Deck 19: The Peripheral Endocrine Glands

Question 1

Which statement is incorrect?

A)The "iodide pump" of the follicular cells is important for thyroid hormone production.
B)Thyroid hormones are formed within a much larger molecule called thyroglobulin.
C)Thyroid hormone synthesis is greatly stimulated by the presence of TSH.
D)A two-hour supply of thyroid hormone is stored in the lumen of the thyroid follicles.
E)The coupling of two DIT molecules yields thyroxine.

Answer 1

D

Question 2

The "iodide pump" refers to the

A)mechanism whereby target cells extract iodine-containing thyroid hormone from the blood
B)active transport mechanism that concentrates iodide ions in the thyroid
C)mechanism whereby T3 and T4 are released from thyroglobulin and pumped into the circulation
D)protein binding process whereby T3 and T4 are pumped throughout the body bound to plasma proteins
E)mechanism whereby ingested iodine is absorbed by the small intestine

Answer 2

B

Question 3

__________ would not decrease thyroid hormone production.

A)A decrease in TSH production
B)An iodine deficient diet
C)An increase in TRH production
D)Inhibition of the iodide pump
E)Removal of the pituitary

Answer 3

C

Question 4

Most of the secreted T₄ is

A)phagocytized by target tissues
B)converted into T3 after being peripherally stripped of one of its iodine atoms
C)able to function as the biologically active form of thyroid hormone at the cellular level
D)split to form two DIT molecules, which are excreted in the urine
E)able to exert its full biological effect as a result of epinephrine's permissive actions

Question 5

Thyroid hormones

A)regulate basal metabolic rate
B)are released from the thyroid gland immediately after synthesis
C)contain chromium and zinc as structural cofactors
D)are tropic
E)are none of the above

Question 6

Thyroid hormone does not

A)increase metabolic rate
B)increase tissue responsiveness to catecholamines
C)increase absorption of iodine from the digestive tract into the blood
D)promote normal growth
E)promote normal development of the nervous system

Question 7

TSH

A)secretion is stimulated by thyrotropin-releasing hormone (TRH)
B)secretion is inhibited by T3 and T4
C)increases the rate of thyroid hormone secretion
D)promotes hypertrophy and hyperplasia of thyroid cells
E)has all of the above characteristics

Question 8

During thyroid hormone secretion,

A)the follicular cells phagocytize a piece of colloid
B)T4 and T3 are removed from thyroglobulin by lysosomal enzymes in the follicular cell; then they diffuse out of the cell and into the blood
C)T4 and T3 are secreted by exocytosis of the colloid that has been internalized by the follicular cells
D)both a and b occur
E)both b and c occur

Question 9

Thyroid-stimulating immunoglobulin is

A)able to stimulate production of T3 and T4 secretion by the thyroid
B)inhibited by T3 and T4 in a negative-feedback fashion
C)found in all people but is present in excessive amounts in people with Grave's disease
D)both a and c
E)both b and c

Question 10

Thyroid hormone causes

A)the pituitary to release less TSH
B)TRH to be secreted, which in turn stimulates T3 and T4 release
C)the hypothalamus to release more TRH
D)the thyroid to release even more thyroid hormone
E)both b and c

Question 11

Thyroid hormones are

A)derivatives of an amino acid
B)produced from tyrosine
C)stored on thyroglobulin within the follicular colloid
D)all of the above
E)only a and b

Question 12

Hyperthyroidism can be due to all of the following except

A)too much TRH
B)too much TSH
C)lack of iodine
D)LATS
E)thyroid-stimulating immunoglobulin

Question 13

Thyroxine (T₄)

A)is formed by coupling one MIT and one DIT within the colloid
B)is produced by the C cells of the thyroid gland
C)is usually converted to T3 in the liver and kidneys
D)inhibits thyroid-stimulating immunoglobulin in negative-feedback fashion
E)is more potent than tri-iodothyronine

Question 14

The endocrine gland that secretes hormones containing iodine is the

A)adrenal cortex
B)adrenal medulla
C)pancreas
D)thyroid
E)thymus.

Question 15

___________ targets osteoclasts when blood calcium levels are too low, thus causing an increase in the concentration of calcium in the blood?

A)Aldosterone
B)Thyroid hormone
C)Cortisol
D)Parathyroid hormone
E)Calcitonin

Question 16

Which of the following are plasma proteins to which thyroid hormone is bound in circulation?

A)albumin
B)gamma globulin
C)thyroxine-binding globulin
D)Both a and b
E)Both a and c

Question 17

Which biochemical event does not take place during thyroid hormone synthesis?

A)One monoiodotyrosine molecule combines with one di-iodotyrosine molecule to form one tri-iodothyronine molecule.
B)Two iodine molecules combine with one tyrosine molecule to form one di-iodotyrosine molecule.
C)Two di-iodotyrosine molecules combine to form one molecule of thyroxine.
D)Four iodine molecules combine with one tyrosine molecule to form one tetraiodothyronine molecule.
E)None of the above take place

Question 18

Tri-iodothyronine does not

A)increase the overall metabolic rate
B)exert a calorigenic effect
C)bind to receptors on the surface of all body cells
D)enhance glycogenolysis and lipolysis
E)cause a proliferation of specific catecholamine target-cell receptors

Question 19

Which is not true about Grave's disease?

A)It may produce exophthalmos.
B)It is an autoimmune disease.
C)It produces a goiter.
D)It causes an elevated basal metabolic rate.
E)It is the most common form of hyperthyroidism.

Question 20

Hormones produced by the thyroid include

A)calcitonin
B)thyroxine
C)PTH
D)a and b
E)b and c

Question 21

The precursor to testosterone is

A)aldosterone
B)cortisol
C)dehydroepiandrosterone
D)estradiol
E)testosterone

Question 22

A man is found to have the following symptoms: a large goiter, muscle weakness, excessively emotional and irritable disposition, extreme weight loss, a constant feeling of being too warm in normal-temperature rooms, and bulging eyes.The probable diagnosis is

A)myxedema
B)Cushing's disease
C)Conn's syndrome
D)Grave's disease
E)Addison's disease

Question 23

Plasma sodium levels are high in a patient, but his plasma potassium levels are low.As an underlying cause of this condition, you might expect to find

A)decreased aldosterone levels
B)decreased parathyroid hormone levels
C)increased aldosterone levels
D)increased parathyroid hormone levels
E)decreased insulin levels

Question 24

Mineralocorticoids

A)stimulate gluconeogenesis
B)stimulate protein degradation
C)act at the kidneys to promote sodium retention and enhance potassium elimination
D)contribute to the pubertal growth spurt
E)are important in maintaining proper plasma calcium levels

Question 25

Aldosterone

A)enhances the ability of the kidneys to eliminate excess K+
B)directly promotes H2O conservation by the kidneys
C)secretion is inhibited by angiotensin II
D)is not a steroid
E)is produced in the adrenal medulla

Question 26

Which of the following statements concerning adrenocortical hormones is incorrect?

A)Glucocorticoids are examples.
B)Some are steroids.
C)Their release is controlled directly by CRH.
D)They are secreted from the outer layer of the adrenal gland.
E)Aldosterone is an example.

Question 27

A drop in blood pressure would likely lead to

A)increased plasma aldosterone levels
B)increased vasopressin levels
C)increased levels angiotensin II
D)all of the above
E)only b and c

Question 28

Cortisol does not

A)increase the conversion of glycogen to glucose
B)stimulate gluconeogenesis in the liver
C)increase protein degradation
D)mobilize fat from adipose tissue
E)exert permissive actions

Question 29

A goiter

A)may occur with hyper- and hypothyroidism
B)refers to cancerous tumor in the thyroid gland
C)occurs only in the presence of thyroid-stimulating immunoglobulin
D)is characterized by both a and b
E)is characterized by both b and c

Question 30

Aldosterone

A)causes conservation of sodium
B)facilitates lipolysis
C)promotes gluconeogenesis
D)is regulated by ACTH
E)is secreted by the adrenal medulla

Question 31

Hypothyroidism may occur due to

A)anterior pituitary failure
B)inadequate dietary supply of iodine
C)failure of the thyroid gland itself
D)both b and c
E)all of the above

Question 32

Both ______ and _______ are produced from the same large precursor molecule, pro-opiomelanocortin.

A)aldosterone; cortisol
B)cortisol; androgen
C)ACTH; MSH
D)aldosterone; androgen
E)aldosterone; MSH

Question 33

The hormone that decreases the concentration of calcium in the blood is

A)thyroxine
B)tri-iodothyronine
C)calcitonin
D)both a and b
E)all of the above

Question 34

The most abundant and physiologically important adrenal sex hormone is

A)aldosterone
B)cortisol
C)dehydroepiandrosterone
D)estradiol
E)testosterone

Question 35

_________ is not associated with hyperthyroidism.

A)Elevated basal metabolic rate
B)Myxedema
C)Weakness
D)Excessive perspiration
E)Palpitations

Question 36

A goiter is

A)an enlarged thyroid
B)always the result of hypothyroidism
C)present only with iodine-deficient diets
D)only present when TSH levels are elevated
E)both a and d

Question 37

_________ is not a cause of hypothyroidism.

A)Lack of TRH
B)An iodine-deficient diet
C)Grave's disease
D)Lack of an enzyme necessary for one of the steps in the synthesis and release of thyroid hormone
E)Lack of TSH

Question 38

The zona glomerulosa of the adrenal cortex secretes

A)aldosterone
B)cortisol
C)androgens and estrogens
D)both b and c
E)all of the above

Question 39

Which of the following regulates aldosterone secretion?

A)ACTH
B)Renin-angiotensin system
C)Plasma K+ concentration
D)Both b and c
E)None of the above

Question 40

__________ is not associated with hyperthyroidism.

A)Poor tolerance of heat
B)Myxedema
C)Weight gain
D)Slow speech, poor memory
E)Exophthalmos

Question 41

Epinephrine does not

A)cause constriction of the respiratory airways
B)elevate the concentration of blood sugar
C)stimulate glycogenolysis in skeletal muscles
D)stimulate hepatic gluconeogenesis
E)stimulate hepatic glycogenesis

Question 42

Because aldosterone encourages the secretion of potassium ions into the urine, conditions in which excess aldosterone is secreted results in

A)hyponatremia
B)hypokalemia
C)hypotension
D)idiopathic atrophy
E)none of the above

Question 43

Epinephrine

A)is secreted by the adrenal medulla
B)is secreted along with norepinephrine
C)reinforces sympathetic nervous system activity
D)mobilizes energy reserves
E)has all of the above characteristics

Question 44

Dehydroepiandrosterone is

A)the most abundant adrenal androgen
B)responsible for the development and maintenance of the female sex drive
C)controlled by the gonadotropic hormones
D)both a and b
E)none of the above

Question 45

The major factor that promotes increased secretion of CRH is

A)low Na+ concentration in the extracellular fluid
B)stress
C)angiotensin II
D)increased blood amino acid concentration
E)increased blood glucose concentration

Question 46

Which of the following is characteristic of Conn's syndrome?

A)K+ increase in the blood
B)Na+ depletion
C)Hypertension
D)Both a and c
E)All of the above

Question 47

Catecholamines

A)are secreted by the adrenal cortex
B)reinforce the activities promoted by the parasympathetic nervous system
C)are important in the maintenance of blood pressure
D)promote glycogen storage
E)are secreted in response to hypothalamic stimulation

Question 48

The actions of glucocorticoids include

A)increased gluconeogenesis and glycogenolysis
B)increased fat mobilization
C)increased breakdown of muscle proteins
D)anti-inflammatory and immunosuppressive effects at pharmacological levels
E)all of the above

Question 49

Adrenocorticotropic hormone

A)is a tropic hormone secreted by the adrenal cortex
B)stimulates the production of androgens by the testes
C)is controlled in part by CRH from the hypothalamus
D)has characteristics a and b
E)has characteristics b and c

Question 50

Cortisol is

A)an immunosuppressive chemical
B)anti-inflammatory chemical
C)is responsible for potassium excretion
D)both a and b
E)both b and c

Question 51

Which of the following is characteristic of the adrenogenital syndrome?

A)Precocious pseudopuberty in prepubertal boys
B)Development of male-type external genitalia in female fetuses
C)Hirsutism in adult females
D)Both a and c
E)All of the above

Question 52

Which of the following hormones exhibits a marked diurnal variation in secretion?

A)aldosterone
B)cortisol
C)thyroid hormone
D)epinephrine
E)calcitonin

Question 53

Cortisol

A)is the primary mineralocorticoid
B)excess is responsible for Cushing's syndrome
C)decreases blood glucose, blood fatty acid, and blood amino acid levels
D)has characteristics a and b
E)has none of the above characteristics

Question 54

Which of the following is not characteristic of Cushing's syndrome?

A)hypernatremia
B)hyperglycemia
C)muscle weakness and fatigue
D)poor wound healing
E)"moon-face" and "buffalo hump"

Question 55

Which of the following is not seen in Addison's disease?

A)Marked Na+ loss in the urine
B)Lowered blood glucose levels
C)K+ retention
D)Protein mobilization
E)Poor response to stress

Question 56

Adrenal androgens are

A)normally secreted only in males, whereas adrenal estrogens are secreted in females
B)normally secreted in both males and females, but in insufficient amounts to cause masculinization
C)responsible for the female sex drive
D)both a and c
E)both b and c

Question 57

Diurnal variation in secretion is

A)a characteristic associated with glucocorticoids
B)is to the sleep-awake cycle
C)a result of stress
D)both a and b
E)all of the above

Question 58

An increase in plasma levels of ACTH leads to an increase in plasma _______ levels.

A)cortisol
B)glucagon
C)vasopressin
D)parathyroid hormone
E)epinephrine

Question 59

Glucocorticoids cause all of the following except

A)carbohydrate conservation
B)protein degradation
C)increased metabolic rate
D)mobilization of fats for energy
E)anti-inflammatory and immunosuppressive effects at pharmacological levels

Question 60

A student experiencing psychological and emotional stress

A)will secrete more CRH
B)will secrete more ACTH
C)will secrete more cortisol
D)may experience a greater risk of infections due to immune system suppression
E)may experience all of the above

Question 61

Secretion of _________ is stimulated by an increase in blood glucose.

A)glucagon
B)cortisol
C)growth hormone
D)insulin
E)epinephrine

Question 62

____________ does not characterize the postabsorptive state.

A)A substantial decrease in blood glucose compared to the absorptive state
B)Gluconeogenesis
C)Glucose-sparing
D)A decrease in insulin secretion
E)An increase in glucagon secretion

Question 63

Which statement about insulin is correct?

A)It promotes the insertion of additional glucose transporters in the plasma membranes of insulin-dependent cells
B)It promotes glycogenesis and inhibits glycogenolysis
C)Its secretion is increased in response to a fall in blood glucose concentration
D)Both a and b
E)Both a and c

Question 64

Which of the following hormones is not secreted in response to stress?

A)cortisol
B)epinephrine
C)insulin
D)aldosterone
E)vasopressin

Question 65

Excess circulating quantities of which of the following nutrient molecules can ultimately be stored in adipose tissue as triglycerides?

A)fatty acids
B)glucose
C)amino acids
D)Both a and b
E)All of the above

Question 66

Which statement about blood sugar level is true?

A)It must remain within normal range because the brain needs a constant supply of sugar
B)It decreases in response to glucagon secretion
C)It decreases in response to gluconeogenesis
D)Both a and b
E)None of the above

Question 67

Glycogenesis occurs in

A)the liver
B)the brain
C)working muscle
D)nonworking muscle
E)adipose tissue

Question 68

Insulin does not

A)increase GLUT-4 mobilization
B)promote glucose uptake by neural tissue
C)inhibit lipolysis
D)promote glycogenesis
E)encourage protein synthesis

Question 69

______________ during the absorptive state.

A)Glycogenolysis is occurring
B)Fats are the primary energy source
C)Glucose is the main energy source
D)Amino acid degradation is occurring
E)Glucose sparing occurs

Question 70

Catecholamines are secreted from the adrenal medulla in response to

A)increased secretion of ACTH from the anterior pituitary
B)direct sympathetic nervous system stimulation
C)decreased androgen secretion from the adrenal cortex
D)a tropic hormone secreted by the pituitary
E)stimulation by chromaffin-releasing hormone

Question 71

Which of the following does not stimulate insulin secretion?

A)Elevated blood amino acid concentration
B)Gastrointestinal hormones
C)A fast-food hamburger
D)Starvation
E)Elevated blood glucose concentration

Question 72

Glycogenesis is

A)likely to occur when the body needs extra glucose for energy
B)stimulated by glucagon
C)stimulated by insulin
D)a and b
E)a and c

Question 73

Polyuria develops from a changing osmotic effect in the kidney due to

A)glucose in the urine
B)less Na+ in the urine
C)glucosuria
D)both a and c
E)none of the above

Question 74

Identify the correct statement(s) about gluconeogenesis.

A)It is the conversion of fatty acids into glucose
B)It results in an increase in blood glucose
C)It is stimulated by insulin and GH
D)Both a and b
E)Both b and c

Question 75

Insulin

A)facilitates the transport of glucose into the glucose-dependent brain cells
B)increases blood glucose levels to ensure adequate nourishment of the brain
C)promotes fat storage in the body
D)is stimulated by a lowered blood glucose
E)has characteristics a and c

Question 76

Identify the characteristic(s) of the general adaptation syndrome.

A)Mobilization of energy reserves
B)Conservation of water and sodium
C)Increased systemic vasoconstriction
D)All of the above
E)None of the above

Question 77

Which statement about adrenomedullary hormones is incorrect?

A)Epinephrine accounts for 80% of adrenomedullary catecholamine output.
B)Epinephrine and norepinephrine are stored within chromaffin granules in the adrenomedullary cells.
C)Epinephrine and norepinephrine have about equal affinities for all the adrenergic receptor types.
D)Epinephrine is at least 10 times more potent than norepinephrine at beta 2 receptors.
E)Epinephrine exerts metabolic effects, whereas norepinephrine has limited action in this regard.

Question 78

Of the hormones secreted by the adrenal gland, those that promote an increase in the blood glucose level include

A)aldosterone
B)cortisol
C)epinephrine
D)both a and b
E)both b and c

Question 79

Select the pituitary hormone that increases the concentration of blood sugar.

A)glucagon
B)insulin
C)cortisol
D)epinephrine
E)growth hormone

Question 80

Which statement about somatostatin is incorrect?

A)It is produced by the hypothalamus.
B)It is produced by the pancreatic D cells.
C)It inhibits growth hormone secretion.
D)It inhibits digestion of nutrients and decreases nutrient absorption.
E)It is released in response to a fall in blood glucose and blood amino acids.