Pathophysiology: Chapter 21: Mechanisms of Hormonal Regulation

Question 1

What imbalance lessens the rate of secretion of parathyroid hormone (PTH)?

a. Increased serum calcium levels
b. Decreased serum magnesium levels
c. Decreased levels of thyroid-stimulating hormone
d. Increased levels of thyroid-stimulating hormone

Answer 1

ANS: A
The overall effect of parathyroid hormone (PTH)is to increase serum calcium and to
decrease serum phosphate concentration. The other presented imbalances will not affect
PTH in the described fashion.

Question 2

Regulation of the release of catecholamines from the adrenal medulla is an example of
which type of regulation?
a. Negative feedback c. Neural
b. Positive feedback d. Physiologic

Answer 2

ANS: C
The release of hormones occurs either in response to an alteration in the cellular
environment or in the process of maintaining a regulated level of certain hormones or
certain substances. Several different mechanisms, one of which is neural control (e.g.,
stress-induced release of catecholamines from the adrenal medulla), regulate the release of
hormones. The remaining options do not accurately describe the example given.

Question 3

How does a faulty negative-feedback mechanism result in a hormonal imbalance?

a. Hormones are not synthesized in response to cellular and tissue activities.
b. Decreased hormonal secretion is a response to rising hormone levels.
c. Too little hormone production is initiated.
d. Excessive hormone production results from a failure to turn off the system.

Answer 3

ANS: D
Negative-feedback systems are important in maintaining hormones within physiologic
ranges. The lack of negative-feedback inhibition on hormonal release often results in
pathologic conditions. Excessive hormone production, which is the result of the failure to
turn off the system, can cause various hormonal imbalances and related conditions. The
correct option is the only accurate description of this hormonal function.

Question 4

Which substance is a water-soluble protein hormone?

a. Thyroxine c. Follicle-stimulating hormone
b. Aldosterone d. Insulin

Answer 4

ANS: D
Peptide or protein hormones, such as insulin, pituitary, hypothalamic, and parathyroid, are
water soluble and circulate in free (unbound) forms. All the remaining options are
fat-soluble hormones.

Question 5

Which of the following is a lipid-soluble hormone?

a. Cortisol c. Epinephrine
b. Oxytocin d. Growth hormone

Answer 5

ANS: A
Cortisol and adrenal androgens are lipid-soluble hormones and are primarily bound to a
carrier or transport protein in circulation. The other options are water-soluble hormones.

Question 6

Most protein hormones are transported in the bloodstream and are:

a. Bound to a lipid-soluble carrier
b. Free in an unbound, water-soluble form
c. Bound to a water soluble–binding protein
d. Free because of their lipid-soluble chemistry

Answer 6

ANS: B
Peptide or protein hormones, such as insulin, pituitary, hypothalamic, and parathyroid, are
water soluble and circulate in free (unbound) forms. The other options are not true
statements related to the transport of protein hormones.

Question 7

When insulin binds its receptors on muscle cells, an increase in glucose uptake by the
muscle cells is the result. This is an example of what type of effect by a hormone?
a. Pharmacologic c. Synergistic
b. Permissive d. Direct

Answer 7

ANS: D
Direct effects are the obvious changes in cell function that specifically result from the
stimulation by a particular hormone. The other options are not used to identify the
described effect.

Question 8

Thyroid-stimulating hormone (TSH) is released to stimulate thyroid hormone (TH) and is
inhibited when plasma levels of TH are adequate. This is an example of:
a. Positive feedback c. Neural regulation
b. Negative feedback d. Physiologic regulation

Answer 8

ANS: B
Feedback systems provide precise monitoring and control of the cellular environment.
Negative feedback occurs because the changing chemical, neural, or endocrine response to
a stimulus negates the initiating change that triggered the release of the hormone.
Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates TSH secretion
from the anterior pituitary. Secretion of TSH stimulates the synthesis and secretion of THs.
Increasing levels of T4 and triiodothyronine (T3) then generate negative feedback on the
pituitary and hypothalamus to inhibit TRH and TSH synthesis. The described example is
not accurately identified by any of the other options.

Question 9

Lipid-soluble hormone receptors are located:

a. Inside the plasma membrane in the cytoplasm
b. On the outer surface of the plasma membrane
c. Inside the mitochondria
d. On the inner surface of the plasma membrane

Answer 9

ANS: A
Lipid-soluble hormone receptors are located inside the plasma membrane and easily
diffuse across the plasma membrane to bind to either cytosolic or nuclear receptors. The
other options are not true statements.

Question 10

Which second messenger is stimulated by epinephrine binding to a -adrenergic receptor?

a. Calcium
b. Inositol triphosphate (IP3)
c. Diacylglycerol (DAG)
d. Cyclic adenosine monophosphate (cAMP)

Answer 10

ANS: D
Second-messenger molecules are the initial link between the first signal (hormone) and the
inside of the cell (see Table 21-3). For example, the binding of epinephrine to a 
adrenergic–receptor subtype activates (through a stimulatory G protein) the enzyme,
adenylyl cyclase. Adenylyl cyclase catalyzes the conversion of adenosine triphosphate
(ATP) to the second messenger, 3’, and 5’-cAMP. The remaining messengers are not
stimulated by epinephrine to bind as described.

Question 11

Which hormone does the second messenger calcium (Ca++) bind to activate phospholipase
C through a G protein?
a. Angiotensin II c. Estrogen
b. Thyroxine d. Testosterone

Answer 11

ANS: A
Ca++ is considered an important second messenger that facilitates the binding of a hormone
(e.g., norepinephrine, angiotensin II) to a surface receptor, activating the enzyme
phospholipase C through a G protein inside the plasma membrane. None of the other
options acts on its target cell via a second messenger.

Question 12

The control of calcium in cells is important because it:

a. Is controlled by the calcium negative-feedback loop.
b. Is continuously synthesized.
c. Acts as a second messenger.
d. Carries lipid-soluble hormones in the bloodstream.

Answer 12

ANS: C
In addition to being an important ion that participates in a multitude of cellular actions,
Ca++ is considered an important second messenger. The other options are not true
statements related to the control of calcium within the cells.

Question 13

The portion of the pituitary that secretes oxytocin is:

a. Posterior c. Anterior
b. Inferior d. Superior

Answer 13

ANS: A

Only the posterior pituitary secretes oxytocin.

Question 14

Antidiuretic hormone acts to cause vasoconstriction when:

a. Urine output is less than 20 ml/hr.
b. Serum osmolality is increased.
c. Osmotic and oncotic pressures are increased.
d. Vasopressin is pharmacologically administered.

Answer 14

ANS: D
ADH was originally named vasopressin because, in extremely high doses, it causes
vasoconstriction and a resulting increase in arterial blood pressure. However, significant
vasoconstriction may only be achieved pharmacologically. Antidiuretic hormone induced
vasoconstriction is not a result of the other options.

Question 15

What is the target tissue for prolactin-releasing factor?

a. Hypothalamus c. Mammary glands
b. Anterior pituitary d. Posterior pituitary

Answer 15

ANS: B
Prolactin-releasing factor targets the anterior pituitary gland to stimulate the secretion of
prolactin. The other remaining options are incorrect.

Question 16

Where is antidiuretic hormone (ADH) synthesized, and where does it act?

a. Hypothalamus; renal tubular cells
b. Renal tubules; renal collecting ducts
c. Anterior pituitary; posterior pituitary
d. Posterior pituitary; loop of Henle

Answer 16

ANS: A
Once synthesized in the hypothalamus, ADH acts on the vasopressin 2 (V2) receptors of
the renal duct cells to increase their permeability. This information helps eliminate the
other options.

Question 17

Where is oxytocin synthesized?

a. Hypothalamus
b. Paraventricular nuclei
c. Anterior pituitary
d. Posterior pituitary

Answer 17

ANS: D
ADH and oxytocin are synthesized in hypothalamic neurons but are stored and secreted by
the posterior pituitary. The other options do not synthesize oxytocin.

Question 18

The releasing hormones that are made in the hypothalamus travel to the anterior pituitary
via the:
a. Vessels of the zona fasciculata
b. Infundibular stem
c. Hypophyseal stalk
d. Portal hypophyseal blood vessels

Answer 18

ANS: D
Releasing and inhibitory hormones are synthesized in the hypothalamus and are secreted
into the portal blood vessels through which they travel to the anterior pituitary hormones.
The releasing hormones do not enter the anterior pituitary gland via any of the other
options.

Question 19

Which mineral is needed for thyroid-stimulating hormone (TSH) to stimulate the secretion
of thyroid hormone (TH)?
a. Iron 
b. Zinc 
c. Iodide
d. Copper

Answer 19

ANS: C
TSH, which is synthesized and stored in the anterior pituitary, stimulates secretion of TH
by activating intracellular processes, including the uptake of iodine necessary for the
synthesis of TH. This supports the elimination of the other options.

Question 20

Which hormone triggers uterine contractions?

a. Thyroxine c. Growth hormone
b. Oxytocin d. Insulin

Answer 20

ANS: B
Oxytocin is responsible for the contraction of the uterus and milk ejection in lactating
women and may affect sperm motility in men. The remaining options are not capable of
triggering uterine contractions.

Question 21

What effect does hyperphosphatemia have on other electrolytes?

a. Increases serum calcium.
b. Decreases serum calcium.
c. Decreases serum magnesium.
d. Increases serum magnesium.

Answer 21

ANS: B

Hyperphosphatemia leads to hypocalcemia; the other options are incorrect.

Question 22

Insulin transports which electrolyte in the cell?

a. Potassium c. Sodium
b. Calcium d. Phosphorus

Answer 22

ANS: A
Insulin facilitates the intracellular transport of potassium, phosphate, and magnesium.
Insulin does not facilitate the transport of the other electrolytes.

Question 23

A person who has experienced physiologic stresses will have increased levels of which
hormone?
a. Adrenocorticotropic hormone 
b. Thyroid hormone
c. Somatostatin 
d. Alpha endorphin

Answer 23

ANS: A
Stress has been shown to increase adrenocorticotropic hormone secretion. The other
options are not increased with stress.

Question 24

What is the action of calcitonin?

a. Increases metabolism.
b. Decreases metabolism.
c. Increases serum calcium.
d. Decreases serum calcium.

Answer 24

ANS: D
Calcitonin, also called thyrocalcitonin, acts to lower serum calcium levels by inhibiting
bone-resorbing osteoclasts, making the other options incorrect.

Question 25

Which hormone is involved in the regulation of serum calcium levels?

a. Parathyroid hormone (PTH)
b. Thyroxine (T4)
c. Adrenocorticotropic hormone (ACTH)
d. Triiodothyronine (T3)

Answer 25

ANS: A
The parathyroid glands produce PTH, a regulator of serum calcium; therefore the other
options are incorrect.

Question 26

Which hormone inhibits the secretion of growth hormone (GH)?

a. Somatostatin
b. Thyroxine
c. Thyroid-stimulating hormone
d. Calcitonin

Answer 26

ANS: C
Two hormones from the hypothalamus control GH secretion: (1) GH-releasing hormone
(GHRH), which increases GH secretion; and (2) somatostatin, which inhibits it. The other
options would not produce the necessary effect.

Question 27

Target cells for parathyroid hormone are located in the:

a. Tubules of nephrons
b. Thyroid gland
c. Glomeruli of nephrons
d. Smooth and skeletal muscles

Answer 27

ANS: A
Parathyroid hormone acts on its plasma membrane receptor only in the distal and proximal
tubules of the kidney’s nephron.

Question 28

Which compound or hormone is secreted by the adrenal medulla?

a. Cortisol
b. Epinephrine
c. Androgens
d. Aldosterone

Answer 28

ANS: B
Of the available options, the catecholamine epinephrine (adrenaline) is the only major
product secreted.

Question 29

The secretion of adrenocorticotropic-stimulating hormone (ACTH) will result in the
increased level of which hormone?
a. Thyroxine 
b. Insulin
c. Cortisol. 
d. Antidiuretic hormone

Answer 29

ANS: C
Psychologic and physiologic stress (e.g., hypoxia, hypoglycemia, hyperthermia, exercise)
increases ACTH secretion, leading to increased cortisol levels. Only cortisol describes the
appropriate feedback loop.

Question 30

Which human physiologic system is believed to be an integral factor in unhealthy aging?

a. Cardiac
b. Endocrine
c. Central nervous
d. Urinary

Answer 30

ANS: B
Because the endocrine system is integral to health, changes in endocrine function have
been used as biomarkers for unhealthy aging. The other systems, although contributing to
the unhealthy aging, are not as integral.

Question 31

What are the effects of aging on pancreatic cells?

a. Pancreatic cells are replaced by fat cells.
b. Increased insulin production is typical.
c. Beta cell production increases.
d. No appreciable change occurs on pancreatic cells.

Answer 31

ANS: A
With aging, the pancreatic cells are increasingly replaced with fat tissue. Dysfunction of
the pancreas with decreased insulin secretion of the beta cells, insulin receptors, and
insulin resistance have all been documented.

Question 32

Aldosterone directly increases the reabsorption of:

a. Magnesium
b. Calcium
c. Sodium
d. Water

Answer 32

ANS: C
In the kidney, aldosterone primarily acts on the epithelial cells of the nephron-collecting
duct to increase sodium ion reabsorption. This action cannot be said of the other options.

Question 33

Which is an expected hormonal change in an older patient?

a. Thyroid-stimulating hormone secretion below normal
b. Triiodothyronine level below normal
c. Cortisol level below normal
d. Adrenocorticotropic hormone level above normal

Answer 33

ANS: A
Aging causes overall thyroid-stimulating hormone secretion to diminish but does not bring
about the other changes.

Question 34

What are actions of glucocorticoids? (Select all that apply.)

a. Decreasing muscle cell reuptake of glucose
b. Fat storage
c. Decreased blood glucose
d. Carbohydrate metabolism
e. Liver gluconeogenesis

Answer 34

ANS: A, D, E
The term glucocorticoid refers to those steroidal hormones that have direct effects on
carbohydrate metabolism. These hormones increase blood glucose concentration by
promoting gluconeogenesis in the liver and by decreasing uptake of glucose into muscle
cells, adipose cells, and lymphatic cells. Glucocorticoids are not capable of fat storage.

Question 35

Calcitonin is from which endocrine gland?

Answer 35

ANS: Thyroid

Question 36

Cortisol is from which endocrine gland?

Answer 36

ANS: Adrenal Cortex

Question 37

Oxytocin is from which endocrine gland?

Answer 37

ANS: Posterior Pitutary

Question 38

Glycoproteins are from which endocrine gland?

Answer 38

ANS: Anterior Pitutary

Question 39

Epinephrine is from which endocrine gland?

Answer 39

ANS: Adrenal Medulla