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
11
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
17
GH & liver metabolism
promotes gluconeogenesis in the liver & lipolysis for cell energy ( since insulin is inhibited)
18
what amplifies GH action ?
Insulin-like growth factor 1 or IGF-1
19
GH deficiency during childhood
dwarfism
20
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
