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Question 1
Incorrect
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A 27-year-old man presents with a laceration of his forearm that severed the nerve that innervates flexor carpi radialis.
Which of the following nerves has been damaged in this case? Select ONE answer only.Your Answer: The musculocutaneous nerve
Correct Answer: The median nerve
Explanation:Flexor carpi radialis is innervated by the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 2
Incorrect
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Depolarisation of a neuron begins with which of the following:
Your Answer: Opening of voltage-gated K + channels
Correct Answer: Opening of ligand-gated Na + channels
Explanation:Action potentials are initiated in nerves by activation of ligand-gated Na+channels by neurotransmitters. Opening of these Na+channels results in a small influx of sodium and depolarisation of the negative resting membrane potential (-70 mV). If the stimulus is sufficiently strong, the resting membrane depolarises enough to reach threshold potential (generally around -55 mV), at which point an action potential can occur. Voltage-gated Na+channels open, causing further depolarisation and activating more voltage-gated Na+channels and there is a sudden and massive sodium influx, driving the cell membrane potential to about +40 mV.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 3
Incorrect
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Regarding an avulsion fracture, a sudden contraction of which muscle may lead to fracture of the head of the fibula?
Your Answer: Peroneus brevis
Correct Answer: Biceps femoris
Explanation:Avulsion fractures of the fibular head are rare and are so-called the arcuate signal. The “arcuate signal” is used to describe an avulsed bone fragment related to the insertion site of the tendon of the biceps femoris associated with the arcuate complex, which consists of the fabellofibular, popliteofibular, and arcuate ligaments. Such lesions are typically observed in direct trauma to the knee with excessive varus and internal rotation forces or indirect trauma with the same direction of the force.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 4
Incorrect
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The common bile duct drains into the duodenum in which of the following regions:
Your Answer: First part of the duodenum
Correct Answer: Second part of the duodenum
Explanation:As the common bile duct descends, it passes posterior to the first part of the duodenum before joining with the pancreatic duct from the pancreas, forming the hepatopancreatic ampulla (ampulla of Vater) at the major duodenal papilla, located in the second part of the duodenum. Surrounding the ampulla is the sphincter of Oddi, a collection of smooth muscle which can open to allow bile and pancreatic fluid to empty into the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 5
Incorrect
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A patient suffered from a chest injury while working out in the gym. As a consequence of his injury, his pectoralis minor muscle was damaged.
Which of the following statements regarding the pectoralis minor muscle is considered correct?Your Answer: It is thicker than pectoralis major
Correct Answer: It stabilises the scapula
Explanation:The pectoralis minor, in comparison to the pectoralis major, is much thinner and triangular in shape and resides below the major. It originates from the margins of the third to fifth ribs adjacent to the costochondral junction. The fibres consequently pass upward and laterally to insert into the medial border and superior surface of the coracoid process. It is crucial in the stabilization of the scapula by pulling it downward and anteriorly against the thoracic wall.
Arterial supply to the pectoralis minor also derives from the pectoral branch of the thoracoacromial trunk. Nerve supply of the pectoralis minor is a function of the lateral pectoral nerve and the medial pectoral nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 6
Correct
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Regarding Escherichia coli, which of the following statements is INCORRECT:
Your Answer: It is a predominant member of the normal flora of the skin.
Explanation:Escherichia coli is a Gram-negative bacilli that is an important member of the intestinal flora. It is the most common cause of UTI in adults (about 70 – 95% of cases), followed by Staphylococcus saprophyticus (about 5 – 10% of cases), and an important cause of neonatal meningitis. E. coli O157 strain is implicated in the development of dysentery associated with haemolytic uraemic syndrome characterised by haemolytic anaemia, thrombocytopenia and acute renal failure.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 7
Correct
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What kind of function loss do you anticipate in a 22-year-old guy who had a laceration to his arm, resulting in nerve damage in the antecubital fossa?
Your Answer: Opposition of thumb
Explanation:The symptoms of median nerve injury include tingling or numbness in the forearm, thumb, and three adjacent fingers, as well as gripping weakness and the inability to move the thumb across the palm.
Because the thenar muscles and the flexor pollicis longus are paralyzed, flexion, abduction, and opposition of the thumb at the MCPJ and IPJ are gone.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 8
Correct
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In patients requiring oxygen, who are at risk of hypercapnic respiratory failure, oxygen saturations should be maintained at:
Your Answer: 88 - 92%
Explanation:A lower target of 88 – 92% oxygen saturation is indicated for patients at risk of hypercapnic respiratory failure e.g. patients with COPD. Until blood gases can be measured, initial oxygen should be given using a controlled concentration of 28% or less, titrated towards the SpO2 of 88 – 92%. The aim is to provide the patient with enough oxygen to achieve an acceptable arterial oxygen tension without worsening carbon dioxide retention and respiratory acidosis.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 9
Incorrect
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Regarding antacids, which of the following statements is CORRECT:
Your Answer: Antacids increase absorption of digoxin.
Correct Answer: Antacids are contraindicated in hypophosphataemia.
Explanation:Antacids are contraindicated in hypophosphataemia. Liquid preparations are more effective than tablet preparations. Magnesium-containing antacids tend to be laxative whereas aluminium-containing antacids tend to be constipating. Antacids are best taken when symptoms occur or are expected, usually between meals and at bedtime. Antacids should preferably not be taken at the same time as other drugs since they may impair absorption.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 10
Correct
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Which of the following is the correct sequential order of the phases of healing:
Your Answer: Haemostasis, inflammation, proliferation, remodelling
Explanation:Acute wound healing has four main stages: haemostasis, inflammation, proliferation and remodelling.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 11
Incorrect
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Adenosine is primarily indicated for which of the following:
Your Answer: Bradyarrhythmias
Correct Answer: Paroxysmal supraventricular tachycardia
Explanation:Adenosine is usually the treatment of choice for terminating paroxysmal supraventricular tachycardia including those associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 12
Incorrect
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Blood flows from the left atrium into the left ventricle via:
Your Answer: The tricuspid valve
Correct Answer: The mitral valve
Explanation:Blood flows from the right atrium into the right ventricle via the tricuspid atrioventricular valve and from the left atrium into the left ventricle via the mitral atrioventricular valve. Blood is ejected from the right ventricle through the pulmonary semilunar valve into the pulmonary artery and from the left ventricle via the aortic semilunar valve into the aorta.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 13
Incorrect
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A 42-year-old male patient, presenting with polyuria and polydipsia symptoms had normal blood test results. Upon interview, he had mentioned being in a car accident in which he had a head injury. His polyuria and polydipsia symptoms are most likely associated with which of the following conditions?
Your Answer: Type 2 diabetes mellitus
Correct Answer: Cranial diabetes insipidus
Explanation:Polydipsia is the feeling of extreme thirstiness. It is often linked to polyuria, which is a urinary condition that causes a person to urinate excessively. The cycle of these two processes makes the body feel a constant need to replace the fluids lost in urination. In healthy adults, a 3 liter urinary output per day is considered normal. A person with polyuria can urinate up to 15 liters of urine per day. Both of these conditions are classic signs of diabetes.
The other options are also types of diabetes, except for psychogenic polydipsia (PPD), which is the excessive volitional water intake seen in patients with severe mental illness or developmental disability. However, given the patient’s previous head injury, the most likely diagnosis is cranial diabetes insipidus.
By definition, cranial diabetes insipidus is caused by damage to the hypothalamus or pituitary gland after an infection, operation, brain tumor, or head injury. And the patient’s history confirms this diagnosis. To define the other choices, nephrogenic diabetes insipidus happens when the structures in the kidneys are damaged and results in an inability to properly respond to antidiuretic hormone.
Kidney damage can be caused by an inherited (genetic) disorder or a chronic kidney disorder. As with cranial diabetes insipidus, nephrogenic diabetes insipidus can also cause an elevated urine output.
Diabetes mellitus is classified into two types, and the main difference between them is that type 1 diabetes is a genetic disorder, and type 2 diabetes is diet-related and develops over time. Type 1 diabetes is also known as insulin-dependent diabetes, in which the pancreas produces little or no insulin. Type 2 diabetes is termed insulin resistance, as cells don’t respond customarily to insulin.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 14
Correct
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Regarding antihistamines, which of the following statements is CORRECT:
Your Answer: Elderly patients and children are more susceptible to side effects.
Explanation:Elderly patients and children are more susceptible to side effects. Antihistamines are competitive inhibitors at the H1-receptor. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent. Antihistamines are used as a second line adjunct to adrenaline in anaphylaxis.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 15
Incorrect
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Which of the following muscles laterally rotates the hip?
Your Answer: Semimembranosus
Correct Answer: Gluteus maximus
Explanation:External (lateral) rotation at the hip joint is produced by the gluteus maximus together with a group of 6 small muscles (lateral rotators): piriformis, obturator internus, superior and inferior gemelli, quadratus femoris and obturator externus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 16
Incorrect
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A 30-year-old male with a known allergy to natural latex rubber presents with an allergic reaction to a food he has just eaten.
Which ONE of these foods is most likely to cause an associated hypersensitivity in him?Your Answer: Orange
Correct Answer: Banana
Explanation:About one third of patients with allergy to natural latex rubber (NRL) have an associated allergy to some plant-derived foods. It is known as the latex-fruit syndrome and occurs commonly with consumption of fresh fruits. Banana and avocado are the most implicated fruits but it can also be seen with tomato, kiwi and chestnut.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 17
Incorrect
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Leukaemia has been diagnosed in a 6-year-old child on your list. He comes to the ER with a complication related to this diagnosis.
Which type of leukaemia do you think this is?Your Answer: Chronic myeloid leukaemia
Correct Answer: Acute lymphoblastic leukaemia
Explanation:Acute lymphoblastic leukaemia (ALL) is the most common childhood cancer that primarily affects children. ALL is most common between the ages of 2 and 4, and it is uncommon in adults.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 18
Incorrect
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A 27-year-old female is brought to the Emergency Department by ambulance with extensive bleeding from her upper arm following a fall from a bicycle onto a fence. On inspection her biceps brachii muscle has been lacerated.
How will the muscle heal from this injury? Select ONE answer only.Your Answer: Scar formation with no myocyte regeneration
Correct Answer: Satellite cells will produce a small number of regenerated myocytes
Explanation:Muscle heals with fibrous tissue to form a scar. Once cut, it will never regain its previous bulk or power. Within the scar a small number of myocytes (muscle cells) may be seen, which are formed from satellite cells but they contribute little to the function of the muscle overall.
In more widespread ischaemic injury, such as critical ischaemic limb due to arterial compromise, or in compartment syndrome, damaged myocytes are replaced diffusely with fibrous tissue. This fibrous tissue contracts and reduces movement, and in extreme cases can pull the limb into abnormal positions such as in Volkmann’s ischaemic contracture of the forearm. -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 19
Incorrect
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You come across a 60-year-old woman with a history of chronic pancreatitis. Today she is complaining of epigastric pain. She has blood tests done especially to review her cholecystokinin levels.
Which of the following is a cholecystokinin (CCK) releasing site?Your Answer: D-cells in the pancreas
Correct Answer: I-cells in the upper small intestine
Explanation:The I-cells in the duodenum generate and release cholecystokinin (CCK), a peptide hormone. It has a crucial role in the digestion process as a hormonal regulator.
CCK cells are concentrated in the proximal small intestine, and when food is consumed, the hormone is produced into the bloodstream. The presence of partly digested lipids and proteins in the duodenum is one of the most powerful stimulus for CCK synthesis.
CCK’s key physiological effects include:
Encourages the pancreas to release digesting enzymes into the small intestine.
Stimulates gallbladder contraction and sphincter of Oddi relaxation, resulting in bile delivery into the duodenum.
Gastric emptying is inhibited, and gastric acid output is reduced.
Satiety induction is a process that involves inducing a feeling of fullness. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 20
Incorrect
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A 66-year-old male is brought to your clinic by his wife with the complaint of increasing confusion and disorientation over the past three days, along with decreased urination. She reports that he has been complaining of increasing pain in his back and ribs over the past three months.
On examination, the patient looks anaemic, is not oriented in time, place and person and has tenderness on palpation of the lumbar spine and the 10th, 11th and 12th ribs.
Blood tests show anaemia which is normocytic, normochromic, raised urea and creatinine and hypercalcemia.
Which one of the following diagnoses is most likely in this case?Your Answer: Vitamin B12 deficiency
Correct Answer: Multiple myeloma
Explanation:Multiple myeloma is a clonal abnormality affecting plasma cells in which there is an overproduction of functionless immunoglobulins. The most common patient complaint is bone pain, especially in the back and ribs. Anaemia and renal failure are common, along with hypercalcemia. Hypercalcemia may lead to an altered mental status, as in this case.
Chronic lymphocytic leukaemia occurs due to the overproduction of lymphocytes, usually B cells. CLL may present with an asymptomatic elevation of B cells. Patients are generally more than 50 years old and present with non-specific fatigue and weight loss symptoms.
There is no history of alcohol abuse in this case. Furthermore, patients with a history of alcohol abuse may have signs of liver failure, which are not present here.
Metastatic prostate cancer would most often cause lower backache as it metastasises first to the lumbar spine via the vertebral venous plexus.
A patient with Vitamin B12 deficiency would have anaemia, megaloblastic, hypersegmented neutrophils, and signs of peripheral neuropathy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 21
Incorrect
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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: Basophils
Correct 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 22
Correct
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A 33 year old lady with a known nut allergy was having dinner at a Thai restaurant. She suddenly complained of lip and tongue swelling and difficulty breathing and is brought to ED by ambulance with suspected anaphylaxis. She received intramuscular adrenaline in the ambulance.
The most appropriate doses of the second line treatments for anaphylaxis are which of the following?Your Answer: 10 mg chlorphenamine and 200 mg hydrocortisone
Explanation:Second line drugs to reduce the severity and duration of anaphylactic symptoms are intravenous or intramuscular chlorpheniramine and hydrocortisone. The recommended dose is 10 mg chlorpheniramine and 200 mg hydrocortisone in adults.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 23
Incorrect
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A patient presents with an acute severe asthma attack. Following a poor response to his initial salbutamol nebuliser, you administer a further nebuliser that this time also contains ipratropium bromide.
After what time period would you expect the maximum effect of the ipratropium bromide to occur? Select ONE answer only.Your Answer: 1-2 hours
Correct Answer: 30 -60 minutes
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.
The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.
The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.
The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma) -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 24
Correct
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You examine a 34-year-old lady with symptoms that are consistent with acute sinusitis. You're thinking about giving her doxycycline for treatment.
What is doxycycline's mechanism of action?Your Answer: Inhibition of protein synthesis
Explanation:Doxycycline and other tetracycline antibiotics attach to the 30S subunit of the bacterial ribosome, preventing aminoacyl-tRNA binding and so protein synthesis beginning.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 25
Incorrect
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Which JVP waveform correlates to atrial systole?
Your Answer: The y descent
Correct Answer: The a wave
Explanation:JVP Waveform in Cardiac Cycle Physiology: a wave Right atrial contraction causes atrial systole (end diastole). the c wave During right isovolumetric ventricular contraction, the tricuspid valve bulges into the right atrium, resulting in isovolumetric contraction (early systole). descent by x Rapid ventricular ejection (mid systole) is caused by a combination of right atrial relaxation, tricuspid valve downward movement during right ventricular contraction, and blood ejection from both ventricles. the v-wave Ventricular ejection and isovolumetric relaxation (late systole) occur as a result of venous return filling the right atrium. y lineage Ventricular filling occurs when the tricuspid valve opens, allowing blood to flow rapidly from the right atrium to the right ventricle.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 26
Incorrect
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A patient suffers a lower limb fracture that causes damage to the nerve that innervates peroneus brevis.
Peroneus brevis receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Femoral nerve
Correct Answer: Superficial peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.
Peroneus longus is innervated by the superficial peroneal nerve.
Peroneus tertius is innervated by the deep peroneal nerve. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 27
Incorrect
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Which of the following classes of drugs may predispose to lithium toxicity:
Your Answer: Theophylline
Correct Answer: Thiazide diuretics
Explanation:Excretion of lithium may be reduced by thiazide diuretics, NSAIDs, and ACE inhibitors thus predisposing to lithium toxicity. Loop diuretics also cause lithium retention but are less likely to result in lithium toxicity.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 28
Incorrect
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer: ITP is the most common cause of isolated thrombocytopaenia without anaemia or neutropaenia.
Correct Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 29
Incorrect
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Regarding transport across a membrane, which of the following statements is CORRECT:
Your Answer: Facilitated diffusion is an active process requiring metabolic energy.
Correct Answer: Ion channels may be voltage-gated or ligand-gated.
Explanation:Diffusion is the passive movement of ions across a cell membrane down their electrochemical or concentration gradient through ion channels. Ion channels can be voltage-gated (regulated according to the potential difference across the cell membrane) or ligand-gated (regulated by the presence of a specific signal molecule). 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. In secondary active transport there is no direct coupling of ATP but the initial Na+ electrochemical gradient that drives the secondary active transport is set up by a process that requires metabolic energy. Examples include the sodium/calcium exchanger, or the sodium/glucose symporter.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 30
Incorrect
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An very unwell patient is receiving treatment in your hospital's HDU and is found to have an Escherichia coli O157 infection.
Which one of these statements about Escherichia coli O157 is true?Your Answer: The incubation period is typically 6-12 hours
Correct Answer: Haemolytic uraemic syndrome develops in approximately 6% of patients
Explanation:Escherichia coli O157 is a serotype of Escherichia coli.
The Escherichia coliO157 strain is ‘enterohaemorrhagic’ and causes severe forms of acute haemorrhagic diarrhoea. It can also cause non-haemorrhagic diarrhoea.Incubation period of Escherichia coli O157 is usually 3-4 days and bloody diarrhoea usually begins on the 3rd or 4th day of the infection.
Infections with Escherichia coliO157 are more common during the warmer months than in winter.
Haemolytic uraemic syndrome develops in approximately 6% of patients. It is commonly seen in children and in the elderly.
Escherichia coli O157 can also cause:
Haemorrhagic colitis
Haemolytic uraemic syndrome
Thrombotic thrombocytopenic purpura but not immune thrombocytopenic purpura. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 31
Incorrect
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What is the main mechanism of action of flecainide:
Your Answer: Closes K+ channels
Correct Answer: Blocks Na+ channels
Explanation:Flecainide inhibits the transmembrane influx of extracellular Na+ ions via fast channels on cardiac tissues resulting in a decrease in rate of depolarisation of the action potential, prolonging the PR and QRS intervals. At high concentrations, it exerts inhibitory effects on slow Ca2+ channels, accompanied by moderate negative inotropic effect.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 32
Incorrect
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Dexamethasone would be most useful for which of the following conditions:
Your Answer: Emergency management of anaphylaxis
Correct Answer: Raised intracranial pressure secondary to malignancy
Explanation:Dexamethasone has a very high glucocorticoid activity in conjunction with insignificant mineralocorticoid activity. This makes it particularly suitable for high-dose therapy in conditions where fluid retention would be a disadvantage such as in the management of raised intracranial pressure or cerebral oedema secondary to malignancy. Dexamethasone also has a long duration of action and this, coupled with its lack of mineralocorticoid action makes it particularly suitable for suppression of corticotropin secretion in congenital adrenal hyperplasia. In most individuals a single dose of dexamethasone at night, is sufficient to inhibit corticotropin secretion for 24 hours. This is the basis of the ‘overnight dexamethasone suppression test’ for diagnosing Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 33
Incorrect
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Which of the following tracts must be affected if a patient presents with decreased pain and temperature sensation in both lower extremities?
Your Answer: The reticulospinal tract
Correct Answer: The lateral spinothalamic tract
Explanation:The main function of the spinothalamic tract is to carry pain and temperature via the lateral part of the pathway and crude touch via the anterior part. The spinothalamic tract pathway is an imperative sensory pathway in human survival because it enables one to move away from noxious stimuli by carrying pain and temperature information from the skin to the thalamus where it is processed and transmitted to the primary sensory cortex. The primary sensory cortex communicates with the primary motor cortex, which lies close to it, to generate rapid movement in response to potentially harmful stimuli. Furthermore, the spinothalamic tract has a role in responding to pruritogens, causing us to itch. Interestingly, itching suppresses the spinothalamic tract neuron response to the histamine effect.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 34
Incorrect
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Which of the following is NOT an advantage of a cohort study used to investigate the relationship between exposure to a risk factor and a future outcome:
Your Answer: Can give a direct estimate of disease incidence rates
Correct Answer: Particularly suitable for rare diseases
Explanation:Advantages: ideal for studying associations between an exposure and an outcome when the exposure is uncommon, the time sequence of events can be assessed, they can provide information on a wide range of disease outcomes, the absolute and relative risk of disease can be measured directly, they can give a direct estimation of disease incidence rates
Disadvantages: costly and can take long periods of time if the outcome is delayed, subject to subject-selection and loss to follow-up bias, large sample size required for rare outcome of interest so it is not useful for rare diseases, prone to confounding -
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 35
Incorrect
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A 30-year-old man suffers from an open fracture of his forearm. As a consequence of his injury, the nerve that innervates the pronator quadratus muscle was severed.
Which of the following statements regarding the pronator quadratus muscle is considered correct?Your Answer: It is innervated by the radial nerve
Correct Answer: Its deep fibres bind the radius and ulna together
Explanation:Pronator quadratus is a deep-seated, short, flat, and quadrilateral muscle with fibres running in a parallel direction.
It arises from the oblique ridge on the anterior surface of the distal fourth of the Ulna. It is inserted in lateral border and anterior surface of the distal fourth of the radius. It is innervated by the anterior interosseous nerve, a branch of the median nerve (C8-T1). It is vascularized by the anterior interosseous artery.
The action of the pronator quadratus muscle along with the pronator teres result in the pronation of the radioulnar joint. Contraction of this muscle pulls the distal end of the radius over the ulna, resulting in the pronation of the radioulnar joint
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 36
Incorrect
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How is filtered K+mainly reabsorbed in the thick ascending limb of the loop of Henle:
Your Answer: Primary active transport via Na + /K + ATPase
Correct Answer: Secondary active transport via Na + /K + /2Cl - cotransporter
Explanation:Around 30% of filtered K+is reabsorbed in the thick ascending limb of the loop of Henle, primarily via the luminal Na+/K+/2Cl-cotransporter, but there is also significant paracellular reabsorption, encouraged by the positive potential in the tubular lumen.
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This question is part of the following fields:
- Physiology
- Renal
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Question 37
Incorrect
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A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
Which of the following is a verapamil toxicity?Your Answer: Increased afterload
Correct Answer: Negative inotropy
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium-channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The following summarises the toxicity of calcium-channel blockers:
Cardiac effects
Vascular smooth muscle tone affects
Metabolic effects
Excessive negative inotropy: myocardial depression
Negative chronotropy: sinus bradycardia
Negative dromotropy: atrioventricular node blockade
Decreased afterload
Systemic hypotension
Coronary vasodilation
Hypoinsulinaemia
Calcium channel blocker-induced insulin resistance -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 38
Incorrect
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When inserting a Seldinger chest drain for management of pneumothorax, the 'safe triangle' should be identified. Which of the following forms the inferior border of the 'safe triangle'?
Your Answer: 3 rd intercostal space
Correct Answer: 5 th intercostal space
Explanation:Care and management of the thoracostomy tubes (chest tubes) are subject to the direction and practice pattern of the responsible physician. Therefore, it is difficult to make a “one size fits all” set of instructions about the specific management recommendations for all chest tubes. It is recommended to discuss specific expectations for management with the patient’s attending physician. Facility specific Clinical Practice Guidelines (CPGs) may provide further guidance for one’s practice.
Placement of the appropriately sized chest tube is performed on the affected side. The typical landmark for placement is the 4th or 5th intercostal space (nipple line for males, inframammary fold for females) at the anterior axillary line. The space above the 5th intercostal space and below the base of the axilla that is bordered posteriorly by the trapezius and anteriorly by the pectoralis muscle has recently been described as the safe triangle. Tubes are positioned anteriorly for pneumothoraces and posteriorly for fluid processes.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 39
Incorrect
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Question 40
Incorrect
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The following structures all lie anteriorly to the oesophagus EXCEPT for the:
Your Answer:
Correct Answer: Thoracic duct
Explanation:Posterior to the oesophagus, the thoracic duct is on the right side inferiorly but crosses to the left more superiorly (at T5).
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This question is part of the following fields:
- Anatomy
- Thorax
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