145b Hypothalamic - anterior pituitary physiology Flashcards Preview

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Flashcards in 145b Hypothalamic - anterior pituitary physiology Deck (32):
1

endocrine vs nervous system - timeframe of signals

endocrine is slow, but long lasting with slower adaptation

2

posterior pituitary - aka? derived from? appearance on MRI?

neurohypophysis

neuroectoderm

bright on MRI

3

anterior pituitary - aka? derived from? what is superior to it?

adenohypophysis (Adeno = Anterior)

nasopharynx ectoderm (Rathke's pouch)

optic chiasm

4

Does the hypothalamus secret hormones into portal veins for communication with the anterior or posterior pituitary?

anterior pituitary

5

What causes the circadian rhythms secretion of hormones? what does this affect?

SCN

affect - testing hormone levels is difficult so must use suppression/stimulation tests AND continuous hormone levels actually depress downstream secretions

6

what is the only pituitary hormones that is under tonic inhibition by a hypothalamus hormone?

which hypothalamus hormone does this?

Prolactin

Dopamine

7

Prolactin - source

anterior pituitary

8

prolactin - fxn

stimulates milk production

Inhibits GnRH synthesis and release thus inhibits ovulation/spermatogenesis

(remember that the body doesn't want to ovulate while nursing so prevents another pregnancy too quickly)

9

Prolactin regulation

+ TRH and VIP (minor role)
+ estrogen (pregnancy/OCP)
+ dopamine antagonists (antipsychotics)

- dopamine (major)
- dopamine agonists (Bromocriptine; rx for prolactinoma)

10

growth hormone - source

anterior pituitary

11

growth hormone - fxn

linear growth at epiphyseal plate/muscle mass via IGF-1 (mostly from liver but also bone)

osteoclast, osteoblast differentiation

differentiation of procondrocytes

increases insulin resistance (diabetogenic) b/c its a stress hormones (wants to increase blood glucose for use by CNS)

12

Growth hormone - regulation

+ GHRH (pulsating) -- increased during exercise and sleep

- somatostatin
- glucose

13

growth hormone - source

anterior pituitary

14

growth hormone - fxn

linear growth/muscle mass via IGF-1 (mostly from liver but also bone)

increases insulin resistance (diabetogenic) b/c its a stress hormones (wants to increase blood glucose for use by CNS)

15

Growth hormone - regulation

+ GHRH (pulsating) -- increased during exercise and sleep

- somatostatin
- glucose

16

what does excess GH cause in adults? children?

acromegaly

gigantism

17

IGFBP - what are they? purpose?

IGF binding proteins

carry IGF in plasma
increase half life of IGF

18

what glycoprotein hormones share a structural subunit? which subunit?

TSH
FSH
LH
HCG

share alpha; beta give biological specifictiy
("These Fucking Loser Hormones")

19

what causes growth plate closure during puberty?

estrogen mostly

20

LH/FSH regulation

+ GnRH

-estrogen/progesterone, inhibin

21

what glycoprotein hormones share a structural subunit? which subunit?

TSH
FSH
LH
HCG

share alpha; beta give biological specifictiy

22

ACTH regulation

+ CRH, vasopressin

- cortisol (Feedback)

23

LH/FSH regulation

+ GnRH
-estrogen/progesterone, inhibin

24

What is ACTH synthesized from? what else is made?

POMC

makes MSH (tanning) too

25

ACTH regulation

+ CRH, vasopressin
- cortisol (Feedback)

26

AVP regulation

+ low volume (if it gets low enough)

+ high serum osmolarity (primary)

27

What is ACTH synethized from?

POMC

makes MSH (tanning) too

28

What is made by the neurohypophysis?

AVP

Oxytocin

29

AVP regulation

+ low volume
+ high serum osmolarity

30

AVP fxn

V 2 receptors --> aquaporin --> antidiuresis

V1 --> increased vWF --> smooth muscle contraction in intestine and skin (only at patholigcally high concentrations)

31

oxytocin regulation

+ suckiling (via afferents to brain)

+ cervical stretch receptors

32

oxytocin fxn

milk let down (myoeptihelial contraction)

uterian contractions