Hypothalamic Control of the Pituitary Gland

Question 1

What six hormones act on the anterior pituitary?

Answer 1

Thyroid-releasing hormone (TRH)
Corticotropin-releasing hormone (CRH)
Gonadotropin-releasing hormone (GnRH)
Growth hormone-releasing hormone (GHRH) 
Somatostatin
Prolactin-inhibiting hormone (PIH)

Question 2

List the effects of each of the hypothalamic hormones when they come into contact with the pituitary.

Answer 2

Thyroid-releasing hormone (TRH)
Stimulates release of TSH

Corticotropin-releasing hormone (CRH)
Stimulates release of ACTH

Gonadotropin-releasing hormone (GnRH)
Stimulates release of LH and FSH

Growth hormone-releasing hormone (GHRH)
Stimulates release of GH

Somatostatin
Inhibits release of GH

Prolactin-inhibiting hormone (PIH)
Stimulates decreased release of prolactin

Question 3

Describe how prolactin hormone works.

Answer 3

It binds to a cytokine receptor in the anterior pituitary that activates Janus kinase, a kinase that phosphorylates tyrosine residues.

Question 4

Prolactin ultimately activates JAK-STATs. What are those?

Answer 4

Janus kinases – signal transducers and activators of transcription

Question 5

Why are prolactin receptors called cytokine receptors?

Answer 5

Because cytokine receptors also work via JAK-STATs

Question 6

Prolactin causes what in the mammary glands?

Answer 6

Mammogenesis
Lactogenesis
Galactopoiesis

Question 7

What symptoms are indicative of hyperprolactinemia?

Answer 7

Galactorrhea
Amenorrhea
Loss of libido (because excess prolactin causes decreased release of GnRH by the hypothalamus)

Question 8

What is Sheehan’s syndrome?

Answer 8

Hemorrhagic destruction of the pituitary resulting in hypoprolactinemia

Question 9

What kind of G protein do CRH and GHRH bind to?

Answer 9

Gs

Question 10

ACTH is a derivative of ___________.

Answer 10

POMC