-
Question 1
Incorrect
-
A 35-year-old female, presents to the emergency department via ambulance. The paramedics have noted the patient's symptoms as unilateral left-sided weakness of the upper and lower limbs, homonymous hemianopia and dysphasia. She has previous personal and family history of deep vein thromboses. The report of her CT scan suggests a stroke involving the middle cerebral artery. Post recovery, she undergoes further diagnostic investigations to determine the cause of a stroke at her young age. She is eventually diagnosed with a hypercoagulable state disease called Factor V Leiden thrombophilia. An emboli in the middle cerebral artery results in dysfunction of which areas of the brain?
Your Answer: Frontal, temporal, parietal and occipital lobes
Correct Answer: Frontal, temporal and parietal lobes
Explanation:The middle cerebral artery is a part of the circle of Willis system of anastomosis within the brain, and the most often affected by brain pathology. The primary function of the middle cerebral artery is providing oxygenated blood to related regions of the brain. It achieves this by giving off different branches to supply different brain regions, namely: The cortical branches: which supplies the primary motor and somatosensory cortical areas of some parts of the face, trunk and upper limbs. The small central branches: which supply the basal ganglia and internal capsule via the lenticulostriate vessels. The superior division: which supplies the lateral inferior frontal lobe, including the Broca area which is responsible for production of speech, language comprehension, and writing. The inferior division: which supplies the superior temporal gyrus, including Wernicke’s area which controls speech comprehension and language development.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 2
Incorrect
-
Periodic fevers occur in humans with mutations in the gene for pyrin. Pyrin is a protein found in which one of the following cells?
Your Answer: B lymphocytes
Correct Answer: Neutrophils
Explanation:Pyrin, also known as marenostrin or TRIM20, is a protein encoded by the Mediterranean fever (MEFV) gene, causing the autoinflammatory disease familial Mediterranean fever (FMF). Pyrin produces an increased sensitivity to intracellular signals. It is produced mainly in neutrophils, which display an increased ratio of cells entering apoptosis when exposed to pyrin.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 3
Incorrect
-
Select one true statement about haemoglobin synthesis…
Your Answer: Involves the combination of iron in the ferric (fe3+) state with protoporphyrin to form haem.
Correct Answer: Occurs in the cytosol of developing red cells.
Explanation:Haemoglobin (Hb) is synthesized in a complex series of steps. The haem part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in the cytosol. Production of Hb continues in the cell throughout its early development from the proerythroblast to the reticulocyte in the bone marrow.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 4
Incorrect
-
Which of the toxin secretion pathways in the cell membrane of gram– bacteria delivers the toxin extracellular in a 2 stage process to the host?
Your Answer: VI
Correct Answer: II
Explanation:Gram negative bacteria contain two membranes and there are about six specialized secretion systems. The secreted proteins play a key role in pathogenesis. Type II secretion systems (T2SS) are conserved in most Gram-negative bacteria, where they transport proteins from the periplasm into the extracellular environment. Because the T2SS channel is only found in the outer membrane, proteins secreted through this apparatus must first be delivered to the periplasm via the Sec or Tat secretion pathways and then to the extracellular environment making it a two-stage process.
-
This question is part of the following fields:
- Infectious Diseases
- Physiology
-
-
Question 5
Incorrect
-
Question 6
Correct
-
Low levels of which of the following arterial blood gas parameters stimulate the peripheral chemoreceptors?
Your Answer: Arterial pO 2
Explanation:Chemoreceptors are activated when the chemical composition of their immediate surroundings changes. Peripheral chemoreceptors, together with central chemoreceptors, regulate respiratory functions. They detect changes in arterial blood oxygen levels. Decreased arterial Po2 (partial pressure of oxygen) reflexly stimulates peripheral chemoreceptors. When peripheral chemoreceptors detect changes in arterial blood oxygen, they will trigger cardiorespiratory changes such as an increase in breathing and blood pressure. These reflexes are important for maintaining homeostasis during hypoxemia.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 7
Incorrect
-
The pterygoid plexus receives tributaries from which of the following veins?
Your Answer: Superficial temporal vein
Correct Answer: Maxillary vein
Explanation:The pterygoid plexus of veins is the main venous component associated with the infratemporal fossa. It receives tributaries corresponding to the branches of the internal maxillary artery. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen of Vesalius, foramen ovale and foramen lacerum. The (internal) maxillary vein is a short trunk which accompanies the first part of the (internal) maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus and passes backward between the sphenomandibular ligament and the neck of the mandible and unites with the temporal vein to form the posterior facial vein. It carries blood away from the infratemporal fossa.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 8
Incorrect
-
Which vitamin is found in NAD and NADP?
Your Answer: Vitamin B6
Correct Answer: Vitamin B3
Explanation:In organisms, NAD can be synthesized from simple building-blocks (de novo) from the amino acids tryptophan or aspartic acid. In an alternative fashion, more complex components of the coenzymes are taken up from food as the vitamin called niacin (vitamin B3)
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 9
Incorrect
-
In which of the following would you NOT typically see a neutropaenia:
Your Answer: Aplastic anaemia
Correct Answer: Asplenism
Explanation:Causes of neutropaenia: Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs) Benign (racial or familial) Cyclical Immune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis) Leukaemia Infections (e.g. HIV, hepatitis, fulminant bacterial infection) General Pancytopaenia Hypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia
-
This question is part of the following fields:
- Immunology
- Pathology
-
-
Question 10
Correct
-
The haemostatic plug formation in response to injured blood vessel wall is stimulated by exposure of which substance to platelets?
Your Answer: Collagen
Explanation:When the endothelium is damaged, the normally isolated, underlying collagen is exposed to circulating platelets, which bind directly to collagen with collagen-specific glycoprotein Ia/IIa surface receptors. This adhesion is strengthened further by von Willebrand factor (vWF), which is released from the endothelium and from platelets.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 11
Incorrect
-
Near the transcription site of a gene, the site at which RNA polymerase and its cofactors bind is known as the:
Your Answer: Inhibitor
Correct Answer: Promotor
Explanation:Transcription will begin when the RNA polymerase II binds to the promotor. The promotor is a sequence of 25 nucleotides found upstream from the start site of transcription. This promotor sequence is known as the TATA box. Transcription factors also bond along with RNA polymerase to this site to form a complex. However some may bind to regulatory elements proximal to the promotor site.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 12
Incorrect
-
The glossopharyngeal nerve provides the parasympathetic innervation of the:
Your Answer: Lacrimal gland
Correct Answer: Parotid salivary gland
Explanation:The glossopharyngeal nerve provides parasympathetic innervation for the parotid salivary gland via the auriculotemporal nerve. The facial nerve supplies the parasympathetic innervation of the lacrimal, nasal, sublingual and submandibular glands.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 13
Incorrect
-
The telomerase is capable of adding several more repeats of telomeres at which end of the guanosine rich region.
Your Answer: 5th end
Correct Answer: 3rd end
Explanation:Telomerase is a reverse transcriptase that uses the RNA template to synthesize DNA in the 5th-3rd direction resulting in extension of the 3rd end and then translocates it to the newly synthesized end. The GT rich strand is thus elongated.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 14
Correct
-
Where is the mental foramen located?
Your Answer: In the mandible
Explanation:The mental foramen is found bilaterally on the anterior surface of the mandible adjacent to the second premolar tooth. The mental nerve and terminal branches of the inferior alveolar nerve and mental artery leave the mandibular canal through it.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 15
Incorrect
-
When inserting a chest drain anteriorly into the second intercostal space, one must identify the second costal cartilage by palpating which landmark?
Your Answer: Sternoclavicular joint
Correct Answer: Sternal angle
Explanation:The sternal angle is the site for identification of the second rib as the second rib is attached to the sternum at this point.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 16
Incorrect
-
Regarding the trachea, which of the following statements is INCORRECT:
Your Answer: A cricothyroidotomy is suitable for airway obstruction superior to the vocal folds.
Correct Answer: A cricothyrotomy involves making an opening in the neck inferior to the cricoid cartilage.
Explanation:A cricothyrotomy involves making an opening in the median cricothyroid ligament (the medial part of the cricothyroid membrane), between the cricoid cartilage below and the thyroid cartilage above.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 17
Correct
-
Question 18
Incorrect
-
The coronary sinus drains into the:
Your Answer: Superior vena cava
Correct Answer: Right atrium
Explanation:The coronary sinus drains into the right atrium. Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 19
Correct
-
The process whereby bacterial products interact with plasma factors and cells to produce agents that attract neutrophils to an infected area is called:
Your Answer: Chemotaxis
Explanation:During an inflammatory process many cytokines are produced that act as chemokines to attract neutrophils to the site of inflammation. These include bacterial products, IL-8, C5a and LTB4.
-
This question is part of the following fields:
- Immunology
- Physiology
-
-
Question 20
Incorrect
-
Which enzyme is responsible for the conversion of testosterone to dihydrotestosterone?
Your Answer: 17α-hydroxylase
Correct Answer: 5α-reductase
Explanation:The enzyme 5α-reductase synthesizes DHT from testosterone in the prostate, testes, hair follicles, and adrenal glands. This enzyme reduces the 4,5 double-bond of the testosterone. Relative to testosterone, DHT is much more potent as an agonist of the androgen receptor.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 21
Correct
-
After exercise, O2 debt repay may take up to:
Your Answer: 90 min
Explanation:Physical activity or exercise requires oxygen for production of ATP or energy via aerobic pathways of energy production. When the amount of oxygen that reaches muscles depletes, cells start producing energy anaerobically by partial breakdown of glucose resulting in lactic acid. Lactic acid should be removed from cells as it causes muscle fatigue. Oxygen is needed to oxidize lactic acid in to carbon dioxide and water and this need is known as oxygen debt. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise. This may take up from 60 – 90 mins.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 22
Incorrect
-
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.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 23
Incorrect
-
Which of the atrial pressure changes represents the a-wave of the JVP
Your Answer: Inspiration
Correct Answer: Atrial systole
Explanation:The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 24
Incorrect
-
A 78-year-old woman was brought to the emergency department with decreased consciousness, weakness and dehydration. Which serum electrolyte would most likely be low in this patient?
Your Answer: K+
Correct Answer: Na+
Explanation:Hyponatremia is a sodium level below 135 mEq/L. Signs and symptoms may include: nausea with vomiting, fatigue, headache or confusion, cramps or spasm, irritability and restlessness and severe cases may lead to seizures and comma.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 25
Correct
-
Which of the following forms the language areas of the cerebral cortex?
Your Answer: All of the above
Explanation:Broca’s area, Wernicke’s area, the submarginal sulcus and the angular gyrus all form the language areas of the cerebral cortex.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 26
Incorrect
-
Arterioles stemming from the coronary artery can also empty into the heart directly via the:
Your Answer: AV fistulas
Correct Answer: Arteriosinusoidal vessels
Explanation:Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers. They include arteriosinusoidal vessels, which connect the arterioles to the heart chambers. The thebesian veins drain the capillaries into the chambers and the arterioluminal vessels drain small arteries directly into the chambers.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 27
Incorrect
-
Cellular Theory of Ageing
Your Answer: Loss of telomeres
Correct Answer: Gene regulation
Explanation:Cellular theories of aging propose that human aging is the result of cellular aging, whereby an increasing proportion of cells reach senescence, a terminal stage at which cells will cease to divide. This will limit the body’s ability to regenerate and to respond to injury or stress.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 28
Correct
-
Which one of the following is a risk factor for torsade de pointes?
Your Answer: Hypothermia
Explanation:The following is a list of factors associated with an increased tendency toward torsades de pointes:- Hypokalaemia (low blood potassium)- Hypomagnesemia (low blood magnesium)- Hypocalcaemia (low blood calcium)- Bradycardia (slow heartbeat)- Heart failure- Left ventricular hypertrophy- Hypothermia- Subarachnoid haemorrhage- Hypothyroidism
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 29
Correct
-
Which of the following nerves is responsible for the symptoms of a patient who presented with ophthalmic herpes zoster and a few vesicles on the nose?
Your Answer: Trigeminal nerve
Explanation:Hutchinson sign relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve which is a branch of the ophthalmic division of the trigeminal nerve. The nasociliary branch of the trigeminal nerve innervates the apex and lateral aspect of the nose, as well as the cornea. Therefore, lesions on the side or tip of the nose should raise suspicion of ocular involvement.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 30
Incorrect
-
Somatostatin is responsible for?
Your Answer: Increased pancreatic secretions
Correct Answer: Decreased gastrin release
Explanation:Somatostatin is an inhibitory hormone secreted from the D cells of the Pancreatic Islets. It causes the inhibition of gastrin (decreasing stomach acid production), CCK (decreasing gallbladder motility), gastrin inhibitory peptide and secretin. Gastrin production is also inhibited by secretin, GIP, VIP, glucagon and calcitonin.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
