1. 16
The Endocrine System

2. directly onto their target cell into the cerebrospinal fluid
A major difference between neurotransmitters and hormones is that hormones are secreted ____________.
directly onto their target cell
into the cerebrospinal fluid
into ducts
into the blood
Answer: d. into the blood

3. A major determinant of a hormone’s mechanism of action is __________.
whether the hormonal molecule is hydrophobic or hydrophilic
its size
whether it is rapid acting or slow acting
if it activates gene activity or not
Answer: a. whether the hormonal molecule is hydrophobic or hydrophilic

4. Receptors for steroid hormones are commonly located _________.
inside the target cell
on the plasma membrane of the target cell
in the blood plasma
in the extracellular fluid
Answer: a. inside the target cell

5. direct gene activation a second messenger endocytosis
Interaction with a membrane-bound receptor will transduce the hormonal message via __________.
depolarization
direct gene activation
a second messenger
endocytosis
Answer: c. a second messenger

6. immediate cessation of cell response to the hormone
Treatment of a hormone’s target cell with a phosphodiesterase inhibitor will result in ________.
immediate cessation of cell response to the hormone
prolonged activity of the cell
inability of the hormone to bind to its receptor
irreversible binding of the hormone to its receptor
Answer: b. prolonged activity of the cell

7. they are not important signal molecules.
Second messenger–activating hormones circulate in minute quantities because:
they are not important signal molecules.
small concentrations of hormone can activate many intracellular signals via amplification.
they are continuously released from the gland.
neurotransmitters also bind to hormone receptors.
Answer: b. small concentrations of hormone can activate many intracellular signals via amplification.

8. Which of the following molecules act as second messengers?
cAMP
Ca2+
Inositol triphosphate
All of the above
Answer: d. All of the above

9. the steroid hormone may direct the synthesis of the protein.
It’s possible for a steroid hormone and a protein hormone to affect the same intracellular protein because:
the steroid hormone may direct the synthesis of the protein.
the protein hormone may activate the protein.
the protein hormone may direct the synthesis of the protein.
of all of the above.
Answer: d. all of the above

10. In order for a hormone to activate a target cell, the target cell must possess _______.
a receptor
a second messenger
the hormone
a chaperone
Answer: a. a receptor

11. The most common form of endocrine malfunction is __________.
failure of the gland to produce the hormone
insensitivity of the target cell to the hormone
overproduction of the hormone by the gland
All of the above are common disorders.
Answer: d. All of the above are common disorders.

12. When the pancreas releases insulin in direct response to blood glucose, this is an example of ________ stimulation.
humoral
neural
hormonal
negative feedback
Answer: a. humoral

13. When an infant suckles at his mother’s breast, the mother’s neurohypophysis releases oxytocin. This is an example of __________ stimulation.
humoral
neural
hormonal
negative feedback
Answer: b. neural

14. When the ovaries secrete estrogen in response to the hormone GnRH, this is an example of __________ stimulation.
humoral
neural
hormonal
negative feedback
Answer: c. hormonal

15. Blood levels of hormone are kept within very narrow ranges by _________ mechanisms.
humoral
neural
hormonal
negative feedback
Answer: d. negative feedback

16. Hormones secreted into the hypophyseal portal system are delivered directly to the ________.
neurohypophysis
adenohypophysis
median eminence
infundibulum
Answer: b. adenohypophysis

17. The long bone growth-promoting effects of growth hormone are mediated by __________.
somatostatin
somatotrophs
somatomedins
insulin
Answer: c. somatomedins

18. adrenal cortex; gonads thyroid; mammary glands gonads; adrenal cortex
Secretions from the corticotrophs activate cells of the _______, while secretions from the gonadotrophs affect cells of the ________.
adrenal cortex; gonads
thyroid; mammary glands
gonads; adrenal cortex
mammary glands; gonads
Answer: a. adrenal cortex; gonads

19. hyposecretion of oxytocin hypersecretion of oxytocin
A patient is displaying high volumes of urine output and severe dehydration. The most likely cause is _________.
hyposecretion of oxytocin
hypersecretion of oxytocin
hyposecretion of ADH
hypersecretion of ADH
Answer: c. hyposecretion of ADH

20. Common secretion(s) of the thyroid gland is (are) _________.
calcitonin
triiodothyronine
thyroxine
all of the above
Answer: d. all of the above

21. hypersecretion of calcitonin
A patient is losing weight rapidly, sweating profusely, and is always anxious. The patient may be suffering from _______.
hypothyroidism
cretinism
hyperthyroidism
hypersecretion of calcitonin
Answer: c. hyperthyroidism

22. Occasionally, a female patient will experience hirsutism, or excessive facial hair growth. However, blood tests reveal that her levels of testosterone are normal for a female. Another cause could be hypersecretion of:
catecholamines.
mineralocorticoids.
glucocorticoids.
gonadocorticoids.
Answer: d. gonadocorticoids.

23. Thyroid hormones; calmodulin Calcitonin; PTH
Two hormones govern calcium regulation. ________ acts to elevate blood calcium levels, whereas ________ lowers blood calcium levels.
PTH; calcitonin
Thyroid hormones; calmodulin
Calcitonin; PTH
Calcitonin; thyroid hormone
Answer: a. PTH; calcitonin

24. __________ is the adrenal hormone responsible for maintaining appropriate blood sodium levels.
Cortisol
DHEA
Aldosterone
Epinephrine
Answer: c. Aldosterone

25. _________ trigger(s) secretion of aldosterone.
Increased K+
Angiotensin II
ANP
Both a and b
Answer: d. Both a and b

26. During times of stress, elevated levels of _______ often occur, which explains why we get a cold during final exam time.
cortisol
aldosterone
ACTH
androgens
Answer: a. cortisol

27. Along with the sympathetic nervous system, the _________ is the other primary mediator of acute stress.
adrenal medulla
adrenal cortex
zona glomerulosa
zona reticularis
Answer: a. adrenal medulla

28. The secretion of ________ helps regulate our circadian rhythms.
estrogen
testosterone
thyroid hormones
melatonin
Answer: d. melatonin

29. The thymus secretes the hormone(s) ______________.
thymopoietin
thymosin
thymic factor
all of the above
Answer: d. all of the above

30. Which of the following structures produces a hormone responsible for stimulating red blood cell production?
Stomach
Heart
Kidney
Skin
Answer: c. Kidney

31. Which of the following structures produces a precursor to hormonal vitamin D, important for Ca2+ regulation?
Stomach
Heart
Kidney
Skin
Answer: d. Skin