-
Question 1
Incorrect
-
Which is primarily responsible for the conversion of T4 to T3 in the periphery.
Your Answer: Reverse deiodinase
Correct Answer: Deiodinase 1
Explanation:Type 1 iodothyronine deiodinase, also known simply as deiodinase 1, is an enzyme which can produce both triiodothyronine (active form) or inactivate metabolites from T4. It responsible for almost 80% of the conversion of peripheral T4 to T3. Iodothyronine deiodinases are not to be confused with iodotyrosine deiodinases, which are also part of the deiodinase enzymes.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 2
Incorrect
-
A growing tumour is impinging on the lingual artery in the floor of the mouth. Which structure will experience decreased blood flow?
Your Answer: The skin of the lower lip
Correct Answer: The sublingual gland
Explanation:The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. The gland receives its blood supply from the sublingual and submental arteries. The sublingual artery is a branch of the lingual artery, thus damage to the lingual artery will decrease the blood flow to the sublingual gland.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 3
Correct
-
A 20-year-old woman had profuse watery diarrhoea for 2 days. She felt dizzy and weak, and thus decided to seek medical attention. At the emergency room her BP was 80/60 mmHg with a pulse of 118/min. What is the most appropriate intravenous treatment that should be given?
Your Answer: Isotonic saline
Explanation:Normal saline is typically the first fluid used when hypovolemia is severe enough to threaten the adequacy of blood circulation. It is isotonic and has long been believed to be the safest fluid to give quickly in large volumes.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 4
Incorrect
-
Dicrotic notch is produced by which valves?
Your Answer: Mitral and pulmonary
Correct Answer: Aortic
Explanation:The graph of aortic pressure throughout the cardiac cycle displays a small dip (the incisure or dicrotic notch) which coincides with the aortic valve closure. The dip in the graph is immediately followed by a brief rise (the dicrotic wave) then gradual decline.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 5
Correct
-
Which of the following muscles is least likely to be involved in forceful expiration:
Your Answer: External intercostal muscles
Explanation:Forceful expiration is primarily produced by the deeper thoracic muscles (internal and innermost intercostal muscles, subcostals and transversus thoracis) aided by contraction of the abdominal wall muscles which increase intra-abdominal pressure thus further reducing the volume of the thorax.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 6
Incorrect
-
Which statement is correct about the clinical state of methemoglobinemia?
Your Answer: Methaemoglobin, present in the circulation in small quantities, can resemble cyanosis.
Correct Answer: May arise due to a hereditary deficiency of NADH.
Explanation:Methaemoglobin is a form of haemoglobin that contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. Spontaneously formed methaemoglobin is normally reduced by protective enzyme systems, e.g., NADH methaemoglobin reductase, hence a deficiency of NADH may result in increased levels of methaemoglobin
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 7
Correct
-
To which protein is T3 mostly bound in the serum?
Your Answer: Albumin
Explanation:In normal man, approximately 0.03 per cent of the total serum T4, and 0.3 per cent of the total serum T3 are present in free or unbound form. The major serum thyroid hormone-binding proteins are: 1) thyroxine-binding globulin [TBG or thyropexin], 2) transthyretin [TTR or thyroxine-binding prealbumin (TBPA)], and 3) albumin (HAS, human serum albumin). TBG has highest affinity for T4, which is 50-fold higher than that of TTR and 7,000-fold higher that of HSA. As a result TBG binds 75% of serum T4, while TTR and HSA binds only 20% and 5%, respectively.
-
This question is part of the following fields:
- Endocrinology
- Physiology
-
-
Question 8
Correct
-
Caseous necrosis is typically seen in which of the following:
Your Answer: Tuberculosis
Explanation:Caseous necrosis is most commonly seen in tuberculosis. Histologically, the complete loss of normal tissue architecture is replaced by amorphous, granular and eosinophilic tissue with a variable amount of fat and an appearance reminiscent of cottage cheese.
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 9
Incorrect
-
The pressure in the portal circulation is normally adjusted in the:
Your Answer: Portal veins
Correct Answer: Sinusoids
Explanation:The pressure in the portal circulation depends on the pressure of the hepatic sinusoids mainly because the direction of transport of nutrients in the portal vein occurs from the portal vein to the hepatic sinusoids.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 10
Incorrect
-
During uterogrowth, the second branchial arch gives rise to which structures?
Your Answer: Incus
Correct Answer: Stylohyoid muscle
Explanation:The second pharyngeal arch or hyoid arch, is the second of six pharyngeal arches that develops in fetal life during the fourth week of development and assists in forming the side and front of the neck. Derivatives: Skeletal – From the cartilage of the second arch arises: Stapes, Temporal styloid process, Stylohyoid ligament, and Lesser cornu of the hyoid bone.Muscles: Muscles of face Occipitofrontalis muscle Platysma Stylohyoid muscle Posterior belly of Digastric Stapedius muscle Auricular musclesNerve supply: Facial nerve
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 11
Incorrect
-
With regards to environmental temperature, for each degree Celsius of elevation, the metabolic rate rises?
Your Answer: 0.1
Correct Answer: 0.14
Explanation:An increase in body temperature is associated with a higher metabolic rate. Evidence suggests that an increase of 1°C in your body temperature increases your metabolism by 10 to 14%.
-
This question is part of the following fields:
- Metabolism
- Physiology
-
-
Question 12
Incorrect
-
A 43 year old lady suffering with idiopathic thrombocytopenic purpura has a splenectomy. She is advised to get the Pneumococcal vaccine booster every 5 - 10 years as Streptococcus pneumoniae has which of the following properties that make her prone to infection to this organism?
Your Answer: It is gram positive
Correct Answer: It is encapsulated
Explanation:There is a lifelong susceptibility to increased risk of infection from a variety of organisms in patients with hyposplenism, especially in children under 5 years and those with sickle cell anaemia. Patients are most susceptible is to the encapsulated bacteria Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis. Streptococcus pneumoniae is particular concerning as it can cause rapid and fulminant disease, which can be fatal. Malaria and animal bites that become infected also tend to be more severe.
-
This question is part of the following fields:
- Immunology
- Pathology
-
-
Question 13
Correct
-
A 42 year old lady has acute onset of painless weakness on her left side of the face with a drooping mouth and difficulty speaking. With no significant past medical history and after relevant investigations, you rule out stroke as a possible cause. The lady is suspected to have suffered Bell's palsy, an idiopathic paralysis of the facial nerve. What symptoms are you most likely to find on examination in a patient with Bell's palsy?
Your Answer: Taste impairment of the anterior tongue
Explanation:Bell’s palsy is facial muscle weakness or paralysis that arises from idiopathic damage to the facial nerve. It can occur at any age but is commonly associated with some conditions: 1. pregnancy 2. diabetes 3. upper respiratory ailment 4. GBS 5. Toxins The common symptoms of Bell’s palsy are: 1. Abnormal corneal reflex as the facial nerve controls the motor aspect of the corneal reflex. 2. The loss of control of facial muscles and eyelids leads to decreased tear production. 3. mild weakness to total paralysis on one side of the face, occurring within hours to days. 4. Bell’s palsy is a lower motor neuron lesion that usually spares the forehead while the upper motor near lesions, like stroke, involves the entire face. 5. The anterior two-thirds of the tongue is supplied by the chorda tympani branch of the facial nerve, thus resulting in loss of taste. 6. Ptosis can be a feature of Bell’s palsy but Bell’s palsy would typically show unilateral symptoms rather than bilateral.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 14
Incorrect
-
How many days after fertilisation does the blastocyst hatch from the zone pellucida?
Your Answer: 14-21
Correct Answer: 5-Jul
Explanation:Shortly after the morula enters the uterus, around the 4th day after fertilization, a clear cystic cavity starts forming inside the morula. The fluid passes through the zona pellucida from the uterine cavity and hence forms the blastocyst.
-
This question is part of the following fields:
- Anatomy
- Embryology
-
-
Question 15
Incorrect
-
What percentage of the cardiac output is delivered to the brain?
Your Answer: 35%
Correct Answer: 15%
Explanation:Among all body organs, the brain is most susceptible to ischaemia. Comprising of only 2.5% of total body weight, the brain receives 15% of the cardiac output. Oxygen extraction is also higher with venous oxygen levels approximating 13 vol%, and arteriovenous oxygen difference of 7 vol%.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 16
Incorrect
-
Which coronary artery supplies the right atria?
Your Answer: Left posterior descending
Correct Answer: Right coronary
Explanation:The left coronary artery distributes blood to the left side of the heart, the left atrium and ventricle, and the interventricular septum. The circumflex artery arises from the left coronary artery and follows the coronary sulcus to the left. Eventually, it will fuse with the small branches of the right coronary artery. The right coronary artery proceeds along the coronary sulcus and distributes blood to the right atrium, portions of both ventricles, and the heart conduction system.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 17
Correct
-
Which of the following features do mast cells and basophils have in common:
Your Answer: Are essential for immediate type-hypersensitivity reactions
Explanation:Anaphylaxis is a severe immediate allergic reaction of rapid onset affecting many body systems. It is due to the release of inflammatory mediators and cytokines from mast cells and basophils. Basophils are the least common of the granulocytes, representing about 0.5 to 1% of circulating white blood cells. However, they are the largest type of granulocyte. They are responsible for inflammatory reactions during immune response, as well as in the formation of acute and chronic allergic diseases, including anaphylaxis, asthma, atopic dermatitis and hay fever. They can perform phagocytosis (cell eating), produce histamine and serotonin that induce inflammation, and heparin that prevents blood clotting. Mast cells are similar in appearance and function. Both cell types store histamine, a chemical that is secreted by the cells when stimulated.
-
This question is part of the following fields:
- Immunology
- Physiology
-
-
Question 18
Incorrect
-
Concerning surface anatomy, where is the apex beat found?
Your Answer: 4th intercostal space anterior axillary line
Correct Answer: 5th intercostal space mid clavicular line
Explanation:The location of the apex beat may vary but it is mostly found in the left 5th intercostal space 6 cm from the anterior median line or in the mid clavicular line.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 19
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 20
Correct
-
The brainstem contains which of the following structures?
Your Answer: The midbrain, pons and medulla
Explanation:Brain stem is the base of the brain that connects the brain to the spinal cord. It consists of the mid brain, pons and medulla oblongata.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 21
Incorrect
-
The major factor in controlling coronary artery blood flow is considered to be?
Your Answer: Parasympathetic input
Correct Answer: Metabolites of oxygen consumption
Explanation:There is a strong relationship between myocardial blood flow and oxygen consumption. This indicates that products of metabolism may cause vasodilation of the coronary artery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 22
Incorrect
-
What is the role of factor VII in coagulation?
Your Answer: Is vitamin K independent
Correct Answer: Initiates the process of coagulation in conjunction with tissue factor
Explanation:The main role of factor VII is to initiate the process of coagulation along with tissue factor (TF). TF is found in the blood vessels and is not normally exposed to the bloodstream. When a vessel is injured tissue factor is exposed to blood and circulating factor VII. Factor VII is converted to VIIa by TF.
-
This question is part of the following fields:
- Haematology
- Physiology
-
-
Question 23
Incorrect
-
What is the result of maltase deficiency in the brush border of the small intestine?
Your Answer: Decreases rate of absorption of ingested glucose
Correct Answer: Results in increased passage of maltose in stool
Explanation:Maltase is an enzyme produced from the surface cells of the villi, lining the small intestine and aids in hydrolysing the disaccharide maltose, which splits into two molecules of α-glucose. It is done by breaking the glycosidic bond between the ‘first’ carbon of one glucose and the ‘fourth’ carbon of the other (a 1–4 bond). Hence, a deficiency of enzyme maltase will result in the increased passage of maltose in the stool.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 24
Incorrect
-
How many days after fertilisation does the morula form?
Your Answer: 2
Correct Answer: 4
Explanation:When there are about 12-32 blastomeres, the developing human is referred to as morula. It enters the uterine cavity around the 4th day after fertilization.
-
This question is part of the following fields:
- Anatomy
- Embryology
-
-
Question 25
Incorrect
-
The function of the Golgi apparatus is
Your Answer: Transport of nuclear material around the cytoplasm
Correct Answer: Maturation of peptides secreted by the rER into functional proteins by glycosylation
Explanation:Steroidogenesis is a multi-step process that occurs in two organelles, the endoplasmic reticulum (ER) and the mitochondrion. The Golgi apparatus is a major collection and dispatch station of protein products received from the endoplasmic reticulum (ER). Proteins synthesized in the ER are packaged into vesicles, which then fuse with the Golgi apparatus. The majority of proteins synthesized in the rough ER undergo glycosylation which occurs in the Golgi apparatus. Glycosylation mainly refers in particular to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules. These cargo proteins are modified and destined for secretion via exocytosis or for use in the cell. The Golgi apparatus is also involved in lipid transport and lysosome formation.
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 26
Incorrect
-
The tectum as part of the Midbrain contains which structure important in visual reflexes.
Your Answer: Red nucleus
Correct Answer: Superior colliculus
Explanation:The tectum is a part of the midbrain, specifically, the dorsal part of the midbrain. The tectum consists of the superior and inferior colliculi. The superior colliculus is involved in preliminary visual processing and control of eye movement.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 27
Incorrect
-
What is embryological origin of the pulmonary artery?
Your Answer: Second pharyngeal arch
Correct Answer: Sixth pharyngeal arch
Explanation:There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses with the sixth arch. The structures arising from the aortic arches are as follows:First aortic arch: It regresses except for a very small part that gives rise to the maxillary artery.Second aortic arch: It regresses except for a very small part giving rise to the stapedial artery.Third aortic arch: This arch is the source of the common carotid artery and the proximal part of the internal carotid artery, and the external carotid which arises as a bud from this arch.Right Fourth aortic arch: Is the genesis of the proximal part of the right subclavian artery.Left Fourth aortic arch: Gives rise to the medial portion of the arch of the aorta.Fifth aortic arch: The fifth aortic arch regresses completely and very early in the development.Sixth aortic arch: Either of the sixth aortic arches divides into ventral and dorsal segments, and therefore, their derivatives also divide into these two segments.Right Sixth Arch:Ventral: Gives rise to the right pulmonary artery.Dorsal: It degenerates completely and loses its connection with the dorsal aorta.Left Sixth ArchVentral: It gives rise to the left pulmonary artery that goes to the left pulmonary bud.Dorsal: It forms a vital connection during intrauterine life between the left pulmonary artery and the arch of the aorta. This structure is called ductus arteriosus.
-
This question is part of the following fields:
- Anatomy
- Embryology
-
-
Question 28
Correct
-
In blistering dermatological disorders e.g.. Pemphigus, which junctions are attacked by autoantibodies?
Your Answer: Desmosomes
Explanation:Pemphigus is an autoimmune disease caused by antibodies directed against both desmoglein 1 and desmoglein 3 present in desmosomes. Loss of desmosomes results in loss of cohesion between keratinocytes in the epidermis, and a disruption of the barrier function served by intact skin. The process is classified as a type II hypersensitivity reaction
-
This question is part of the following fields:
- Cell Biology
- Physiology
-
-
Question 29
Incorrect
-
Telomeres are best described as:
Your Answer: The protein end portion of DNA protecting the DNA from damage
Correct Answer: A repetitive DNA sequence at the end of a DNA molecule.
Explanation:Telomeres are non-coding DNA consisting of repetitive nucleotide sequences plus proteins that are found at the end of the linear chromosomes. They maintain the integrity of the chromosomes and prevent their shortening.
-
This question is part of the following fields:
- Genetics
- Physiology
-
-
Question 30
Correct
-
In the malaria life cycle , parasites which remain dormant in the liver are known as :
Your Answer: Hypnozoites
Explanation:The life-cycles of Plasmodium species involve several different stages both in the insect and the vertebrate host. These stages include sporozoites, which are injected by the insect vector into the vertebrate host’s blood. Sporozoites infect the host liver, giving rise to merozoites and (in some species) hypnozoites. These move into the blood where they infect red blood cells. In the red blood cells, the parasites can either form more merozoites to infect more red blood cells, or produce gametocytes which are taken up by insects which feed on the vertebrate host. In the insect host, gametocytes merge to sexually reproduce. After sexual reproduction, parasites grow into new sporozoites, which move to the insect’s salivary glands, from which they can infect a vertebrate host bitten by the insect
-
This question is part of the following fields:
- Infectious Diseases
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
