepatitis B infected mothers at birth, four weeks and 12 months old. Treatment of acute hepatitis is supportive. Treatment with antivirals should be considered in chronic infection as responders have a reduced risk of liver damage and liver cancer in the long term.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
SESSION STATS - PERFORMANCE PER SPECIALTY
