Term
1. Acidophils of the pituitary gland contain the following cells producing GH and PRL(prolactin), respectively:
A. Lactotropes and gonadotropes
B. Somatomammotropes and thyrotropes
C. Corticotropes and mammotropes
D. Somatotropes and lactotropes
E. Luteotropes and folliculotropes |
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Definition
| D. Somatotropes and lactotropes |
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Term
| 2. The pituitary gland has a dual embryonic origin. The posterior lobe (neurohypophysis) of the pituitary develops from the _______________ (see figure below): A. ME B. trophoblast C. Rathke’s pouch D. hypothalamic neuroectoderm E. oropharynx ectoderm |
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Definition
| D. hypothalamic neuroectoderm |
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Term
3. Axons of the neuronal lobe:
A. are connected morphologically with the hypothalamus by the portal hypophyseal system of blood vessels.
B. comprise hormone-storing terminals of secretory neurons located in the SO and PV nuclei of the hypothalamus.
C. contain large dilatations that store the hormones; these are visible with light microscope and referred to as pituicytes.
D. form numerous synaptic connections but never run in the proximity of sinusoidal capillaries.
E. are collectively called the pars glandularis. |
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Definition
| B. comprise hormone-storing terminals of secretory neurons located in the SO and PV nuclei of the hypothalamus. |
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Term
4. Which is TRUE for the pituitary gland?
A. The pars nervosa consists of the clusters of protein producing cells, which are characterized
by different affinity for various dyes (i.e., acidophils, basophils and chromophobes).
B. Corticotropes produce ACTH and Beta-lipotropin.
C. TRH and ACTH are produced in the neurons of the hypothalamus.
D. In most domestic animals, the pars intermedia is separated from the pars nervosa by a
hypophyseal cleft and is closely associated with the pars distalis.
E. Melanotropes (cells producing MSH) are most abundant in the pars distalis and are usually
referred to as the Herring bodies. |
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Definition
| B. Corticotropes produce ACTH and Beta-lipotropin. |
|
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Term
5. Which of the following conditions is associated with hyposecretion of GH in growing, or
prepubertal, animals and human beings?
A. Dwarfism
B. Pituitary gigantism
C. Cretinism
D. Acromegaly
E. Alopecia |
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Definition
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Term
6. Which is NOT true for the thyroid gland?
A. Thyroid follicles are small vesicles filled with colloid and lined by a single layer of follicular
cells.
B. In active, secreting follicles, follicular cells are squamous, and colloid is dense and uniform.
C. Follicular cells secrete thyroglobulin into the colloid where peroxidase is responsible for
iodination of thyroglobulin.
D. TSH regulates nearly all aspects of the biosynthesis and release of T3 and T4 from the follicular cells.
E. Numerous small secretory granules in the parafollicular cells (C cells) contain calcitonin (thyrocalcitonin). |
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Definition
| B. In active, secreting follicles, follicular cells are squamous, and colloid is dense and uniform. |
|
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Term
7. The “iodine trapping” refers to:
A. the sodium/iodine symporter system of thyrocytes.
B. the mechanism by which target cells take up thyroid hormones from the blood.
C. the process by which thyroid hormones are released from thyroglobulin.
D. the process by which thyroglobulin is iodinated and condensation takes place.
E. the absorption of iodide by the GI tract. |
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Definition
| A. the sodium/iodine symporter system of thyrocytes. |
|
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Term
8. The most abundant product secreted from the thyroid gland is _______________ and the most
potent thyroid secretory product is ______________.
A. T4; MIT
B. T4; T4
C. DIT; T3
D. T3; T4
E. T4; T3 |
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Definition
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Term
9. Thyroid hormones:
A. are essential for normal development of the central nervous system.
B. selectively decrease the metabolic rate (oxygen consumption) in target organs.
C. their secretion is decreased in response to low temperature.
D. increase TSH secretion.
E. increase TRH secretion. |
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Definition
| A. are essential for normal development of the central nervous system. |
|
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Term
10. Which of the following statements concerning the synthesis of thyroid hormones is INCORRECT?
A. The iodine transport by the thyrocytes is important for thyroid hormone biosynthesis.
B. Thyroid hormones are formed within a much larger molecule called thyroglobulin.
C. A 1-2−hour supply of thyroid hormones is stored within the colloid in the lumen of thyroid follicles.
D. The coupling of two DIT molecules yields T4.
E. The coupling of one MIT molecule and one DIT molecule yields triiodothyronine (T3). |
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Definition
| C. A 1-2−hour supply of thyroid hormones is stored within the colloid in the lumen of thyroid follicles. |
|
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Term
11. The approximate T4 : T3 ratio in peripheral circulation (blood plasma) in dogs and humans is:
A. 1 : 4
B. 4 : 1
C. 1 : 1
D. 1 : 20
E. 20 : 1 |
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Definition
| E. 20 : 1 (T4 is more abundant, T3 is more potent) |
|
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Term
12. To treat primary hypothyroidism, thyroxin is generally used rather than triiodothyronine
because:
A. T4 is more potent than T3
B. T4 does not inhibit TRH secretion
C. T4 has a longer biological half-life than T3
D. T4 has a shorter biological half-life than T3
E. T4 does not bind to TBG |
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Definition
| C. T4 has a longer biological half-life than T3 |
|
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Term
13. The primary factor governing the hormonal regulation of calcium homeostasis is:
A. the content of total calcium in bone mineral.
B. the concentration of total calcium in diet.
C. the concentration of ionized calcium in blood.
D. the concentration of total calcium in the feces.
E. the concentration of ionized calcium in urine. |
|
Definition
| C. the concentration of ionized calcium in blood. |
|
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Term
14. A hormone that promotes bone resorption is:
A. estrogen
B. 24, 25 (OH)2 vitamin D3
C. calcitonin
D. IGF-1
E. PTH |
|
Definition
E. PTH (parathyroid)
Calcitonin transports calcium to bone "tones bone" |
|
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Term
15. Which of the following has an antagonistic action to that of PTH?
A. ACTH
B. CRF
C. Aldosterone
D. Thyrocalcitonin
E. T4 |
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Definition
|
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Term
16. The main steroid hormones produced by the zona reticularis of the adrenal cortex are:
A. glucocorticoids
B. androgens
C. mineralocorticoids
D. somatomedins
E. all of the above hormones are produced by the zona reticularis |
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Definition
|
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Term
17. The secretion of which one of the following adrenal steroids would NOT be affected by
hypophysectomy (i.e., surgical dissection of the pituitary gland)?
A. Aldosterone
B. Cortisol
C. Corticosterone
D. Pregnenolone
E. Dehydroepiandrosterone |
|
Definition
|
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Term
18. Which of the following steps in steroid hormone biosynthesis does NOT take place in
mitochondria?
A. Conversion of cholesterol to pregnenolone
B. Conversion of pregnenolone to progesterone
C. Conversion of 11-deoxycortisol to cortisol
D. Conversion of corticosterone to 18OH-corticosterone
E. Conversion of 18OH-corticosterone to aldosterone |
|
Definition
| B. Conversion of pregnenolone to progesterone |
|
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Term
19. The process whereby more potent steroids are converted into steroids with lower biological
activity and greater water solubility is known as:
A. Conjugation
B. Excretion
C. Sulphation
D. Glycosylation
E. Biotransformation |
|
Definition
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Term
20. Catecholamines are synthesized in the adrenal medulla under the influence of:
A. ACTH
B. sympathetic system neurons
C. parasympathetic nervous system
D. CRH
E. cortisol |
|
Definition
| B. sympathetic system neurons |
|
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Term
21. The hormone _______________, secreted by the heart, has the exact opposite function to the
hormone _______________, which is secreted by the _______________ region of the adrenal
cortex.
A. ANP - aldosterone - zona glomerulosa
B. aldosterone - cortisol - zona fasciculata
C. ADH - cortisol - zona glomerulosa
D. ANP - cortisol - zona fasciculata
E. cortisol - aldosterone - zona reticularis |
|
Definition
| A. ANP - aldosterone - zona glomerulosa |
|
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Term
| 22. Insulin: A. is secreted by the Beta cells of the pancreatic islets B. is essential for the uptake of glucose by brain tissue C. promotes glucose output by the liver D. lowers blood glucose levels E. promotes glycogenolysis by hepatocytes |
|
Definition
| D. lowers blood glucose levels |
|
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Term
23. Chemical blockers of thyroid hormone synthesis that decrease thyroglobulin iodination and
conversion of thyroxin (T4) to triiodothyronine (T3) are:
A. furosemides
B. goitrogens
C. thiocarbamides
D. only A
E. B and C |
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Definition
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Term
24. Aldosterone secretion:
A. occurs in the kidney.
B. is stimulated by Angiotensin II.
C. is controlled by plasma concentration of calcium.
D. is regulated mainly by ACTH.
E. None of the above. |
|
Definition
| B. is stimulated by Angiotensin II. |
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Term
25. Which of the following is/are NOT associated with responses to catecholamines as part of
the primary stress response?
A. Increased heart rate
B. Increased hepatic gluconeogenesis
C. Increased sweating
D. Increased water retention and increased blood pressure
E. Dilation of blood vessels in heart and brain |
|
Definition
| B. Increased hepatic gluconeogenesis |
|
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Term
26. Which of the following processes are involved in the clearance and excretion of steroid
hormones from the mammalian body?
A. Monodeiodination.
B. Conjugation with sulphate.
C. Conjugation with glucuronic acid.
D. Hydroxylation to make more soluble forms of steroids.
E. Answers B, C and D are all correct. |
|
Definition
| E. Answers B, C and D are all correct. |
|
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Term
27. Apart from _____________ , insulin stimulates the uptake of glucose by many tissues:
A. adipose tissue
B. liver
C. exercising muscle and brain tissue
D. exercising muscle
E. brain tissue |
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Definition
| C. exercising muscle and brain tissue |
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Term
28. Which of the following does NOT play a role in K+ recovery in the kidney?
A. ADH
B. Ang II
C. ANP
D. Aldosterone
E. Renin |
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Definition
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Term
30. Which of the following biochemical events does NOT take place within the thyroid gland
during hormone synthesis?
A. Four iodide molecules combine with one tyrosine molecule to form one
tetraiodothyronine compound.
B. Two iodine molecules combine with one tyrosine molecule to form one DIT molecule.
C. Two DIT molecules combine to form one molecule of T4.
D. One MIT molecule combines with one DIT molecule to form T3.
E. Oxidation of iodide to form a free radical that combines with thyroglobulin. |
|
Definition
A. Four iodide molecules combine with one tyrosine molecule to form one
tetraiodothyronine compound. |
|
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Term
31. Which of the following is NOT an action of cortisol?
A. It increases the conversion of glycogen to glucose.
B. It stimulates hepatic gluconeogenesis.
C. It increases protein breakdown in skin, lymphoid tissue and muscle.
D. It mobilizes lipids from adipocytes.
E. It suppresses inflammation. |
|
Definition
| A. It increases the conversion of glycogen to glucose. |
|
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Term
32. Which of the following hormones does NOT directly or indirectly promote growth?
A. GH
B. Androgens
C. T3
D. Cortisol
E. Insulin |
|
Definition
| D. Cortisol - encourages protein and lipid mobilization, not growth. |
|
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Term
33. Which of the following statements concerning the action of PTH is
FALSE?
A. Elevated plasma Ca2+ concentrations act directly on the parathyroid gland to stimulate PTH secretion.
B. PTH promotes the rapid movement of Ca2+ from the bone fluid into the plasma.
C. PTH promotes the localized dissolution of bone by stimulating osteoclasts.
D. PTH helps the kidneys remove excess phosphate from the body.
E. PTH stimulates the activation of vitamin D3. |
|
Definition
| A. Elevated plasma Ca2+ concentrations act directly on the parathyroid gland to stimulate PTH secretion. |
|
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Term
34. Accessory thyroid tissue in dogs can frequently be found in:
A. the brain
B. the lungs
C. the abdomen
D. the mediastinum
E. the pericardium |
|
Definition
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Term
35. Thyroid-stimulating hormone (TSH) receptors are:
A. G-protein coupled receptors
B. ionic channels
C. tyrosine kinase receptors
D. cytokine receptors
E. nuclear receptors |
|
Definition
| A. G-protein coupled receptors |
|
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Term
36. The euthyroid sick syndrome (ESS) is due mainly to altered biosynthesis and/or activity of
the:
A. thyroid peroxidase
B. thyroglobulin
C. thyroxin binding globulin
D. deiodinases
E. TRIAC and TATRAC enzymes |
|
Definition
|
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Term
37. The main clinical reason (ethiology) for the primary hypothyroidism in dogs appears to be:
A. cancer
B. thyroiditis
C. idiopathic follicular atrophy
D. thyrotoxicosis
E. iodine deficiency |
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Definition
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Term
38. The net daily intake of Ca2+ from the gastrointestinal tract typically comprises:
A. 10% of dietary calcium content.
B. 20% of dietary calcium content.
C. 50% of dietary calcium content.
D. 75% of dietary calcium content.
E. nearly 100% of Ca2+ from the diet. |
|
Definition
| A. 10% of dietary calcium content. |
|
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Term
39. Which of the following is TRUE for calcitonin?
A. It is a peptide produced by the parathyroid gland.
B. Compared to parathyroid hormone (PTH), it is a long-acting hormone.
C. It is secreted in response to hypocalcaemia.
D. It reduces calcium and phosphate reabsorption in the kidney.
E. It suppresses bone formation. |
|
Definition
D. It reduces calcium and phosphate reabsorption in the kidney.
(An overabundance of Ca in the blood leads to transport to the bone and increased excretion) |
|
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Term
40. Cholecalciferol (vitamin D3) is converted in the liver to a more potent form:
A. 1,25-dihydroxy cholecalciferol
B. 24,25-dihydroxy cholecalciferol
C. 25-hydroxy cholecalciferol
D. 7-dehydrocholesterol
E. cholesterol |
|
Definition
| C. 25-hydroxy cholecalciferol |
|
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Term
41. The active, transcellular transport of Ca2+ from the gut occurs mainly in the:
A. jejunum
B. Ileum
C. colon
D. duodenum
E. rectum |
|
Definition
|
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Term
42. Which is/are NOT a typical clinical sign of hyperparathyroidism (excess PTH production)?
A. Hypercalcaemia (elevated blood calcium levels)
B. Increased bone resorption/fractures
C. Calcification of soft tissues
D. Increased thirst and urine production
E. Cardiac arrhythmias |
|
Definition
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Term
43. If “House temperature falls” = “serum Ca++ rises” than “Response system [home furnace]
switched on” = _________________.
A. Increased Ca++ absorption in the jejunum
B. PTH secretion increases
C. Increased activity of osteoclasts
D. Decreased glomerular filtration of Ca++
E. None of the above |
|
Definition
|
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Term
44. If “House temperature falls” = “serum Ca++ declines” than “Response system [furnace]
switched on” = _________________.
A. Increased secretion of thyrocalcitonin
B. Decreased synthesis and activity of parathyroid hormone (PTH)
C. Increased activity of osteoclasts
D. Decreased Ca++ absorption from glomerular filtrate
E. None of the above |
|
Definition
| C. Increased activity of osteoclasts |
|
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Term
45. Homeostatic regulation is the conceptual framework for studying endocrine physiology.
Who coined the term “homeostasis”?
A. Aristotle (384 BC-322 BC)
B. Claude Bernard (1813-1878)
C. Ernest Starling (1866-1927)
D. Walter Cannon (1871-1945)
E. Jeff Thomason (1980-present) |
|
Definition
| D. Walter Cannon (1871-1945) |
|
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Term
47. The correct order of adrenocortical zones (from external to internal) is:
A. glomerulosa-fasciculata-reticularis
B. fasciculata-reticularis-glomerulosa
C. reticularis-fasciculata-glomerulosa
D. fasciculata-glomerulosa-reticularis
E. glomerulosa-reticularis-fasciculata |
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Definition
| A. glomerulosa-fasciculata-reticularis |
|
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Term
48. Angiotensin I is converted to the octapeptide, Angiotensin II, by an angiotensin converting
enzyme present in the:
A. juxtaglomerular apparatus
B. macula densa
C. capillary endothelial cells of the lungs
D. liver
E. None of the above |
|
Definition
| C. capillary endothelial cells of the lungs |
|
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Term
49. The approximate half-life of insulin is:
A. < 1 minute
B. 3-5 minutes
C. 30 minutes
D. 1 hour
E. >1 hour |
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Definition
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