Hypothalamus + GH Flashcards
list the cAMP signaling pathway hormones
G-FLAT ChAMP
- GHRH (somatostatin decreases cAMP levels)
- FSH
- LH
- ACTH
- TSH
- CRH
- hCG
- ADH (V2, collecting ducts)
- MSH
- PTH
list the IP3 signaling pathway hormones
GOAT HAG
- GnRH
- Oxytocin
- ADH (V1, blood vessels)
- TRH
- Histamine
- AGII
- Gastrin
list the intracellular signaling pathway hormones
PET CAT on TV
- Progesterone
- Estrogen
- Testosterone
- Cortisol
- Aldosterone
- T3/T4
- Vitamin D
the pituitary stalk passes through ____ as it connects to the hypothalamus
sellae
the ____ artery supplies the ____ forming the primary capillary plexus
superior hypophyseal artery
median eminence
name the 4 releasing hormones and 2 inhibiting hormones
- Releasing hormones
- CRH
- GnRH
- TRH
- GHRH
- inhibiting hormones
- dopamine (prolactin)
- somatostatin
contrast magnocellular and parvocellular
- magnocellular neurons transport ocytocin (PVN) and ADH (SON) via axon transport
- The axons of the parvocellular neurosecretory neurons of the PVN project to the median eminence where their neurosecretory nerve terminals release their hormones at the primary capillary plexus of the hypophyseal portal system.
name the cells in the posterolateral area of the anterior pituitary. Why is this area important?
- gonadotrophs
- somatotrophs
Posterolateral cells are the 1st to be affected by mechanical lesions
name the cells in the anteromedial area of the AP. Why is this area important?
- corticotrophs
- thyrotrophs
This area is the most protected and resilient
where are lactotrophs located in the AP?
- they are scattered throughout the gland
all hormones except for ____ and ____ function by stimulating other endocrine glands
GH and Prolactin
name the 3 classes of AP hormones
- glycoproteins
- TSH, FSH, LH
- alpha chains identical
- B chains differ (confers biological properties)
- POMC -> ACTH
- lactogens
- GH, prolactin
- similar in structure
what are 2 ways in which GH is released
- GHRH from the hypothalamus increases GH production
- hypoglycemia -> ghrelin -> GH release from AP
describe signaling pathway of GH
Think Growth Factors
Tyrosine = GF
describe the pulsatile secretion of GH
- occurs in periodic bursts, with maximal peaks at night (usually stage 3/4 of sleep)
- sleep helps adolescents grow
describe GH actions in liver
- liver: increase glucose synthesis an increase blood glucose and increase synthesis of IGF-1 (somatomedin C)
describe GH action in adipose tissue
- adipose: increase lipid breakdown and increase free fatty acids and glycerol
- decrease glucose uptake, which increases blood glucose
describe GH action in muscle tissue
- muscle: increase amino acid uptake, which increases protein synthesis. decreases glucose uptake which increases the amount of glucose in blood
describe effects of IGF
- important for growth-promoting effects of GH
- promote linear bone growth
- increase organ size and function
- negative feedback on GH
- insufficient synthesis of IGF can result in dwarfism
- African pygmies and Laron syndrome
describe hypersecretion of GH
- before closure of epiphyseal plates = gigantism
- after closure of epiphyseal plates = acromegaly
- frontal bossing
- prominent chin
- growth of mandible (prognathism)
- enlargement of hands, feet, ears, nose
