-
Question 1
Correct
-
What is the most important source of heat production in the body?
Your Answer: Skeletal muscle contraction
Explanation:Thermogenesis is the process by which organisms produce heat. Through skeletal muscle contraction, or shivering, ATP is converted into kinetic energy, some of which converts into heat. These muscle contractions produce about 70% of total body heat.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 2
Incorrect
-
What is the most important way in which heat is lost from the body?
Your Answer: Vaporisation of sweat
Correct Answer: Radiation and conduction
Explanation:The body maintains a constant core temperature by balancing heat loss and heat gain. The mechanisms of heat loss are: radiation, evaporation, convection and conduction. Out of these mechanisms, the most important under normal conditions are radiation, through which body heat is given off to the surrounding atmosphere; and conduction, in which the body releases heat into the objects it comes into contact with.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 3
Incorrect
-
What is the effect of vasopressin on the kidney?
Your Answer: Decrease collecting duct permeability to water
Correct 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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 4
Correct
-
Growth hormone deficiency causes?
Your Answer: Decreased epiphyseal growth
Explanation:Growth hormone deficiency is caused by conditions affecting the pituitary gland, such as tumours. Its effects depend on the age of the patient: in infancy and childhood, growth failure is most likely to occur. The epiphyseal plate is the area in long bones where growth occurs, and it is the area affected by growth hormone deficiency. Poor growth/shortness is the main symptom of GH deficiency in children, usually resulting in growth at about half the usual rate for age.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 5
Incorrect
-
Embryologically the anterior pituitary is formed from?
Your Answer: Endoderm
Correct 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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 6
Correct
-
What is the fat called that serves as a considerable source of heat in children?
Your Answer: Brown adipose tissue
Explanation:Brown adipose tissue, also known as BAT or brown fat, coforms the adipose tissue along with white adipose tissue (WAT) or white fat. While WAT is responsible for energy-storage, BAT is involved in thermogenesis and energy expenditure. It is more prevalent in children than in adults, and its activation during adolescence is associated to less weight gain and adiposity. BAT produces heat by non-shivering thermogenesis.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 7
Correct
-
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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 8
Incorrect
-
Choose the correct statement regarding trabecular bone:
Your Answer: Is made up of spicules/plates with a high surface to volume ratio, with many cells sitting on the surface of the end plates
Correct 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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 9
Incorrect
-
In the microanatomy of the pituitary gland, the pituicytes present are in fact modified forms of which cells?
Your Answer: Stem cells
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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 10
Incorrect
-
Which of the following factors is most likely to lead to an increase in serum cortisol levels?
Your Answer: Onset of sleep
Correct Answer: Severe emotional stress
Explanation:Cortisol is widely known as the stress hormone. Alterations in cortisol levels have been found in relation to mood disorders, illness, trauma, pain, fear, exertion, and anxiety, amongst other stimuli.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 11
Incorrect
-
What is the most abundant hormone release by the thyroid?
Your Answer: Dit
Correct Answer: T4
Explanation:T3 and T4 are the two tyrosine-based hormones produced and secreted by the thyroid gland. Although T3 is the active form of the hormone, and thus, it is much more potent; T4 is the most abundant hormone secreted by the thyroid (93% of the total thyroid secretion) and it also has a longer half life since it binds to proteins much more strongly.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 12
Incorrect
-
Select the correct statement about the microanatomy of the thyroid gland.
Your Answer: The parafollicular, or c cells, have no known function.
Correct 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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 13
Incorrect
-
Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: Ca2+ dependant ATPase
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.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 14
Incorrect
-
Regarding the structure of the 3 pituitary glycoprotein hormones FSH, LH, and TSH, which of the following is true about the α- and β-subunits of each hormone?
Your Answer: Neither subunit can form hybrids
Correct Answer: Maximal physiological activity occurs only on their combination
Explanation:Glycoprotein hormones (GPHs) are the most complex molecules that function as hormones. They each consist of two different subunits, α and β, which are non-covalently associated. The combination of these subunits results in an increase in their activity and β structure.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 15
Incorrect
-
Which is primarily responsible for the conversion of T4 to T3 in the periphery?
Your Answer: Deiodinase 3
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 is 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
- Medicine
-
-
Question 16
Incorrect
-
To which protein is T3 mostly bound in the serum?
Your Answer: Albumin
Correct Answer: Thyroxin-binding globulin
Explanation:In a normal person, 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 Albumin 5%, respectively.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 17
Correct
-
Phosphate absorption in the proximal tubules is via which transporting molecule?
Your Answer: Na/Pi co transporter
Explanation:Sodium/phosphate cotransporters are located in the renal proximal tubular brush border, and are the key elements in proximal tubular phosphate reabsorption and phosphate homeostasis.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 18
Incorrect
-
A 14-year-old girl presents with short stature, webbed neck and primary amenorrhoea.Given the likely clinical diagnosis, which hormone replacement is most crucial over the longer term?
Your Answer: Growth hormone
Correct Answer: Oestrogen
Explanation:This girl most likely has Turner syndrome (TS) also known as 45,X, a condition in which a female is partly or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, they are without menstrual periods, do not develop breasts, and are unable to have children. Heart defects, diabetes, and low thyroid hormone occur more frequently. Most people with TS have normal intelligence. Many, however, have troubles with spatial visualization such as that needed for mathematics. Vision and hearing problems occur more often. Turner syndrome is not usually inherited from a person’s parents. No environmental risks are known and the mother’s age does not play a role. As a chromosomal condition, there is no cure for Turner syndrome. However, much can be done to minimize the symptoms including prescribing growth hormone, either alone or with a low dose of androgen, and oestrogen replacement therapy which is crucial long term for maintaining good bone integrity, cardiovascular health and tissue health
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 19
Incorrect
-
Which of the following describes a principal action of insulin?
Your Answer: Stimulation of the release of free fatty acids from adipose tissue
Correct Answer: Inhibition of phosphorylase and gluconeogenic enzymes
Explanation:Insulin stimulates glycolysis and lipogenesis, but inhibits gluconeogenesis. Insulin promotes the dephosphorylating of glycogen phosphorylase, therefore suppressing glycogenolysis. Insulin also inhibits FOX3, FOX4, and FOX6 and their ability to promote hepatic gluconeogenesis.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
-
Question 20
Incorrect
-
Compact/cortical bone makes up
Your Answer:
Correct Answer: The outer layer of most bones and accounts for 80% of bone in the body
Explanation:Cortical, lamellar, or compact bone, is more dense than spongy bone and it forms the rigid, outer layer of bones, also called cortex. It consists of packed osteons, with a central osteonic canal surrounded by concentric rings. Spaces called lacunae are filled with osteocytes, and channels called canaliculi go from the lacunae to the osteonic canal. The strength of cortical bone allows it to support the body and protect organs. It also stores different elements, such as calcium.
-
This question is part of the following fields:
- Endocrinology
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
