Hypothalamic Pituitary Axis Physiology

Question 1

what lobe of the pituitary gland is directly linked to the hypothalamus

Answer 1

posterior

Question 2

what hormones are secreted by the posterior lobe of the pituitary and where are they produced

Answer 2

ADH and oxytocin, they are produced in hypothalamus and stored in pituitary until needed
(ADH also called Vasopressin)

Question 3

what is the role of ADH

Answer 3

controls thirst and urine output

Question 4

what are the roles of oxytocin

Answer 4

males = control smooth muscle in ductus deferens and prostate gland
females = control uterine smooth muscle and mammary glands

Question 5

how is the anterior lobe of the pituitary linked to the hypothalamus

Answer 5

by blood vessels, portal system between the two

Question 6

what hormones are secreted from the anterior lobe of the pituitary

Answer 6

ACTH, TSH, GH, PRL, FSH, LH, MSH

Question 7

what hormone is released from the hypothalamus to stimulate TSH release from the pituitary

Answer 7

Thyrotropin-releasing hormone(TRH)

Question 8

give examples of hormones that have a negative feedback loop with the pituitary gland

Answer 8

thyroxine, testosterone/oestrogen, cortisol

Question 9

describe the steroid hypothalamic pituitary axis

Answer 9

Hypothalamus secretes CRH, stimulates pituitary to secrete ACTH, which promotes cortisol release at adrenal gland, cortisol acts on tissues

Question 10

describe the thyroid hypothalamic pituitary axis

Answer 10

Hypothalamus secretes TRH, stimulates pituitary to secrete TSH, which promotes T4 release at thyroid, T4 acts on tissues

Question 11

describe the sex hormone hypothalamic pituitary axis

Answer 11

Hypothalamus secretes GnRH, stimulates pituitary to secrete LH/FSH, which promote release of testosterone or oestrogen, test/e2 act on tissues

Question 12

describe the growth hormone hypothalamic pituitary axis

Answer 12

Hypothalamus secretes GHRH, stimulates pituitary to release GH, GH acts on tissues

Question 13

describe the prolactin hypothalamic pituitary axis

Answer 13

Hypothalamus secretes DA(dopamine), suppresses prolactin secretion from pituitary, prolactin acts on tissues

Question 14

what is the only hypothalamic hormone axis that has suppressant effect rather than stimulating on pituitary hormone release

Answer 14

dopamine in prolactin axis

Question 15

what is the name give to the paired hormones to the pituitary hormones and give an example

Answer 15

peripheral hormones, eg TSH is pituitary and T4(thyroxine) is peripheral hormone

Question 16

what is meant by dynamic testing of hormones, as opposed to baseline testing

Answer 16

dynamic is to do a test that tries to suppress or stimulate a hormone, rather than just measuring baseline levels