module 7 endocrine organs/glands

Question 1

hypothalamic-pituitary system

Answer 1

pituitary gland located within the sella turcica of the sphenoid bone and is connected to the hypothalamus by a stalk-like infundibulum.

Question 2

hypothalamus and posterior pituitary

Answer 2

neurons in hypothalamus send axons down pituitary stalk terminating in posterior pituitary.
- release of hormones occurs when action potential in hypothalamus neurons travel down and trigger excytosis of hormone from terminals in pituitary

Question 3

hypothalamus and anterior pituitary

Answer 3

hypothalamus secrets releasing or inhibiting hormones from hypothalmic neurons through portal system to anterior pituitary (blood)

Question 4

anterior pituitary has 5 endocrine cell types

Answer 4

corticotrope
thyrotrope
gonadotrope
somatotrope
lactotrope

Question 5

ADH stimulus and target

Answer 5

regulator: osmolality of plasma detected by osmoreceptor neurons in hypothalamus- has a set point
- also stimulated by baroreceptors in response to hypovolemia
target: distal renal tubules

Question 6

ADH causes

Answer 6

aquaporins to move from cytoplasm to cell membrane of apical tubular epithelial cells

• allow free diffusion of water from tubular fluid into cell
• – water flows out of membrane into interstitium -> vasculature

Question 7

oxytocin stimulus and target

Answer 7

stimulated by: 
- sexual arousal
- orgasm, intercourse
- stretching of cervix
- stimulation of nipples 
primary target: breast, uterus

Question 8

oxytocin causes

Answer 8

uterine contractions (labor, intercourse)
eject milk during breast feeding

Question 9

Thyroid

Answer 9

composed of microscopic follices surrounding colloid
- follicular cells perform functions to make and secrete hormones
parafollicular cells: C cells: secrete calcitonin

Question 10

regulation of thyroid hormone

Answer 10

TRH: thyrotropin-releasing hormone (hypothalmus)
TSH: thyroid stimulating hormone (anterior pituitary)

Question 11

thyroid hormones

Answer 11

T4 and T3

bound to thyroxine binding globulin, thyroxin binding prealbumin, or albumin

Question 12

thyroid hormone function

Answer 12

growth and maturation
cell metabolism
heat production
oxygen consumption

Question 13

adrenal glands

Answer 13

located atop the kidneys
composed of
- inner medulla
- outer cortex

Question 14

adrenal cortex 3 zona

Answer 14

zona glomerulosa (outer most)
zona fasciculata (middle)
zona reticularis (inner most, right around medulla)

Question 15

zona glomerulosa

Answer 15

produces mineralcorticoids

• aldosterone
• -Renin-angiotensin system

Question 16

zona fasciculata

Answer 16

produces glucocorticoids

• cortisol
• -somatostatin: inhibitory, negative feedback

Question 17

zona reticularis

Answer 17

produces androgens

- sex steroids

Question 18

Adrenal medulla

Answer 18

SNS and PNS nervous system innervation

Question 19

Steriod diffusion pathways

Answer 19

classical: binds with cytoplasmic receptor which moves into nucleus
other: binds to receptors already in nucleus or to cell-membrane associated receptors
- more rapid change in cell function

Question 20

glucocorticoids

Answer 20

zona fasciculata of adrenal cortex; cortisol
named for primary effect on glucose
- oppose effects of insulin and raise BG
promote lipolysis and increase blood cholesterol
protect against damaging effects of stress
regulate inflammatory and immune response

Question 21

mineralcorticoids

Answer 21

zona glomerulosa of adrenal cortex: aldosterone
maintain Na and H2O balance
- Na retention, K excretion

Question 22

Parathyroid glands

Answer 22

PTH: parathyroid homone
- regulator of serum calcium
- antagonist of calcitonin
decreased serum Ca -> increased PTH secretion -> acts on bone, kidney, and gut to absorb Ca

Question 23

hormone specificity is conveyed by

Answer 23

beta-subunit and the resulting three dimensional protein structure