Toxic responses of the Endocrine System

Question 1

The inability to release hormones from the anterior pituitary would NOT affect the release of which of the following?

a. LH
b. PRL
c. ADH
d. TSH
e. ACTH

Answer 1

c. ADH

Question 2

Which of the following statements regarding pituitary hormones is TRUE?

a. The hypothalamic-hypophyseal portal system transports releasing hormones to the neurohypophysis
b. Dopamine enhances prolactin secretion from the anterior pituitary
c. Somatostatin inhibits the release of GH
d. The function of chromophobes in the anterior pituitary is unknown
e. Oxytocin and ADH are synthesized by hypothalamic nuclei.

Answer 2

d. The function of chromophobes in the anterior pituitary is unknown

Question 3

21-Hydroxylase deficiency causes masculinization of female genitals at birth by increasing androgen secretion from which region of the adrenal gland?

a. zona glomerulosa
b. zona reticularis
c. adrenal medulla
d. zona fasciculata
e. chromaffin cells

Answer 3

b. zona reticularis

Question 4

Which of the following statements regarding adrenal toxicity is TRUE?

a. The adrenal cortex and adrenal medulla are equally susceptible to fat-soluble toxins
b. Adrenal cortical cells lack the enzymes necessary to metabolize xenobiotic chemicals
c. pheochromocytomas of the adrenal medulla can cause high blood pressure and clammy skin due to increased epinephrine release
d. Xenobiotics primarily affect the hydroxylase enzymes in the zona reticularis
e. Vitamin D is an important stimulus for adrenal cortex steroid secretion.

Answer 4

c. pheochromocytomas of the adrenal medulla can cause high blood pressure and clammy skin due to increased epinephrine release

Question 5

Chemical blockage of iodine transport in the thyroid gland:

a. affects export of T3 and T4
b. prevents reduction to I2 by thyroid peroxidase
c. decreases TRH release from the hypothalamus
d. interrupts intracellular thyroid biosynthesis
e. mimics goiter

Answer 5

e. mimics goiter

Question 6

Chromaffin cells of the adrenal gland are responsible for secretion of which of the following?

a. aldosterone
b. epinephrine
c. corticosterone
d. testosterone
e. estradiol

Answer 6

b. epinephrine

Question 7

The parafollicular cells of the thyroid gland are responsible for secreting a hormone that:

a. increases blood glucose levels
b. decreases plasma sodium levels
c. increases calcium storage
d. decreases metabolic rate
e. increases bone resorption

Answer 7

c. increases calcium storage

Question 8

parathyroid adenomas resulting in increased PTH levels would be expected to cause which of the following?

a. hypocalcemia
b. hyperphosphatemia
c. increased bone formation
d. osteoporosis
e. rickets

Answer 8

d. osteoporosis

Question 9

Which of the following vitamins increases calcium and phosphorus absorption in the gut?

a. Vitamin D
b. niacin
c. vitamin A
d. vitamin B12
e. thiamine

Answer 9

a. Vitamin D

Question 10

All of the following statements regarding ovarian tumor formation are true EXCEPT:

a. Many ovarian tumors develop secondary to chronic GnRH stimulation
b. Increased sex steroid hormone secretion by the ovary is a risk factor for ovarian cancer
c. Tamoxifen has been shown to increase the incidence of ovarian tumors in mice
d. A decreased number of Graafian follicles results in decreased estrogen and progesterone secretion
e. The germinal epithelium surrounding the ovary is a common site of ovarian tumors

Answer 10

b. Increased sex steroid hormone secretion by the ovary is a risk factor for ovarian cancer