Hypothalamic and Pituitary Function Flashcards
Open-loop negative feedback refers to the phenomenon of
a. Negative feedback with a modifiable set point
b. Blood flow in the hypothalamic–hypophyseal portal system
c. Blood flow to the pituitary via dural-penetrating vessels
d. Negative feedback involving an unvarying, fixed set point
a. Negative feedback with a modifiable set point
The specific feedback effector for FSH is
a. Inhibin
b. Activin
c. Progesterone
d. Estradiol
a. Inhibin
Which anterior pituitary hormone lacks a stimulatory hypophysiotropic hormone?
a. Prolactin
b. Growth hormone
c. Vasopressin
d. ACTH
a. Prolactin
The definitive suppression test to prove autonomous production of growth hormone is
a. Oral glucose loading
b. Somatostatin infusion
c. Estrogen priming
d. Dexamethasone suppression
a. Oral glucose loading
Which of the following is influenced by growth hormone?
a. All of these
b. IGF-I
c. IGFBP-III
d. Lipolysis
a. All of these
What statement concerning vasopressin secretion is NOT true?
a. All of these.
b. Vasopressin secretion is closely tied to plasma osmolality.
c. Changes in blood volume also alter vasopressin secretion.
d. A reduction in effective blood volume overrides the effects of plasma osmolality in regulating vasopressin secretion.
a. All of these.
What are the long-term sequelae of untreated or partially treated acromegaly?
a. An increased risk of colon and lung cancer
b. A reduced risk of heart disease
c. Enhanced longevity
d. Increased muscle strength
a. An increased risk of colon and lung cancer
TRH stimulates the secretion of
a. Prolactin and TSH
b. Prolactin
c. Growth hormone
d. TSH
a. Prolactin and TSH
Estrogen influences the secretion of which of the following hormones?
a. All of these
b. Growth hormone
c. Prolactin
d. Luteinizing hormone
a. All of these
What is the difference between a tropic hormone and a direct effector hormone?
a. Tropic and direct effector hormones are both similar in that both act directly on peripheral tissue.
b. Tropic and direct effector hormones are both similar in that both act directly on another endocrine gland.
c. Tropic hormones act on peripheral tissue, while direct effector hormones act on endocrine glands.
d. Tropic hormones act on endocrine glands, while direct effector hormones act on peripheral tissues.
d. Tropic hormones act on endocrine glands, while direct effector hormones act on peripheral tissues.
A deficiency in vasopressin can lead to which of the following?
a. Euvolemic hypokalemia
b. Euvolemic hyponatremia
c. Diabetes insipidus
d. Primary hypothyroidism
c. Diabetes insipidus
Which of the following hormones stimulate prolactin secretion?
a. Dopamine
b. GnRH
c. TRH
d. TSH
c. TRH
Which hormone most directly stimulates testosterone secretion?
a. LH
b. FSH
c. GnRH
d. TRH
a. LH
Which of the following is NOT likely to be present in an “atypical pituitary tumor” as defined by the World Health Organization (WHO)?
a. Invasion into surrounding structures such as the cavernous sinus
b. MIB-1 proliferative index greater than 3%
c. Excessive p53 immunoreactivity
d. Decreased mitotic activity
d. Decreased mitotic activity
Concerning secretion of growth hormone, which of the following is NOT true?
a. Secretion is stimulated by GHRH.
b. Secretion is pulsatile, occurring usually 2 to 3 times daily.
c. The most reproducible surge is at the onset of sleep.
d. It is secreted from somatotrophs that constitute over one-third of normal pituitary weight
b. Secretion is pulsatile, occurring usually 2 to 3 times daily.