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Question 1
Incorrect
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Which of the following is NOT a function of antibodies:
Your Answer: Opsonise antigens for phagocytosis
Correct Answer: Act as antigen receptors on T lymphocytes
Explanation:Antibodies: Neutralise toxins and prevent attachment of pathogensTarget, opsonise or agglutinate (clump together) antigens for phagocytosisActivate the complement cascade (leading to lysis or opsonisation of the pathogen)Act as antigen receptors on B lymphocytesActivate antibody-dependent cell-mediated cytotoxicity by natural killer (NK) cells or T cytotoxic cellsProvide mucosal immunity (IgA-mediated)Stimulate degranulation of mast cells (IgE and IgG mediated)Provide passive immunity to the newborn (through transplacental passage of IgG and secretion of IgA in breast milk)
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 2
Correct
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Bordetella pertussis causes which of the following infectious diseases:
Your Answer: Whooping cough
Explanation:Bordetella pertussis causes whooping cough. Acute bronchiolitis is typically caused by respiratory syncytial virus. Parainfluenza virus is the most common cause of croup. Acute epiglottitis is usually caused by an infection with Haemophilus influenzae type b (Hib) bacteria. The common cold may be caused by a number of viruses including rhinovirus and coronavirus.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 3
Correct
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A medical student is reviewing the chart of a patient who has recently been diagnosed with leukaemia. The chief resident asks him to identify ONE feature that will most support acute leukaemia diagnosis in contrast to chronic leukaemia. Which one of the following options will he pick?
Your Answer: The patient is a child
Explanation:Acute lymphocytic leukaemia (ALL) is more common in children than chronic leukaemias, which generally occur in adults. Bone marrow failure occurs early on in the course of the disease in acute leukaemias, and there is the massive proliferation of undifferentiated cells with functioning cells being crowded out. Hepatosplenomegaly occurs in both acute and chronic forms of leukaemia and is not a differentiating feature.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 4
Correct
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A 60-year-old patient with a history of hypertension and chronic kidney disease (CKD) walks into the clinic to discuss her most recent blood results indicating an accelerated progression of CKD.Which of the following is the correct definition for accelerated progression of CKD?
Your Answer: A sustained decrease in GFR of 15 ml/minute/1.73 m 2 per year
Explanation:Chronic kidney disease (CKD) is a disorder in which kidney function gradually deteriorates over time. It’s fairly prevalent, and it typically remains unnoticed for years, with only advanced stages of the disease being recognized. There is evidence that medication can slow or stop the progression of CKD, as well as lessen or prevent consequences and the risk of cardiovascular disease (CVD).CKD is defined as kidney damage (albuminuria) and/or impaired renal function (GFR 60 ml/minute per 1.73 m2) for three months or longer, regardless of clinical diagnosis.A prolonged decline in GFR of 25% or more with a change in GFR category within 12 months, or a sustained drop in GFR of 15 ml/minute/1.73 m² per year, is considered accelerated CKD progression.End-stage renal disease (ESRD) is defined as severe irreversible kidney impairment with a GFR of less than 15 ml/minute per 1.73 m² and a GFR of less than 15 ml/minute per 1.73 m².
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 5
Correct
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A patient presents with nausea, anorexia, jaundice and right upper quadrant pain. A diagnosis of acute hepatitis B is suspected.Which of the following blood results is most suggestive of an acute hepatitis B infection? Select ONE answer only.
Your Answer: HBsAg positive, IgM anti-HBc positive
Explanation:Hepatitis B surface antigen (HBsAg) is a protein on the surface of the hepatitis B virus, that is the first serologic marker to appear in a new acute infection.It can be detected as early as 1 week and as late as 9 weeks. It can be detected in high levels in serum during acute or chronic hepatitis B virus infection. The presence of HBsAg indicates that the person is infectious. The body normally produces antibodies to HBsAg as part of the normal immune response to infection. HBsAg is the antigen used to make hepatitis B vaccine.Hepatitis B surface antibody (anti-HBs) indicates recovery and immunity from the hepatitis B virus infection. Anti-HBs also develops in a person who has been successfully vaccinated against hepatitis B.Total hepatitis B core antibody (anti-HBc): Appears at the onset of symptoms in acute hepatitis B and persists for life. The presence of anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined time frame. It is not present following hepatitis B vaccination.IgM antibody to hepatitis B core antigen (IgM anti-HBc) indicates recent infection with hepatitis B virus (<6 months). Its presence indicates acute infection.The following table summarises the presence of hepatitis B markers according to each situation:Susceptible to infection:HBsAg = NegativeAnti-HBc = NegativeAnti-HBs = NegativeImmune due to natural infection:HBsAg = NegativeAnti-HBc = PositiveAnti-HBs = PositiveImmune due to vaccination:HBsAg = NegativeAnti-HBc = NegativeAnti-HBs = PositiveAcute infection:HBsAg = PositiveAnti-HBc = PositiveAnti-HBs = NegativeIgM anti-HBc = PositiveChronic infection:HBsAg = PositiveAnti-HBc = PositiveAnti-HBs = NegativeIgM anti-HBc = Negative
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 6
Incorrect
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A 60-year-old female with a past history of rheumatic fever and a prosthetic mitral valve presents to you with fever and an episode of expressive dysphasia that lasted around 30 minutes. There is no history of known drug allergies On examination you note a systolic murmur and you suspect it is infective endocarditis.Which antibacterial agents would be the most appropriate to prescribe in this case?
Your Answer: Vancomycin, rifampicin and metronidazole
Correct Answer: Vancomycin, rifampicin and gentamicin
Explanation:Endocarditis is infective or non infective inflammation (marantic endocarditis) of the inner layer of the heart and it often involves the heart valves.Risk factors include:Prosthetic heart valvesCongenital heart defectsPrior history of endocarditisRheumatic feverIllicit intravenous drug useIn the presentation of endocarditis, the following triad is often quoted:Persistent feverEmbolic phenomenaNew or changing murmurA combination of vancomycin, rifampicin and gentamicin is advised if the patient has a cardiac prostheses, is penicillin allergic, or if methicillin-resistant Staphylococcus aureus (MRSA) is suspected. In this case the patient has a prosthetic valve making this the most appropriate initial treatment regimen.Flucloxacillin and gentamicin are current recommended by NICE and the BNF for the initial ‘blind’ therapy in endocarditis. This patient has prostheses and this is not the most appropriate initial treatment regimen.Other features that may be present include heart failure, splenomegaly, finger clubbing, renal features (haematuria, proteinuria, nephritis), and vasculitic features (splinter haemorrhages, Osler’s nodes, Janeway lesions, Roth’s spots).
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 7
Correct
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A patient suffers from an injury and as a consequence, the nerve that was damaged innervates the obturator internus muscle.In which of the following nerves is the obturator internus muscle innervated by?
Your Answer: Nerve to obturator internus
Explanation:The obturator internus is innervated by the obturator internus nerve (L5–S2), a branch of sacral plexus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 8
Incorrect
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Cardiac myocytes contract by excitation-contraction coupling, very much like skeletal myocytes. On the other hand, calcium-induced calcium release (CICR) is a mechanism that is unique to Cardiac myocytes. The influx of calcium ions (Ca 2+) into the cell causes a 'calcium spark,' which causes more ions to be released into the cytoplasm.In CICR, which membrane protein in the sarcoplasmic reticulum is involved?Â
Your Answer: Sarcoplasmic and endoplasmic reticulum ATP-ase
Correct Answer: Ryanodine receptor
Explanation: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.The release of Ca2+ from the sarcoplasmic reticulum is required for calcium-induced calcium release (CICR). This is mostly accomplished by ryanodine receptors (RyR) on the sarcoplasmic reticulum membrane; Ca2+ binds to RyR, causing additional Ca2+ to be released.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 9
Correct
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External haemorrhoids may cause anal pain. When explaining to your patient why it does so, which of the following nerves will you point out as being affected?
Your Answer: Pudendal nerve
Explanation:The pain associated with external haemorrhoids is carried by a branch of the pudendal nerve, specifically the somatic fibres (S2-S4). It innervates the external anal sphincter and most of the skin over the perineum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 10
Correct
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All of the following typically occurs as part of normal inspiration except:
Your Answer: Contraction of the internal intercostal muscles
Explanation:Passive inspiration is a result of contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs). In inspiration, several movements occur. These are:1. elevation of the sternal ends of the ribs (‘pump handle’ movement), 2. elevation of the lateral shafts of the ribs (‘bucket handle’ movement) 3. depression of the diaphragm. These result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. There is an increased intrathoracic volume and decreased intrathoracic pressure and air is drawn into the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 11
Correct
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In inserting a nasogastric tube, which area is least likely to be a site of resistance when the tube goes from the nose to the stomach?
Your Answer: In the posterior mediastinum where the oesophagus is crossed by the pulmonary trunk
Explanation:In the posterior mediastinum where the oesophagus is crossed by the pulmonary trunk offers the least resistance when nasogastric tube is inserted from the nose to the stomach.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 12
Correct
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A 10-year-old girl that appears systemically well presents with a honey-crusted scab close to the corner of her mouth and states that the area is slightly itchy but not painful. The diagnosis given was impetigo.What is most likely the mode of transmission of the causative agent of the said diagnosis?
Your Answer: Direct contact
Explanation:Impetigo is a common pyoderma that is most often seen in children. Historically, most cases were caused by group A streptococci (GAS; Streptococcus pyogenes), although S. aureus has become the predominant pathogen over the last 15 years.A bullous form of impetigo accounts for approximately 10% of cases. It is caused by strains of S. aureus that produce exfoliative toxins leading to the formation of bullae, which quickly rupture and form a transparent, light brown crust.Impetigo is spread mainly by person-to-person contact; it is rapidly spread through direct transmission. The diagnosis of impetigo can be made from a Gram stain and culture of the vesicular contents.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 13
Incorrect
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The following statements about leukotrienes as chemical mediators of the acute inflammatory response are all true EXCEPT?
Your Answer: They are synthesised from arachidonic acid
Correct Answer: They decrease vascular permeability
Explanation:Leukotrienes increases (not decrease) vascular permeability during acute inflammation.All the other statements are correct
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 14
Correct
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Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis. At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine. Muscle paralysis occurs gradually due to the competitive blockade.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 15
Correct
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The following are all important buffers of H+EXCEPT for:
Your Answer: Calcium
Explanation:Buffers are weak acids or bases that can donate or accept H+ions respectively and therefore resist changes in pH. Buffering does not alter the body’s overall H+load, ultimately the body must get rid of H+by renal excretion if the buffering capacity of the body is not to be exceeded and a dangerous pH reached. Bicarbonate and carbonic acid (formed by the combination of CO2 with water, potentiated by carbonic anhydrase) are the most important buffer pair in the body, although haemoglobin provides about 20% of buffering in the blood, and phosphate and proteins provide intracellular buffering. Buffers in urine, largely phosphate, allow the excretion of large quantities of H+.
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This question is part of the following fields:
- Physiology
- Renal
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Question 16
Correct
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A 25 year old man has sustained a fracture to the surgical neck of the humerus after falling from his bike. Examination suggests an axillary nerve injury. The clinical features expected to be seen in this patient are:
Your Answer: Weakness of shoulder abduction
Explanation:Axillary nerve injury results in:1. weakness of arm abduction (paralysis of deltoid), 2. weakness of lateral rotation of the arm (paralysis of teres minor) 3. loss of sensation over the regimental badge area.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 17
Correct
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After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.The nerve injured in the case above is?
Your Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 18
Correct
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Regarding the human cell, which of the following cell organelles is responsible for the production of ATP:
Your Answer: Mitochondria
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 19
Incorrect
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A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?
Your Answer: Sensitivity
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 20
Correct
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Question 21
Incorrect
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Which of the following features of cell damage tends to be reversible:
Your Answer: Membrane blebs and holes
Correct Answer: Swelling of endoplasmic reticulum and some mitochondria
Explanation:Features of cell damage that tend to be reversible include: swelling of endoplasmic reticulum and some mitochondrialoss of ribosomescell stress responseFeatures of cell damage that tend to be irreversible include: loss of nucleolus, no ribosomes, swelling of all mitochondria, nuclear condensation, membrane blebs and holes, lysosome rupture, fragmentation of all inner membranes, nuclear breakup
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 22
Incorrect
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In the Emergency Department, a 35-year-old woman actively seizing is brought in. She is quickly shifted into the resuscitation room and is administered a dose of benzodiazepine. The seizure is quickly terminated. Once the patient is stable, she tells you she is a known case of epilepsy and takes phenytoin to control it. Which of the following is the primary mechanism of action of phenytoin?
Your Answer: GABA receptor agonist
Correct Answer: Sodium channel blocker
Explanation:Phenytoin is in the anticonvulsants class of drugs and is used in the management and treatment of the following:1. epilepsy2. generalized tonic-clonic seizures3. complex partial seizures4. status epilepticus. It works by inactivating the voltage-gated sodium channels responsible for increasing the action potential. It is non-specific and targets almost all voltage-gated sodium channel subtypes. More specifically, phenytoin prevents seizures by inhibiting the positive feedback loop that results in neuronal propagation of high-frequency action potentials.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 23
Correct
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Stimulation of J receptors located on alveolar and bronchial walls results in all of the following EXCEPT for:
Your Answer: Tachycardia
Explanation:Juxtapulmonary or ‘J’ receptors are located on alveolar and bronchial walls close to the capillaries. Their afferents are small unmyelinated C-fibres or myelinated nerves in the vagus nerve. Activation causes depression of somatic and visceral activity by producing apnoea or rapid shallow breathing, a fall in heart rate and blood pressure, laryngeal constriction and relaxation of skeletal muscles via spinal neurones. J receptors are stimulated by increased alveolar wall fluid, pulmonary congestion and oedema, microembolism and inflammatory mediators. J receptors are thought to be involved in the sensation of dyspnoea in lung disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 24
Correct
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You suspected typhoid disease in a patient who had recently returned from South America and presented to the emergency department with fever, constipation, and a rose spot rash. Which of the following antibiotics will be administered to this patient?
Your Answer: Cefotaxime
Explanation:Typhoid fever, often known as enteric fever, is a potentially fatal multi-systemic sickness caused predominantly by Salmonella enterica serotype typhi and, to a lesser extent, paratyphi A, B, and C. Cefotaxime is the first-line treatment for typhoid fever (or ceftriaxone). In cases of mild or moderate sickness caused by multiresistant pathogens, azithromycin is an option. If the bacterium is sensitive, ciprofloxacin is an option.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 25
Incorrect
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You are about to perform a blood test on a patient suspected of having systemic lupus erythematosus. Which antibodies will indicate a positive result of systemic lupus erythematosus?
Your Answer: Antiphospholipid antibodies
Correct Answer: Anti-nuclear antibodies
Explanation:Antinuclear antibodies (ANA) are autoantibodies to the cells’ nucleus. The ANA test is the most sensitive diagnostic test for verifying the disease’s diagnosis. Other autoantibodies that may be found in SLE patients include rheumatoid factor, antiphospholipid antibodies, and antimitochondrial antibodies.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 26
Correct
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A 5-year-old girl presents in a paediatric clinic with symptoms of viral gastroenteritis. You encourage the mother to treat the child at home with oral rehydration therapy (ORT), e.g. dioralyte.Out of the following, which statement is FALSE regarding the use of ORT in the management of gastroenteritis?
Your Answer: ORT is sugar-free
Explanation:One of the major complications of gastroenteritis is dehydration. Choosing the correct fluid replacement therapy is essential according to a patient’s hydration status. Oral rehydration therapy (ORT) refers to the restitution of water and electrolyte deficits in dehydrated patients using an oral rehydration salt (ORS) solution. It is a fluid replacement strategy that is less invasive than other strategies for fluid replacement and has successfully lowered the mortality rate of diarrhoea in developing countries. Some characteristics of Oral rehydration solutions are:- slightly hypo-osmolar (about 250 mmol/litre) to prevent the possible induction of osmotic diarrhoea.- contain glucose (e.g. 90 mmol/L in dioralyte). The addition of glucose improves sodium and water absorption in the bowel and prevents hypoglycaemia. – also contains essential mineral saltsCurrent NICE guidance recommends that 50 ml/kg is given over 4 hours to treat mild dehydration.Once rehydrated, a child should continue with their usual daily fluid intake plus 200 ml ORT after each loose stool. In an infant, give ORT at 1-1.5 x the normal feed volume and in an adult, give 200-400 ml after each loose stool.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pharmacology
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Question 27
Correct
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Which of the following best describes a natural killer cell:
Your Answer: A large granular lymphocyte that kills by inducing target cell apoptosis.
Explanation:Natural killer (NK) cells are cytotoxic CD8 positive cells that lack the T-cell receptor. They are large cells with cytoplasmic granules. NK cells are designed to kill target cells that have a low level of expression of HLA class I molecules, such as may occur during viral infection or on a malignant cell. NK cells do this by displaying several receptors for HLA molecules on their surface. When HLA is expressed on the target cell these deliver an inhibitory signal into the NK cell. When HLA molecules are absent on the target cell this inhibitory signal is lost and the NK cell can then kill its target. In addition, NK cells display antibody-dependent cell-mediated cytotoxicity. In this, antibody binds to antigen on the surface of the target cell and then NK cells bind to the Fc portion of the bound antibody and kill the target cell.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 28
Incorrect
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What is the mechanism of action of captopril:
Your Answer: Inhibition of the conversion of angiotensinogen to angiotensin
Correct Answer: Inhibition of the conversion of angiotensin I to angiotensin II
Explanation:Angiotensin-converting enzyme inhibitors (ACE inhibitors) e.g. captopril inhibit the conversion of angiotensin I to angiotensin II, and thus have a vasodilatory effect, lowering both arterial and venous resistance. The cardiac output increases and, because the renovascular resistance falls, there is an increase in renal blood flow. This latter effect, together with reduced aldosterone release, increases Na+ and H2O excretion, contracting the blood volume and reducing venous return to the heart.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 29
Incorrect
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You investigated a patient with a chest infection and want to start antibiotics right away. The patient says they she can't take cephalosporins when you ask about allergies.Choose the 'second-generation' cephalosporin from the following choices?Â
Your Answer: Ceftriaxone
Correct Answer: Cefuroxime
Explanation:Cephalosporins of the first generation include cephalexin, cefradine, and cefadroxil. Urinary tract infections, respiratory tract infections, otitis media, and skin and soft-tissue infections are all treated with them.Second-generation cephalosporins include cefuroxime, cefaclor, and cefoxitin. These cephalosporins are less vulnerable to beta-lactamase inactivation than the ‘first-generation’ cephalosporins. As a result, they’re effective against germs that are resistant to other antibiotics, and they’re especially effective against Haemophilus influenzae.Cephalosporins of the third generation include cefotaxime, ceftazidime, and ceftriaxone. They are more effective against Gram-negative bacteria than second generation’ cephalosporins. They are, however, less effective against Gram-positive bacteria such Staphylococcus aureus than second-generation cephalosporins.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 30
Correct
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A 24 year old male sustained an insect bite and presents with a red hot arm and acute cellulitis has been diagnosed. The predominant white cells in this type of acute inflammation are:
Your Answer: Neutrophils
Explanation:Neutrophil polymorphs are the predominant type of white cells in an acute reaction. They pass between endothelial cell junctions to invade damaged tissue so that the effects of injury can be combated. Extravasation occurs with the movement of leukocytes out of the vessel lumen, and is achieved in five phases which are margination, ‘rolling’, adhesion, transmigration and chemotaxis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 31
Incorrect
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Tiredness, night sweats, and easy bruising are symptoms of a 58-year-old woman. Splenomegaly is observed during the examination.Which of the following diagnoses is the SINGLE MOST LIKELY?
Your Answer: Non-Hodgkin lymphoma
Correct Answer: Chronic myeloid leukaemia (CML)
Explanation:CML is a myeloproliferative disorder characterised by an abnormal pluripotent haemopoietic stem cell. A cytogenetic abnormality known as the Philadelphia chromosome, which results from a reciprocal translocation between the long arms of chromosomes 9 and 22, causes more than 80% of cases of CML.CML is a disease that develops slowly over several years. This is known as the ‘chronic stage.’ This stage is usually asymptomatic, and 90 percent of patients are diagnosed at this point, with the disease being discovered frequently as a result of a routine blood test. During this stage, the bone marrow contains less than 10% immature white cells (blasts).When CML cells expand, symptoms typically begin to appear. The ‘accelerated stage’ is what it’s called. Approximately 10% of people are diagnosed at this point. During this stage, between 10% and 30% of blood cells in the bone marrow are blasts. During this stage, common clinical features include:Fatigue and exhaustionNight sweats and feverDistension of the abdomenPain in the left upper quadrant (splenic infarction)Splenomegaly (commonest examination finding)HepatomegalyBruising is simple.Gout is a type of arthritis that affects (rapid cell turnover)Hyperviscosity is a condition in which the viscosity of (CVA, priapism)A small percentage of patients experience a ‘blast crisis’ (blast stage). More than 30% of the blood cells in the bone marrow are immature blast cells at this stage. Patients with severe constitutional symptoms (fever, weight loss, bone pain), infections, and bleeding diathesis typically present at this stage.In CML, laboratory findings include:White cell count is abnormally high (often greater than 100 x 109/l).Increased number of immature leukocytes causes a left shift.Anaemia that is mild to moderately normochromic and normocytic.Platelets can be low, normal, or elevated, and the Philadelphia chromosome can be found in > 80% of patients. Serum uric acid and ALP levels are frequently elevated. Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, are the current mainstay of CML treatment. Allogenic bone marrow transplantation is now only used in cases where TKIs have failed to work.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 32
Incorrect
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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 forms part of the hypothenar eminence
Correct 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.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 33
Correct
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Regarding Gaussian sample distribution, which of the following statements is false?
Your Answer: It can be skewed left or right
Explanation:Gaussian distribution, also known as normal distribution, is the most important probability distribution in statistics because it fits many natural phenomena. The normal distribution is a probability function that describes how the values of a variable are distributed. Below are its characteristics:(1) Bell-shaped and symmetrical about the mean(2) The mean, median, mode are all equal(3) The total area under the curve and above the x-axis is equal to 1(4) It has long tapering tails extending infinitely but never touching the x-axis(5) It is determined by its parameters: its mean and standard deviation(6) The standard deviation becomes a more meaningful quality than merely being a measure of dispersionThe mean is the most common measure of central tendency. It is the sum of all observed values divided by the number of observation, and is also known as the ‘average’.The median is the value that falls in the middle position when the observations are ranked in order from the smallest to the largest. If the number of observations is odd, the median is the middle number. If it is even, the median is the average of the two middle numbers.The mode is the value that occurs with the greatest frequency in a set of observations, and is commonly used in public health statistics, such as the top 10 causes of mortality.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 34
Correct
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A 35 year old man presents with a deep laceration to the proximal part of the forearm. On further assessment, the patient is unable to flex the metacarpophalangeal joints and interphalangeal joints of the index, middle finger and the thumb. The ring and little fingers are intact but there is weakness at the proximal interphalangeal joint.There is also loss of sensation over the lateral palm and the palmar surface of the lateral three and a half fingers. Which of these nerve(s) has most likely been affected?
Your Answer: Median nerve
Explanation:A median nerve injury affecting the extrinsic and intrinsic muscles of the hand will present with:Loss of sensation to the lateral palm and the lateral three and a half fingers.Weakness of flexion at the metacarpophalangeal joints of the index and middle finger. This is because of paralysis of the lateral two lumbricals. Weakness of flexion of the proximal interphalangeal joints of all four fingers due to paralysis of the flexor digitorum superficialisWeakness of flexion at the distal interphalangeal joints of the index and middle finger following paralysis of the lateral half of the flexor digitorum profundus.Weakness of thumb flexion, abduction and opposition due to paralysis of the flexor pollicis longus and thenar muscles
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 35
Correct
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A 23-year-old male is referred to your haematology clinic after an acute attack of haemolytic anaemia. He was diagnosed with glucose-6-phosphate dehydrogenase deficiency ten years ago. Which ONE of the following options is FALSE with regards to this disorder?
Your Answer: Acute haemolysis can be triggered by cephalosporin antibiotics
Explanation:Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive disorder in which there is a deficiency of the enzyme G6PD. This causes instability of red blood cell membranes under oxidative stress leading to haemolysis.Triggers include: 1) Fava beans2) Sulphonamides3) Primaquine4) Anti-TB drugs5) Infections Most individuals will be asymptomatic until exposed to one of the triggers listed above. It is the commonest human enzyme defect and affects males more than females because of the X-linked inheritance pattern. The use of penicillins and cephalosporins is generally safe.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 36
Correct
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A 78-year-old woman visits the emergency room with dizziness and nausea. She claims that her doctor gave her cinnarizine two days prior, but that it didn't seem to help.Cinnarizine's mechanism of action is which of the following?
Your Answer: Antihistamine action
Explanation:Cinnarizine is a piperazine derivative with an antihistamine effect that makes it anti-emetic. Motion sickness and vestibular disorders, such as Méniéres disease, are the most common conditions for which it is prescribed.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 37
Correct
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Which of the following is NOT a contraindication to the use of diazepam:
Your Answer: Acute alcohol withdrawal
Explanation:Benzodiazepines are used to treat symptoms in patients with acute alcohol withdrawal syndrome. Benzodiazepines are contraindicated in: Respiratory depressionMarked neuromuscular respiratory weakness, such as unstable myasthenia gravisObstructive sleep apnoea syndrome (symptoms may be aggravated)Severe hepatic impairment (the elimination half-life of diazepam may be prolonged; increased risk of coma)Phobic or obsessional states, chronic psychosis or hyperkinesis (paradoxical reactions may occur).
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 38
Incorrect
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Regarding antihistamines, which of the following statements is CORRECT:
Your Answer: Antihistamines act on H2 receptors.
Correct Answer: Elderly patients and children are more susceptible to side effects.
Explanation:Elderly patients and children are more susceptible to side effects. Antihistamines are competitive inhibitors at the H1-receptor. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent. Antihistamines are used as a second line adjunct to adrenaline in anaphylaxis.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 39
Correct
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Which ONE statement about homeostasis is true?
Your Answer: Negative feedback occurs via receptors, comparators and effectors
Explanation:Homeostasis is the property of a system in which variables are regulated so that internal conditions remain relatively constant and stable. Homeostasis is achieved by a negative feedback mechanism.Negative feedback occurs based upon a set point through receptors, comparators and effectors. The ‘set point’ is a NARROW range of values within which normal function occurs.The two body systems that regulate homeostasis are the Nervous system and the Endocrine system. The smooth muscle of the uterus becomes more active towards the end of pregnancy. This is a POSITIVE feedback.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 40
Correct
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All of the muscles of the tongue (other than the palatoglossus) are innervated by which of the following nerves:
Your Answer: Hypoglossal nerve
Explanation:All of the muscles of the tongue are innervated by the hypoglossal nerve, except for the palatoglossus, which is innervated by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 41
Correct
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Which of the following is the most potent stimulus of fibrinolysis:
Your Answer: Tissue plasminogen activator
Explanation:Fibrinolysis is a normal haemostatic response to vascular injury. Plasminogen, a proenzyme in blood and tissue fluid, is converted to plasmin by activators either from the vessel wall (intrinsic activation) or from the tissues (extrinsic activation). The most important route follows the release of tissue plasminogen activator (TPA) from endothelial cells.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 42
Correct
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A 52-year-old patient requires procedural sedation for DC cardioversion of atrial fibrillation. You plan on using propofol as the sedative agent.Propofol works as a result of action on what type of receptor? Select ONE answer only.
Your Answer: Gamma-aminobutyric acid (GABA)
Explanation:Propofol (2,6-diisopropylphenol) is a short-acting phenol derivative that is primarily used for the induction of anaesthesia.Its mechanism of action is unclear but is thought to act by potentiating the inhibitory neurotransmitters GABA and glycine, which enhances spinal inhibition during anaesthesia.The dose for induction of anaesthesia is 1.5-2.5mg/kg. The dose for maintenance of anaesthesia is 4-12 mg/kg/hour. Following intravenous injection, propofol acts within 30 seconds and its duration of action is 5-10 minutes.Propofol produces a 15-25% decrease in blood pressure and systemic vascular resistance without a compensatory increase in heart rate. It is negatively inotropic and decreases cardiac output by approximately 20%.The main side effects of propofol are:Pain on injection (in up to 30%)HypotensionTransient apnoeaHyperventilationCoughing and hiccoughHeadacheThrombosis and phlebitis
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 43
Incorrect
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Regarding T helper cells, which of the following statements is CORRECT:
Your Answer: They secrete cytokines which directly neutralise bacterial toxins.
Correct Answer: They form the vast majority (about 75%) of the total circulating T-cell population.
Explanation:CD4+ T-cells (Helper T cells)Recognise antigen only in association with HLA class II molecules (found on antigen presenting cells (APCs) e.g. dendritic cells, B-cells; present exogenous antigens that have been phagocytosed/endocytosed into intracellular vesicles)Form most of the circulating T-cell population (about 75%)Secrete cytokines (e.g. IFN-gamma) which are required for recruitment and activation of other immune cells such as macrophages, T cytotoxic cells and NK cells and for the activation of and production of immunoglobulin from B-cells
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 44
Correct
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Which of the following statements about propofol is TRUE:
Your Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 45
Correct
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A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.Which of these anatomic structures is the most superficial structure injured in the case above?
Your Answer: Camper’s fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:SkinFatty layer of the superficial fascia (Camper’s fascia)Membranous layer of the superficial fascia (Scarpa’s fascia)Aponeurosis of the external and internal oblique musclesRectus abdominis muscleAponeurosis of the internal oblique and transversus abdominisFascia transversalisExtraperitoneal fatParietal peritoneum
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 46
Incorrect
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A 55-year-old woman with history of gastritis and reflux esophagitis tested positive for Helicobacter pylori infection. Which of the following statements regarding Helicobacter pylori is considered true?
Your Answer: It is an obligate anaerobe
Correct Answer: It is helix shaped
Explanation:Helicobacter pylori is a curved or helix-shaped, non-spore forming, Gram-negative, microaerophilic bacteria. It is motile, having multiple flagella at one pole. It has a lipopolysaccharide component in its outer membrane.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 47
Incorrect
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One of your patients is in resuscitation and is suffering from kidney failure. The intensive care outreach team arrives to assess them and determines that a dopamine infusion is necessary.Dopamine primarily acts on which of the following receptors at low doses?
Your Answer: Alpha-1 receptors
Correct Answer: Dopamine receptors
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.Below is a summary of the mechanisms and effects of various inotropic agents:InotropeMechanismEffectsAdrenaline (epinephrine)Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesNoradrenaline (norepinephrine)Mainly alpha-agonist;Beta-1 and -2 agonist at increasing dosesVasoconstriction;Some increased cardiac outputDopamineDopamine agonist at low doses;Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesDobutamineMainly beta-1 agonistIncreased cardiac output
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 48
Incorrect
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Compliance is decreased by all but which one of the following:
Your Answer: Pulmonary fibrosis
Correct Answer: Aging
Explanation:Factors increasing compliance:Old ageEmphysemaFactors decreasing compliance:Pulmonary fibrosisPulmonary oedemaAtelectasisExtremes of lung volumes (at higher lung volumes the compliance of the lung becomes less as the lung becomes stiffer)
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 49
Correct
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A 22-year-old with a history of brittle asthma is brought to the ED by her partner. She is wheezing and very short of breath and her condition is deteriorating rapidly. Following a series of nebulisations, hydrocortisone and IV magnesium sulphate, she is taken to resus and the intensive care team is called to review her. She is severely hypoxic and confused and a decision is made to intubate her.Which of these drugs is ideal as an induction agent in this patient?
Your Answer: Ketamine
Explanation:Only about 2% of asthma attacks requires intubation and most severe cases are managed with non-invasive ventilation techniques.Though life-saving in the crashing asthmatic, intubation in asthmatic patients is associated with significant morbidity and mortality and is risky. Indications for intubation in asthmatic patients include:Severe hypoxiaAltered mental stateRespiratory or cardiac arrestFailure to respond to medicationsKetamine (1-2 mg/kg) is the preferred induction agent. It has bronchodilatory properties and does not cause hypotension. Propofol poses a risk of hypotension but can also be used.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 50
Incorrect
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Which of the following hormones regulates Na+reabsorption in the proximal tubule:
Your Answer: Renin
Correct Answer: Angiotensin II
Explanation:Angiotensin II increases Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters).
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This question is part of the following fields:
- Physiology
- Renal
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Question 51
Incorrect
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Which of the following statements is false regarding the biceps brachii muscle?
Your Answer: It is innervated by the musculocutaneous nerve
Correct Answer: It pronates the radioulnar joint in the forearm
Explanation:The biceps brachii muscle is one of the chief muscles of the arm. The origin at the scapula and the insertion into the radius of the biceps brachii means it can act on both the shoulder joint and the elbow joint, which is why this muscle participates in a few movements of the arm. It derives its name from its two heads which merge in one unique distal body, defining the unusual structure of the muscle.The biceps brachii muscle is supplied by the musculocutaneous nerve (C5-C6), a branch of the brachial plexus.Arterial supply to the biceps brachii muscle varies considerably, coming from up to eight vessels originating from the brachial artery in the middle third of the arm.In the shoulder joint both muscle heads partially enforce opposite movements. The long head pulls the arm away from the trunk (abduction) and turns it inwards (inward rotation) whereas the short head pulls the arm back towards the trunk (adduction). When both heads contract simultaneously it leads to an arm bend (flexion). In the elbow joint the muscle bends the forearm (flexion) and rotates it outwards (supination). The supination is most powerful in a flexed elbow. In addition to the movement functions, the biceps has the important task to support the humeral head within the shoulder joint. Its antagonist is the triceps brachii in the posterior compartment of the arm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 52
Correct
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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: 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.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 53
Correct
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Question 54
Correct
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A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 55
Correct
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Hepatitis A is transmitted by which of the following routes:
Your Answer: Faecal-oral route
Explanation:Hepatitis A transmission is by the faecal-oral route; the virus is excreted in bile and shed in the faeces of infected people.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 56
Incorrect
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A 43 year old lady who has a previous medical history of hyperthyroidism presents to the emergency room with sweating, palpitations and agitation. On examination, she is tachycardic, hypertensive and hyperpyrexic. She recently had a stomach bug and has not been able to take her medication regularly. The best medication to immediately treat her symptoms is which of the following?
Your Answer: Hydrocortisone
Correct Answer: Propranolol
Explanation:There is a high suspicion of a thyroid crisis in this patient and emergent treatment should be initiated even before the results of TFT’s have returned. Antiadrenergic drugs like IV propranolol should be administered immediately to minimise sympathomimetic symptoms. Antithyroid medications like propylthiouracil or carbimazole should be administered to block further synthesis of thyroid hormones. After thionamide therapy has been started to prevent stimulation of new hormone synthesis, there should then be delayed administration of oral iodine solution. Hydrocortisone administration is also recommended as it treats possible relative adrenal insufficiency while also decreases peripheral conversion of T4 to T3.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 57
Correct
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A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.Which of the following muscles is most likely to be involved? Select ONE answer only.
Your Answer: Sternothyroid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:Muscles: thyrohyoid, sternothyroid, sternohyoid musclesOrgans: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid glandArteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteriesVeins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veinsNerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.Contents:Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodesNerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 58
Correct
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A 59-year-old woman presents with a history of tiredness and weight gain and a diagnosis of hypothyroidism is suspected.Which of these changes is likely to appear first in primary hypothyroidism?
Your Answer: Increased thyroid-stimulating hormone (TSH)
Explanation:The earliest biochemical change seen in hypothyroidism is an increase in thyroid-stimulating hormone (TSH) levels.Triiodothyronine (T3) and thyroxine (T4) levels are normal in the early stages.TBG levels are generally unchanged in primary hypothyroidism.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 59
Correct
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Which of the following causes increased aldosterone secretion:
Your Answer: Decreased blood volume
Explanation:Decreased blood volume stimulates the secretion of renin (because of decreased renal perfusion pressure) and initiates the renin-angiotensin-aldosterone cascade. Angiotensin-converting enzyme (ACE) inhibitors block the cascade by decreasing the production of angiotensin. Hyperosmolarity stimulates antidiuretic hormone (ADH) [not aldosterone] secretion. Hyperkalaemia, not hypokalaemia, directly stimulates aldosterone secretion by the adrenal cortex. ANPÂ inhibits renin secretion, thereby inhibiting the production of angiotensin and aldosterone.
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This question is part of the following fields:
- Physiology
- Renal
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Question 60
Correct
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Which of the following nerves supply the superficial head of the flexor pollicis brevis muscle?
Your Answer: The recurrent branch of the median nerve
Explanation:The two heads of the flexor pollicis brevis usually differ in their innervation. The superficial head of flexor pollicis muscle receives nervous supply from the recurrent branch of the median nerve, whereas the deep head receives innervation from the deep branch of the ulnar nerve, derived from spinal roots C8 and T1.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 61
Incorrect
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Which nerve supplies the muscle flexor hallucis longus?
Your Answer: Superficial peroneal nerve
Correct Answer: Tibial nerve
Explanation:Flexor hallucis longus is innervated by the tibial nerve, composed of spinal roots L4, L5, S1, S2, and S3.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 62
Incorrect
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A patient allergic to penicillin and with marked cellulitis presents and you decide to start him on erythromycin.Which statement about macrolide antibiotics is true?
Your Answer: They act by binding to the 30S subunit of the bacterial ribosome
Correct Answer: They are actively concentrated within leukocytes
Explanation:Macrolide antibiotics are bacteriostatic. They act by binding to the 50S subunit of the bacterial ribosome inhibit protein synthesis. Macrolide antibiotics are actively concentrated within leukocytes, because of this, they are transported into the site of infection.Macrolide antibiotics are not effective in meningitis as they do not penetrate the central nervous system well. They are mainly against Gram-positive organisms and can be used as an alternative in patients with penicillin allergy.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 63
Incorrect
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A patient presents with a necrolytic migratory rash. Her blood serum glucagon concentration is 1246 pg/mL. Following further investigations, she is diagnosed with glucagonoma.Which SINGLE statement regarding glucagon is true?
Your Answer: Its secretion is inhibited by adrenaline
Correct Answer: It makes fatty acids available for oxidation
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.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 64
Incorrect
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You've been asked to give a discussion to a group of medical students about skeletal muscle physiology and its use in clinical medicine. They pose a series of difficult questions to you.Which of the following definitions for the A-band of the sarcomere is correct?
Your Answer: Zones of thin filaments extending from either side of the Z-lines to the start of the thick filament (myosin)
Correct Answer: A band that contains the entire length of a single thick filament (myosin)
Explanation:Myofibrils, which are around 1 m in diameter, make up each myofiber. The cytoplasm separates them and arranges them in a parallel pattern along the cell’s long axis. These myofibrils are made up of actin and myosin filaments that are repeated in sarcomeres, which are the myofiber’s basic functional units.Myofilaments are the filaments that make up myofibrils, and they’re made mostly of proteins. Myofilaments are divided into three categories:Myosin filaments are thick filaments made up mostly of the protein myosin.Actin filaments are thin filaments made up mostly of the protein actin.Elastic filaments are mostly made up of the protein titin.The sarcomere is a Z-line segment that connects two adjacent Z-lines.The I-bands are thin filament zones that run from either side of the Z-lines to the thick filament’s beginning.Between the I-bands is the A-band, which spans the length of a single thick filament.The H-zone is a zone of thick filaments that is not overlaid by thin filaments in the sarcomere’s centre. The H-zone keeps the myosin filaments in place by surrounding them with six actin filaments each.The M-band (or M-line) is a disc of cross-connecting cytoskeleton elements in the centre of the H-zone.The thick filament is primarily made up of myosin. The thin filament is primarily made up of actin. Actin, tropomyosin, and troponin are found in a 7:1:1 ratio in thin filaments.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 65
Correct
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A 20-year-old male has an anaphylactic reaction following a wasp sting.What type of hypersensitivity reaction is this?
Your Answer: Type I
Explanation:Anaphylaxis is an example of a type I hypersensitivity reaction. It is IgE mediated. It requires a prior exposure to the antigen. The initial exposure sensitizes the body to the antigen and a second exposure to that antigen leads to an anaphylactic reaction.Massive calcium influx into the cells leads to mast cell degranulation. The Immunoglobulin antigen complex binds to Fc receptors on the surface of mast cells. The result is mast cell degranulation and release of histamine, proteoglycans and serum proteases from cytoplasmic granules.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 66
Correct
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A 6-year-old girl is brought to the nephrology clinic by her mother due to facial oedema. Her lab workup shows proteinuria of 7 g/24 hours and serum albumin levels of 15 g/L. A diagnosis of Nephrotic Syndrome is made, and corticosteroid therapy is initiated. Which one of the following is the most likely cause of nephrotic syndrome in this patient?
Your Answer: Minimal change disease
Explanation:Minimal Change Disease is the most common cause of Nephrotic Syndrome in the paediatric population. It may be caused by NSAID use. Electron microscopy shows the fusion of foot processes while light microscopy will appear normal.Focal segmental glomerulosclerosis causes Nephrotic Syndrome in adults. It is associated with Heroin use and HIV infection. There is a limited response to steroids, and the disease progresses to end-stage renal failure in 5-10 years.Diabetic nephropathy occurs after a long period of diabetes due to the deposition of amyloid protein leading to a decrease in glomerular filtration. There is no history of Hepatitis B in this patient and no symptoms of liver disease such as jaundice. Membranous glomerulonephritis would present with features of Nephritic Syndrome. These would be oedema, haematuria; red blood cell casts in the urine and hypertension.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 67
Incorrect
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Regarding Clostridium difficile, which of the following statements is CORRECT:
Your Answer: It has endotoxin-mediated effects causing profuse watery diarrhoea.
Correct Answer: It is normally found in gut flora.
Explanation:C. difficile is normally found in the gut flora but its growth is normally suppressed by more dominant anaerobes. It has exotoxin-mediated effects causing profuse diarrhoea. Oral clindamycin (a broad spectrum antibiotic) is commonly implicated in precipitating C. difficile colitis; first line treatment is with oral metronidazole. Tetanolysin is a toxin produced by Clostridium tetani bacteria.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 68
Correct
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A 38-year-old woman is investigated for Addison's disease. She had low blood pressure, weakness, weight loss, and skin discoloration. An adrenocorticotropic hormone (ACTH) stimulation test is scheduled as part of her treatment.Which of the following statements about ACTH is correct?Â
Your Answer: It is released in response to the release of CRH
Explanation:The anterior pituitary gland produces and secretes a peptide hormone called adrenocorticotropic hormone (ACTH) (adenohypophysis). It is secreted in response to the hypothalamus’s secretion of the hormone corticotropin-releasing hormone (CRH).ACTH promotes cortisol secretion via binding to cell surface ACTH receptors in the zona fasciculata of the adrenal cortex.ACTH also promotes the production of beta-endorphin, which is a precursor to melanocyte-releasing hormone (MRH).
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 69
Correct
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A 40-year-old woman was rushed to the Emergency Department due to an anaphylactic reaction after being stung by a bee. She responded well to initial treatment but developed anaphylactic symptoms after 6 hours. Her symptoms were resolved after a further dose of adrenaline. Her family threatened legal action as they thought she had not received adequate treatment but withdrew their accusation after the attending physician explained that the woman had suffered a biphasic reaction. What is the approximate percentage of people who suffer this type of reaction?
Your Answer: 20%
Explanation:Anaphylactic reactions are Type 1 hypersensitivity reactions IgE-mediated and can be potentially life-threatening if not treated promptly. There are four well-recognized patterns of anaphylaxis:1) Uniphasic2) Biphasic3) Protracted4) RefractoryBiphasic reactions occur in 20% of the population, although their mechanism is poorly understood. The symptoms of anaphylaxis recur within 4-6 hours, although they may also recur up to 72 hours later. All patients discharged from the hospital after an anaphylactic shock must:1) Be warned to return to the hospital immediately if symptoms recur2) Have a treatment plan in place3) Have a follow-up appointment4) Be considered for an adrenaline auto-injector5) Referred to an allergy clinic
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 70
Incorrect
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Which of the following is a contraindication to using nitrous oxide:
Your Answer: Third degree heart block
Correct Answer: Raised intracranial pressure
Explanation:Nitrous oxide should not be utilized in patients with an air-containing confined area because it diffuses into these spaces, causing a rise in pressure. This includes circumstances like pneumothorax, intracranial air after a head injury, imprisoned air from a recent undersea dive, a recent intraocular gas injection, or intestinal blockage. Nitrous oxide increases cerebral blood flow and should be avoided in individuals who have or are at risk of having high intracranial pressure.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 71
Correct
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Which of the following is a contraindication to the use of opioid analgesics:
Your Answer: Raised intracranial pressure
Explanation:Opioids should be avoided in people who have: A risk of paralytic ileus (opioids reduce gastric motility)Acute respiratory depressionAn acute exacerbation of asthma (opioids can aggravate bronchoconstriction as a result of histamine release)Conditions associated with increased intracranial pressure including head injury (opioids can interfere with pupillary response making neurological assessment difficult and may cause retention of carbon dioxide aggravating the increased intracranial pressure)
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 72
Incorrect
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A man working as a waiter cuts his arm on a glass while he was working. The palmaris longus muscle was damaged as a consequence of his injury.Which of the following statements regarding the palmaris longus muscle is considered correct?
Your Answer: It is innervated by the radial nerve
Correct Answer: It receives its blood supply from the ulnar artery
Explanation:The palmaris longus is a small, fusiform-shaped muscle located on the anterior forearm of the human upper extremity. The palmaris longus muscle is commonly present but may be absent in a small percentage of the population, ranging from 2.5% to 26% of individuals, depending on the studied population.The palmaris longus belongs to the anterior forearm flexor group in the human upper extremity. The muscle attaches proximally to the medial humeral epicondyle and distally to the palmar aponeurosis and flexor retinaculum. The blood supply to the palmaris longus muscle is via the ulnar artery, a branch of the brachial artery in the human upper extremity.The palmaris longus muscle receives its innervation via branches of the median nerve containing nerve roots C5-T1. Median nerve injury at or above the elbow joint (including brachial plexus and nerve root injury) can lead to deficits in the palmaris longus and other forearm flexor muscles, leading to weakened elbow flexion, wrist flexion, radial deviation, finger flexion, thumb opposition, flexion, and abduction, in addition to the loss of sensory function in the distribution of the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 73
Incorrect
-
What is the pathophysiology of a phaeochromocytoma:
Your Answer: Aldosterone-secreting tumour
Correct Answer: Catecholamine-secreting tumour
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 74
Incorrect
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Regarding bile acids, which of the following statements is INCORRECT:
Your Answer: Of the bile acids excreted into the intestine, about 95% are reabsorbed.
Correct Answer: The main primary bile acids are deoxycholic acid and lithocholic acid.
Explanation:Bile acids have a hydrophobic and a hydrophilic end and in aqueous solution, bile salts orient themselves around droplets of lipid forming micelles to keep the lipid droplets dispersed. The principal primary bile acids are cholic acid and chenodeoxycholic acid. They are made more soluble by conjugation with taurine or glycine in the liver. Of the bile acids excreted into the intestine, about 95% are reabsorbed into the portal circulation by active transport mechanisms in the distal ileum and recycled by the liver.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 75
Incorrect
-
Antinuclear antibodies (ANAs) also referred to as anti-nuclear factors (ANFs) are autoantibodies that bind to contents of the cell nucleus.Which ONE of these statements about ANAs is true?
Your Answer: Anti-Ro antibodies are associated with CREST syndrome
Correct Answer: They can be of any immunoglobulin class
Explanation:Anti-nuclear antibodies(ANAs) also referred to as anti-nuclear factors (ANFs) are autoantibodies that bind to contents of the cell nucleus. They can be of any immunoglobulin class.CREST syndrome is usually associated with anti-centromere antibodies.ELISA testing is cheaper but not the most accurate means of testing for ANAs. Indirect immunofluorescence testing is the most reliable.Nucleolar staining is suggestive of scleroderma, while homogenous staining is suggestive of lupus.Anti-dsDNA antibodies are found in 80 – 90% of patients with SLE
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 76
Correct
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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.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 77
Incorrect
-
A man presents to the emergency department with an injury that has damaged the opponens pollicis muscle.Which of the following statements regarding the opponens pollicis muscle is considered correct?
Your Answer: It assists with the abduction of the thumb
Correct Answer: It flexes the first metacarpal bone at the carpometacarpal joint
Explanation:Opponens pollicis is a muscle of thenar eminence, it is triangular in shape and lies deep to flexor pollicis brevis and abductor pollicis brevis. It originates from the flexor retinaculum, tubercles of scaphoid and trapezium, abductor pollicis longus tendon.Its insertion is in the radial side of the base of proximal phalanx of thumb. It is supplied by the median nerve (C8, T1). It receives blood supply from superficial arch.It flexes the metacarpal bone medially across the palm, also rotating it medially, causing opposition, the palmar aspect of the terminal segment of thumb contacts the flexor aspects of any other digit.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 78
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.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 79
Correct
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Question 80
Correct
-
A thyroid function test is done for a 55-year-old woman with non-specific symptoms, the results are shown below:TSH = 5.2Free T4 is normalFree T3 is normalThe most likely diagnosis in this patient is?
Your Answer: Subclinical hypothyroidism
Explanation:Hypothyroidism is diagnosed using the results of thyroid function tests (TFTs). In the early stages of the disease, the earliest biochemical change noticed is a rise in thyroid-stimulating hormone (TSH) levels. Free triiodothyronine (T3) and thyroxine (T4) levels are usually normal.In primary hypothyroidism, the serum TSH level is usually greater than 10 mU/L, and free T4 levels are below the reference range.Subclinical hypothyroidism is diagnosed when the serum TSH level is above the reference range, and the free T4 levels are within the reference range. The test should, however, be repeated after 3-6 months to exclude transient causes of raised TSH.In summary, how to interpret TFTs in cases of suspected hypothyroidism is shown below:Subclinical hypothyroidismTSH is raisedFree T4 is normalFree T3 is normalPrimary hypothyroidismTSH is raisedFree T4 is loweredFree T3 is lowered or normalSecondary hypothyroidismTSH is lowered or normalFree T4 is loweredFree T3 is lowered or normal
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 81
Incorrect
-
Regarding inflammatory bowel disease, acute mild to moderate disease of the rectum or rectosigmoid should be treated initially with:
Your Answer: Oral steroid
Correct Answer: Local aminosalicylate
Explanation:Acute mild to moderate disease affecting the rectum (proctitis) or the rectosigmoid is treated initially with local application of an aminosalicylate; alternatively, a local corticosteroid can be used but it is less effective. A combination of a local aminosalicylate and a local corticosteroid can be used for proctitis that does not respond to a local aminosalicylate alone.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 82
Incorrect
-
A 28-year-old patient who has been in a car accident needs to be intubated using a rapid sequence induction. As an induction agent, you intend to use etomidate.Etomidate works by interacting with which type of receptor?
Your Answer: Dopamine
Correct Answer: Gamma-aminobutyric acid (GABA)
Explanation:Etomidate is a carboxylated imidazole derivative with a short half-life that is primarily used to induce anaesthesia.It is thought to modulate fast inhibitory synaptic transmission in the central nervous system by acting on GABA type A receptors.The dose for anaesthesia induction is 0.3 mg/kg. Etomidate takes 10-65 seconds to take effect after an intravenous injection, and it lasts 6-8 minutes. With repeated administration, the effects are non-cumulative.The relative cardiovascular stability of etomidate is noteworthy. During induction, it causes less hypotension than thiopental sodium and propofol. It’s also linked to a quick recovery without the hangover.Etomidate is a strong steroidogenesis inhibitor. The drug inhibits the enzymes responsible for adrenal 11 beta-hydroxylase and cholesterol cleavage, resulting in a decrease in cortisol and aldosterone synthesis for up to 24 hours after administration. It should not be used to maintain anaesthesia because of the adrenocortical suppression.Other side effects associated with etomidate use include:Vomiting and nauseaThe injection causes pain (in up to 50 percent )Phlebitis and thrombosis of the veinsHeart block and arrhythmiasHyperventilationApnoea and respiratory depressionIt has the potential to cause both hypo- and hypertension.Critically ill patients have a higher mortality rate.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 83
Incorrect
-
Which of the following is NOT an adverse effect associated with statin therapy:
Your Answer: Interstitial lung disease
Correct Answer: Aplastic anaemia
Explanation:Adverse effects of statins include:, Headache, Epistaxis, Gastrointestinal disorders (such as constipation, flatulence, dyspepsia, nausea, and diarrhoea), Musculoskeletal and connective tissue disorders (such as myalgia, arthralgia, pain in the extremity, muscle spasms, joint swelling, and back pain), Hyperglycaemia and diabetes, Myopathy and rhabdomyolysis, Interstitial lung disease and Hepatotoxicity
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 84
Incorrect
-
A 36-year-old woman is 22-weeks pregnant and is investigated for a possible thyroid disorder. When her total thyroid hormone levels does not correlate with her thyrometabolic status, her thyroid-binding globulin levels are checked.What percentage of circulating thyroid hormones is bound to thyroid-binding globulin?
Your Answer: 40%
Correct Answer: 70%
Explanation:Only a very small fraction of the thyroid hormones circulating in the blood are free. The majority is bound to transport proteins. Only the free thyroid hormones are biologically active, and measurement of total thyroid hormone levels can be misleading. The relative percentages of bound and unbound thyroid hormones are:Bound to thyroid-binding globulin -70%Bound to albumin -15-20%Bound to transthyretin -10-15%Free T3 -0.3%Free T4 -0.03%
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 85
Correct
-
A young male has presented to the Emergency Department with a sudden onset of severe palpitations, shortness of breath, and chest pain. A 12-lead ECG is recorded, and it shows a narrow complex tachycardia that points to a diagnosis of supraventricular tachycardia. Vagal manoeuvres are attempted but are unsuccessful in eliminating the arrhythmia. The next action plan is to use a drug to revert to sinus rhythm. Out of the following, which is the first-line treatment for supraventricular tachycardia?
Your Answer: Adenosine
Explanation:Paroxysmal supraventricular tachycardia is an intermittent tachycardia (HR > 100 bpm) and has the following characteristics:1. Sudden onset/offset (Contrast with sinus tachycardia)2. Electrical activity originates above the ventricle (Contrast with ventricular tachycardia)3. Produces narrow QRS complex (<120ms) The most common cause of PSVT is Atrioventricular nodal re-entrant tachycardia (AVNRT), most common in young women with a mean age onset of 32 years old. There are recurrent episodes of palpitations, and most of the episodes spontaneously. Sometimes, some vagal manoeuvres are required:1. Valsalva manoeuvre2. immersing the face in ice-cold water3. carotid sinus massage.If PSVT keeps persisting or is causing severe symptoms, the treatment of choice is intravenous adenosine. The patient’s ECG should be continuously monitored throughout the treatment. The recommended doses in adults are as follows:- Initial dose of adenosine is 6 mg by rapid IV bolus- If unsuccessful, give another dose of adenosine 12 mg by rapid IV bolus- If unsuccessful, give a further dose of adenosine 12 mg by rapid IV bolusThe latest ALS guidelines advocate 18 mg for the third dose, whereas the BNF/NICE guidelines advocate 12 mg.If adenosine fails or is contraindicated, intravenous verapamil can be used as an alternative, but it should be avoided in patients recently treated with beta-blockers.Synchronized electrical cardioversion will be necessary with signs of hemodynamic instability or if drug treatment has failed to restore sinus rhythm.Recurrent episodes of paroxysmal supraventricular tachycardia can be treated by catheter ablation or prevented with drugs such as flecainide, sotalol, diltiazem, or verapamil.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 86
Correct
-
Which of the following nerves provides sensory innervation to the anteromedial and anterosuperior aspects of the external ear?
Your Answer: Auriculotemporal nerve
Explanation:Sensory innervation to the external ear is supplied by both cranial and spinal nerves. Branches of the trigeminal, facial, and vagus nerves (CN V, VII, X) are the cranial nerve components, while the lesser occipital (C2, C3) and greater auricular (C2, C3) nerves are the spinal nerve components involved. The lateral surface of the tympanic membrane, the external auditory canal, and the external acoustic meatus are all innervated by nervus intermedius (a branch of CN VII), the auriculotemporal nerve (CN V3), and the auricular branch of the vagus nerve. The concha receives split innervation from nervus intermedius, the auricular branch of the vagus nerve, and the greater auricular (spinal) nerve. Beyond the concha, the anteromedial and anterosuperior parts of the pinna are innervated by the auriculotemporal nerve, and a portion of the lateral helix by the lesser occipital nerve. The greater auricular nerve provides innervation to the area of the pinna inferolateral to the lobule.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 87
Incorrect
-
A 24-year-old man goes to the emergency department with a fever, headache, and swollen parotid glands that are excruciating. You have a suspicion that it is mumps. Which of the following nerves is causing the discomfort the patient is experiencing:
Your Answer: Buccal nerve
Correct Answer: Auriculotemporal nerve
Explanation:The auriculotemporal nerve is irritated by mumps, which results in significant discomfort due to inflammation and swelling of the parotid gland, as well as the stretching of its capsule. Compression caused by swallowing or chewing exacerbates pain.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 88
Correct
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Which of the following statements is considered correct regarding Klebsiella infections?
Your Answer: Klebsiella spp. are non-motile
Explanation:Klebsiella is a Gram-negative, rod-shaped, non-motile bacteria. The absence of motility distinguishes Klebsiella spp. from most other members of the family Enterobacteriaceae. K. pneumoniae is the most commonly isolated species and has the distinct feature of possessing a large polysaccharide capsule. The capsule offers the organism protection against phagocytosis and antimicrobial absorption,contributing to its virulence. Colonization of gram-negative bacilli in the respiratory tracts of hospitalized patients, particularly by K. pneumoniae, increases with the length of hospital stay. It is a frequent cause of lower respiratory tract infections among hospitalized patients and in immunocompromised hosts such as newborns,elderly patients, and seriously ill patients on respirators.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 89
Correct
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A 20-year-old male patient lives in a travelling community and has never received any vaccinations. He presents to you with fever.Which of these statements concerning indications and contraindications for vaccination is FALSE?
Your Answer: Premature infants should have the their immunisation schedule adjusted for gestational age
Explanation:All vaccines are contraindicated in individuals with:A confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.A confirmed anaphylactic reaction to a component in the vaccine e.g. neomycinLive attenuated vaccines are contraindicated in pregnancy except in cases where risk of infection is more than the risks of vaccination.During times of acute febrile illness, vaccination should be avoided.12 weeks should elapse after a dose of human immunoglobulin before a live vaccine is administered.The normal times recommended for immunization of full-term babies should also be applied to premature infants and correction for gestational age should NOT be implemented.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 90
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.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 91
Incorrect
-
Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: Air flow is driven by, and is directly proportional to, the mouth-alveolar pressure gradient
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.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 92
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)
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 93
Incorrect
-
Which of the following is characterised by passive carrier-mediated transport down a chemical concentration gradient:
Your Answer: Diffusion
Correct Answer: Facilitated diffusion
Explanation:Facilitated diffusion is the process of spontaneous passive transport of molecules or ions down their concentration gradient across a cell membrane via specific transmembrane transporter (carrier) proteins. The energy required for conformational changes in the transporter protein is provided by the concentration gradient rather than by metabolic activity.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 94
Correct
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You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).What is the MAIN contributory factor in this condition's immunodeficiency?
Your Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 95
Correct
-
In the Kaplan-Meier plot, which of the following labels should be applied to the X-axis?
Your Answer: Time in years
Explanation:Kaplan-Meier estimate is one of the best options to be used to measure the fraction of subjects living for a certain amount of time after treatment. In clinical trials or community trials, the effect of an intervention is assessed by measuring the number of subjects survived or saved after that intervention over a period of time. The time starting from a defined point to the occurrence of a given event, for example death, is called as survival time and the analysis of group data as survival analysis. The graph plotted between estimated survival probabilities/estimated survival percentages (on Y axis) and time past after entry into the study (on X axis) consists of horizontal and vertical lines.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 96
Incorrect
-
A 7-year-old boy is brought to the emergency room with complaints of a red and painful left eye. Upon physical examination, it was noted that there is the presence of conjunctival erythema. A mucopurulent discharge and crusting of the lid was also evident. A diagnosis of bacterial conjunctivitis was made. According to the latest NICE guidelines, which of the following should NOT be a part of the management of this patient?
Your Answer: Advise that no school exclusion is necessary
Correct Answer: Topical antibiotics should be prescribed routinely
Explanation:The following are the NICE guidelines on the management of bacterial conjunctivitis:- Infective conjunctivitis is a self-limiting illness that usually settles without treatment within 1-2 weeks. If symptoms persist for longer than two weeks they should return for review.- Seek medical attention urgently if marked eye pain or photophobia, loss of visual acuity, or marked redness of the eye develop.- Remove contact lenses, if worn, until all symptoms and signs of infection have completely resolved and any treatment has been completed for 24 hours.- Lubricant eye drops may reduce eye discomfort; these are available over the counter, as well as on prescription.- Clean away infected secretions from eyelids and lashes with cotton wool soaked in water.- Wash hands regularly, particularly after touching the eyes.- Avoid sharing pillows and towels.- It is not necessary to exclude a child from school or childcare if they have infective conjunctivitis, as mild infectious illnesses should not interrupt school attendance. An exception would be if there is an outbreak of infective conjunctivitis, when advice should be sought from the Health Protection Agency by the school. – Adults who work in close contact with others, or with vulnerable patients, should avoid such contact until the discharge has settled.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 97
Incorrect
-
What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer: Dopamine receptor agonist
Correct Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 98
Incorrect
-
A 38-year-old taxi driver sustained blunt force trauma to his anterior chest from the steering wheel of his car after falling asleep while driving headlong into an oncoming HGV lorry. Bruising around his sternum was observed, which appears to be the central point of impact. Which of the following structures is most likely injured by the blunt force trauma?
Your Answer: Left atrium
Correct Answer: Right ventricle
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:Anterior (or sternocostal) – Right ventriclePosterior (or base) – Left atriumInferior (or diaphragmatic) – Left and right ventriclesRight pulmonary – Right atriumLeft pulmonary – Left ventricle
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 99
Correct
-
A patient has a diagnosis of acute osteomyelitis. They have no joint prosthesis on indwelling metal work and no known drug allergies. He has had a recent skin swab that has cultured MRSA and MRSA infection is suspected.Which of the following antibacterial agents would be most appropriate to prescribe in this case? Select ONE answer only.
Your Answer: Vancomycin
Explanation:In the majority of patients the commonest causative organism for osteomyelitis isStaphylococcus aureus.Salmonella spp. are the commonest cause in patients with sickle cell disease.Other bacteria that can cause osteomyelitis include:Enterobacter spp.Group A and B streptococcusHaemophilus influenzaeThe current recommendations by NICE and the BNF on the treatment of osteomyelitis are:Flucloxacillin first-lineConsider adding fusidic acid or rifampicin for initial 2 weeksIf penicillin allergic use clindamycinIf MRSA is suspected use vancomycinSuggested duration of treatment is 6 weeks for acute infection
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 100
Incorrect
-
Which of the following best characterizes the correct administration of amiodarone for a shockable rhythm in adults on advanced life support:
Your Answer: Give 300 mg IV amiodarone after the first shock
Correct Answer: Give 300 mg IV amiodarone after 3 shocks
Explanation:After three shocks, 300 mg IV amiodarone should be administered. After five defibrillation attempts, a further dose of 150 mg IV amiodarone may be considered. If amiodarone is not available, lidocaine may be used as a substitute, but it should not be given if amiodarone has previously been administered.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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