Peptide Hormones

Question 1

describe the composition of peptide hormones

Answer 1

contain amino acids or amino acid derivatives

Question 2

peptide hormones bind to ____ and work through ____

Answer 2

cell surface receptors
G reactive proteins (intercellular signalling)

Question 3

thyroxine is a ____ hormone that acts like a ____

Answer 3

peptide
steroid

Question 4

most hypothalamic-pituitary hormones are ____

Answer 4

peptide hormones

Question 5

peptide or protein hormones have cell receptors…

Answer 5

on the cell membrane

Question 6

Describe the effects of ADH on urine and plasma osmolality

Answer 6

opposite effects on urine and plasma osmolality

increases blood volume (^H2O), decreases urine volume (removes H2O)

Question 7

what causes hypernatremia?

Answer 7

high aldosterone or diet

Question 8

where is ADH produced?

Answer 8

supraoptic nuclei of hypothalamus

Question 9

where is ADH released?

Answer 9

travels down the stalk and released by posterior pituitary

Question 10

location of action of ADH

Answer 10

late distal convoluted tubule and cortical region of collecting duct

Question 11

mechanism of action of ADH

Answer 11

• ADH inserts aquaporin in membrane of DCT
• allows H2O to be reabsorbed into blood
• H2O dilutes Na in blood -> negative feeback stops release of ADH

Question 12

what effect does vasopressin have on blood vessels?

Answer 12

constricts blood vessels

Question 13

what stimulates production of oxytocin?

Answer 13

childbirth or mechanical suckling

Question 14

where is oxytocin produced?

Answer 14

paraventricular nuclei of hypothalamus

Question 15

where is oxytocin released

Answer 15

travels down stalk and released from posterior pituitary

Question 16

actions of oxytocin

Answer 16

• contracts uterus and results in childbirth
• travels to myoepithelial cells of breast causing milk let-down

Question 17

what neuroendocrine hormone plays a major role in regulation of a nonendocrine target gland?

Answer 17

prolactin

acts on breast

Question 18

what stimulates production of prolactin?

Answer 18

localized drop in dopamine in hypothalamus following pregnancy & birth

Question 19

for milk to flow from the nipple to the nursing infant ____ secretion from the posterior pituitary must occur.

Answer 19

oxytocin

Question 20

where is prolactin secreted from?

Answer 20

anterior pituitary (lactotropes)

Question 21

what is the action of prolactin?

Answer 21

causes breast to produce milk

Question 22

Which of the following is both synthesized & stored

in the hypothalamus?

A) ADH
B) Thyroid-stimulating hormone (TSH)
C) LH
D) Somatostatin
E) Somatomedin

Answer 22

somatostatin

Question 23

release of oxytocin is an example of ____ secretion

Answer 23

neuroendocrine

Question 24

what pituitary hormone has a chemical structure similar to ADH?

Answer 24

oxytocin

peptides containing 9 AAs

Question 25

how does ADH differ from oxytocin in structure?

Answer 25

2 amino acids: arginine & phenelalanine

Question 26

Increased sodium in the blood is a direct action of what hormone?

Answer 26

Aldosterone

Question 27

Increased production of aquaporin channels is mediated primarily through secretion of what hormone?

Answer 27

Vasopressin (ADH)