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Flashcards in Pituitary Deck (45)
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1

Hypothalamus

part of the brain that stimulates tropin releasing hormones

2

Pituitary

anterior: synthesizes stimulating hormones
posterior: stores hormones from hypothalamus for release

3

TRH

thyrotropin-releasing hormone

4

CRH

corticotropin-releasing hormone

5

GnRH

gonadotropin-releasing hormone

6

ADH or AVP

vasopressin

7

Anterior pituitary cells & secretions

lactotrophs- secrete prolactin
somatotrophs - secrete growth hormone
thyrotrophs - secrete thyroid stimulating hormone
corticotrophs - secrete ACTH
gonadotrophs - secrete LH & FSH

8

short feedback loop

hormone back to pituitary

9

long feedback loop

hormone back to hypothalamus

10

ultra short feedback

feedback between pituitary & hypothalamus

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hormone secretions

pulsatile secretions - pulse frequencies
cyclic nature or diurnal variations of hormones : nervous system regulates through signals the circadian/ diurnal variations of hormones

12

trophic hormones

affect another endocrine gland
TSH, FSH, LH, ACTH

13

direct effector hormones

act directly on peripheral tissues
growth hormone & prolactin

14

Growth hormone general

'somatotropin' takes up 1/3 of pituitary space
average pulse interval : 2-3 hours
both anabolic & catabolic hormone

15

Growth hormone peak

occurs at onset of sleep in adults

16

Growth hormone & insulin

growth hormone is an antagonist of insulin

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GH & liver metabolism

promotes gluconeogenesis in the liver & lipolysis for cell energy ( since insulin is inhibited)

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what amplifies GH action ?

Insulin-like growth factor 1 or IGF-1

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GH deficiency during childhood

dwarfism

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GH excess in childhood

gigantism

21

GH excess in adults

acromegaly: hand & feet enlargement, glucose intolerance, hypermetabolic condition, accelerated atherosclerosis

22

GH assay methods

assay for IGF1 &/or IGF-1 binding protein to assess GH levels
if liver tumor & cannot use IGF-1 --> test GHRH or L-arginine stimulation & measure GH using immunoassay

23

FSH, LH, TSH similarities

all are glycoprotein hormones
share same alpha unit
beta unit is hormone specific

24

FSH in females & males

females: follicle growth (estrogens)
males: produce sperm

25

LH in females & males

females: stims corpus luteum development (progesterone)
males: produce testosterone

26

TSH

stimulates thyroid gland to release T4 & T3

27

ACTH

preadrenocorticotropic hormone formed as active hormone
stimulates adrenal cortex
regulated by CRH & cortisol feedback to hypothalamus

28

precursor to ACTH

proopiomelancortin

29

ACTH cyclic nature

high at 8 am & low at midnight

30

Prolactin

direct effector hormone (similar to GH)
TRH & estrogens can stimulate prolactin release as well as stress, suckling, & exercise
function: effect lactation