Growth Hormone And HPA

Question 1

What are the two distinct neurocrine pathways?

Answer 1

Direct effects on distant target tissues via oxytocin and ADH from the posterior pituitary. Hormones secreted exclusively into the hypophyseal portal system affect the endocrine cells within the anterior pituitary.

Question 2

What are the 2 hormones produced in hypothalamus for release from PP?

Answer 2

Oxytocin and antidiuretic hormone.

Question 3

What are the tropic hormone of the hypothalamus and what do they affect?

Answer 3

TRH, PIH, CRH,GnRH, GHRH, GHIH. They affect the release of other hormones in the target tissue.

Question 4

What are the hormones produced by the AP, what’s their role?

Answer 4

TSH- secretion of thyroid hormone. ACTH- secretion of hormones from adrenal cortex. LH- ovulation and secretion of sex hormones. FSH- development of egg and sperm. PRL- mammary gland development and milk secretion. GH- growth and energy metabolism, stimulates IGFs.

Question 5

What factors influence growth?

Answer 5

Genetics, environment, nutrition and hormones

Question 6

Describe growth hormone.

Answer 6

Produced in the anterior pituitary, it’s stimulated by hypothalamic GHRH and is inhibited by hypothalamic somatostatin

Question 7

Why is GH essential in childhood?

Answer 7

GH stimulate long bone growth andIGFs stimulate both bone and cartilage growth.

Question 8

Use of GH in adults.

Answer 8

GH and IGFs help maintain muscle and bone mass and promote healing and tissue repository as well as modulating metabolism and bone composition.

Question 9

Describe the long loop negative feedback.

Answer 9

Inhibit release of GHRH from hypothalamus, stimulates the release of somatostatin from hypothalamus and inhibits the release of GH from anterior pituitary.

Question 10

Describe the short loop negative feedback.

Answer 10

Mediated by GH itself via stimulation of somatostatin release.