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Question 1
Correct
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Choose the correct statement regarding trabecular bone:
Your Answer: All of the options are correct
Explanation:Trabecular, spongy or cancellous bone. It is located inside the cortical bone and makes up around 20% of all bone in the body. It is made of spicules or plates with a high surface to volume ratio, where many cells sit on the surface of the end plates. It receives its nutrients from the extracellular fluid (ECF), exchanging about 10 mmol of calcium every 24 hours.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 2
Correct
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Pendrin is a Cl-/I- exchanger whose function is:
Your Answer: Transfer of iodide across the thyrocyte apical membrane into the colloid
Explanation:Pendrin is an anion transporter present in the inner ear, thyroid and kidney. It regulates the entrance of iodide from the thyroid cell to the colloid space. It has been proposed that its role could be the maintenance of the ionic composition of the endolymph.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 3
Correct
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Which of the following structures lie in close proximity to the thyroid?
Your Answer: All of the options
Explanation:The thyroid gland receives its blood supply from the inferior and superior thyroid arteries. The recurrent laryngeal nerves emerges from the superior thoracic outlet bounded in part by the thyroid lobe. Two pairs of parathyroid glands lie near the thyroid. The common carotid artery splits into its external and internal branches at the upper border of the thyroid cartilage; these branches are separated by the gland.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 4
Correct
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The action of progesterone on different organs/systems includes:
Your Answer: Breasts: stimulation of lobular and alveolar development
Explanation:Progesterone is a sex hormone which affects mainly the reproductive system. In the breasts, it mediates the lobuloalveolar maturation to allow for milk production; this is done in conjunction with prolactin. It acts to maintain female reproductive and sex characteristics.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 5
Correct
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In the menstrual cycle, ovulation is triggered by:
Your Answer: A pituitary LH surge due to the positive feedback effect of circulating oestrogens
Explanation:FSH and LH are secreted to start the development of a follicle at the start of each menstrual cycle. A surge in oestrogen causes a positive feedback in the LH cells of the pituitary; this causes ovulation.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 6
Incorrect
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In which of the following are the enzymatic mechanisms for producing aldosterone found?
Your Answer: Zona fasciculate
Correct Answer: Zona glomerulosa
Explanation:The zona glomerulosa is the outermost layer of the adrenal gland. In it, aldosterone is secreted as a response to an increase in potassium levels, decreased blood flow, or renin. This secretion is regulated by the renin-angiotensin system.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 7
Correct
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Which one of the following leads to decreased prolactin levels?
Your Answer: Dopamine
Explanation:Dopamine has an important effect on the regulation of prolactin secretion. Dopamine binds to type-2 dopamine receptors of the lactotroph cells that are functionally linked to membrane channels and G proteins and suppresses the high secretory activity of the pituitary lactotrophs.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 8
Correct
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In the absence of insulin:
Your Answer: Glucose uptake by most of the brain is normal
Explanation:Although it is known that insulin levels affect glucose uptake, oxidation and storage in peripheral tissues, its role in the brain isn’t as clear. However, studies have shown that bulk brain glucose uptake isn’t affected by insulin. Glucose transport into the neurons is GLUT3 dependent, and its transport into glia and brain endothelial cells rely on GLUT1. Insulin isn’t necessary for GLUT1 or GLUT3, which explains why brain glucose uptake isn’t affected by insulin levels.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 9
Incorrect
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Within the hypothalamus, the dopamine-secreting neurones of the intrahypothalamic system have their cell bodies in which nuclei?
Your Answer: Supraoptic
Correct Answer: Arcuate
Explanation:Arcuate nucleus dopaminergic neurons consist of a single group of neurons that project to the median eminence where they release dopamine into the hypophyseal portal circulation to inhibit pituitary prolactin secretion.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 10
Incorrect
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Which of the following derivatives of proopiomelanocortin is an opioid peptide?
Your Answer: Melanotropins
Correct Answer: ß-endorphin
Explanation:ß-endorphin is an endogenous opioid neuropeptide which is mainly synthesized and stored in the anterior pituitary gland, derived from the precursor proopiomelanocortin (POMC). Some studies have shown that immune system cells are also capable of synthesizing ß-endorphin. β-endorphin is thought to exert a tonic inhibitory influence upon GNRH secretion and to be an important regulator of reproductive function.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 11
Correct
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The residual cleft of the intermediate lobe of the pituitary is lined by follicles resembling which human gland?
Your Answer: Thyroid
Explanation:The cells located between the two main pituitary lobes form what is known as the intermediate pituitary. This area secretes melanocyte-stimulating hormone and it is only a few cell layers thick. It is rich in follicles filled with colloid, and lined by basophilic cells. This configuration resembles that of another important gland: the thyroid.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 12
Incorrect
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What is the primary cause of ketoacidosis in Type 1 diabetes?
Your Answer: Glycogenolysis
Correct Answer: Lipolysis
Explanation:in type 1 diabetics the lack of insulin in the bloodstream prevents glucose absorption, thereby inhibiting the production of oxaloacetate (a crucial precursor to the β-oxidation of fatty acids) through reduced levels of pyruvate (a by-product of glycolysis), and can cause unchecked ketone body production (through fatty acid metabolism or lipolysis) potentially leading to dangerous glucose and ketone levels in the blood.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 13
Incorrect
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In a newly diagnosed acromegaly patient, which of the following would you not expect to find?
Your Answer: Carpal tunnel syndrome
Correct Answer: Hypohidrosis
Explanation:Features of acromegaly may include:
- Soft tissue swelling visibly resulting in enlargement of the hands, feet, nose, lips and ears, and a general thickening of the skin
- Soft tissue swelling of internal organs, notably the heart with associated weakening of its muscularity, and the kidneys, vocal cords (resulting in a characteristic thick, deep voice and slowing of speech)
- Generalized expansion of the skull at the fontanelle, frontal bossing, prognathism with associated macroglossia (enlargement of the tongue) and teeth spacing.
- Hypertrichosis, hyperpigmentation and hyperhidrosis (not hypohidrosis) may occur in these patients as well as carpal tunnel syndrome and impotence.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 14
Correct
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What causes increased insulin sensitivity?
Your Answer: Exercise
Explanation:Physical activity, through its effect on insulin sensitivity, is one of the main modifiable risk factors for type 2 diabetes. It is estimated that by each weekly 500 kcal increment in exercise related energy consumption, the lifetime risk of suffering from type 2 diabetes is reduced by 9%. Up to two hours after exercise, glucose uptake is elevated due to insulin independent mechanisms; however, insulin sensitivity remains increased for at least 16 hours after exercising.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 15
Correct
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The net effect of active Vitamin D on calcium and phosphate homeostasis is?
Your Answer: Increase in Ca, increase in phosphate
Explanation:Bone and its metabolism are regulated by several hormones, amongst which is vitamin D. It is heavily involved in the metabolism and homeostasis of calcium and phosphate through several processes. Vitamin D works in the intestine, kidney, bone and parathyroid glands to maintain levels of calcium and phosphate, promoting its absorption, bone resorption, and proper functioning of the parathyroid to maintain adequate serum calcium levels.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 16
Correct
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Embryologically the anterior pituitary is formed from?
Your Answer: Rathkes pouch
Explanation:The ectoderm, located in the roof of the pharynx, forms Rathke’s pouch, which comes into contact with the ectoderm of the developing brain. The pouch eventually separates from the pharynx, becoming the anterior pituitary.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 17
Correct
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Which of the following features is least commonly seen in Gitelman’s syndrome?
Your Answer: Hypertension
Explanation:Gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalaemia metabolic alkalosis with hypocalciuria, and hypomagnesemia. In contrast to patients with Gordon’s syndrome, those suffering from Gitelman’s syndrome are generally normotensive or hypotensive.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 18
Incorrect
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Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: Calcium / Na+ exchanger
Correct Answer: TRPV 6
Explanation:Transient Receptor Potential Vanilloid 6 or TRPV 6 is a calcium channel located in the cell membrane which is present in a variety of organs, including small intestine, oesophagus, stomach, colon, placenta, kidney, and uterus. In the intestine, it is located in the apical brush-border membrane of the enterocyte, regulating the entry of calcium into the cell.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 19
Incorrect
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What microscopic changes are visible in an active thyroid gland?
Your Answer: Colloid is abundant.
Correct Answer: Follicle lining cells are cuboid or columnar.
Explanation:Active follicles are lined by cuboidal or columnar cells; this is because active follicles are smaller and have less colloid. Their cells are tall because they are actively secreting hormones, whereas older follicles have a flat epithelium and are filled with more colloid.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 20
Correct
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Where does the anterior pituitary receive most of its blood supply?
Your Answer: Portal hypophysial vessels
Explanation:The anterior pituitary receives its arterial supply from the superior hypophyseal artery, which is a branch of the internal carotid that forms a capillary around the hypothalamus; thus forming the hypothalamo-hypophysial portal system.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 21
Incorrect
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In the microanatomy of the pituitary gland, the pituicytes present are in fact modified forms of which cells?
Your Answer: Fibroblasts
Correct Answer: Astrocytes
Explanation:Pituicytes are glial cells present in the pars nervosa, the posterior pituitary gland. Their irregular shape resembles that of astrocytes, and their cytoplasm also has intermediate filaments. They differ from astrocytes in that they have large cytoplasmic lipid droplets.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 22
Correct
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Select the correct statement about the microanatomy of the thyroid gland.
Your Answer: The capillaries adjacent to thyroid cells have a fenestrated endothelium.
Explanation:Fenestrated capillaries have a very thin endothelium, which is perforated by numerous fenestrations or pores. Hormones are usually released into these capillaries, reaching their target cells through the circulatory system.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 23
Incorrect
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The growth promoting protein anabolic effects of insulin are mediated by:
Your Answer: Igf-1
Correct Answer: Phosphatidylinositol 3-kinase
Explanation:Phosphatidylinositol 3-kinase or PI-3Ks are a group of enzymes which are involved in a number of different cellular functions. PI-3Ks interact with insulin and the insulin receptor substrate, regulating glucose uptake. They are an important element in the insulin signalling pathway.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 24
Correct
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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: 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.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 25
Incorrect
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Which of the following biochemical profiles is seen in a normal 65 year old female? (in comparison to a normal 24 yr. old female)
Your Answer: Increased FSH, LH; increased oestrogen, progesterone
Correct Answer: Increased FSH, LH; decreased oestrogen, progesterone
Explanation:During menopause, a woman’s number of ovarian follicles becomes depleted; as a result, oestrogen and progesterone levels drop, and LH and FSH levels increase. One of the criteria to diagnose menopause is the absence of menstrual period for a year, along with a serum FSH level increased to 30 mIU/ml or higher. LH also rises with the onset of menopause.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 26
Incorrect
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The net effect of parathyroid hormone on calcium and phosphate homeostasis is?
Your Answer: Increase in Ca , increase in phosphate
Correct Answer: Increase in Ca, decrease in phosphate
Explanation:Parathyroid hormone’s main target organs are the kidneys, bone, and intestine. In the kidney, it decreases reabsorption of phosphate and increases calcium reabsorption. It also promotes absorption of calcium from bone. PTH release results in a small drop in serum phosphate concentrations.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 27
Correct
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Which cells secrete insulin?
Your Answer: B cells of the pancreatic islets
Explanation:Insulin is synthesised and stored by the B cells of the pancreatic islets (70% of islet cells), glucagon is synthesised and stored in the A cells (20%) and somatostatin is synthesised and stored in the D cells (10%).
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 28
Correct
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What is the effect of oxytocin on the breast?
Your Answer: Milk ejection
Explanation:Oxytocin is a peptide hormone and neuropeptide, produced by the hypothalamus and released by the posterior pituitary. It causes the milk ejection or let-down reflex, causing the milk to be transported to the subareolar sinuses, allowing it to be released through the nipple. This response is initiated by the act of suckling by the baby, but it can be conditioned to be triggered by different stimuli.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 29
Correct
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Which of the following is correctly paired?
Your Answer: F cells : pancreatic polypeptide
Explanation:Pancreatic polypeptide is secreted by F-cells, which represent the smallest proportion of islet cells in the pancreas. These cells establish the embryological origin of the pancreas. Pancreatic polypeptide regulates endocrine and exocrine activities by the pancreas.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 30
Correct
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What is the effect of vasopressin on the kidney?
Your Answer: Increase collecting duct permeability to water
Explanation:Vasopressin, also known as antidiuretic hormone or ADH, which increases water reabsorption in the kidney’s collecting ducts. It works by increasing water permeability in the collecting ducts and distal convoluted tubules. It induces the exocytosis of AQP-CD-laden vesicles, transferring water channels from intracellular vesicles to the apical plasma membrane, therefore allowing more water to be reabsorbed from the urine in the collecting ducts to the blood.
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This question is part of the following fields:
- Endocrinology
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
