adrenal Flashcards
adrenal medulla leads to:
Catecholamine release?/
adrenal medulla leads to:
Catecholamine release
Epinephrine 80% (main catecholamine released by the adrenal medulla)
Norepinephrine 20%
chatecholamine will function to
Stimulates the “fight or fight” reaction
Increased plasma glucose levels
Increased cardiovascular function
Increased metabolic function
Decreased gastrointestinal and genitourinary function
Two primary enzymes are involved in the degradation of catecholamines:
Monoamine oxidase (MAO) Catechol-O-methyltransferase (COMT).
Norepinephrine is degraded by MAO and COMT after ?
Norepinephrine is degraded by MAO and COMT after uptake into the presynaptic terminal.
]the predominant fate of adrenal catecholamines is ?
However, the predominant fate of adrenal catecholamines is methylation by COMT in nonneuronal tissues such as the liver and kidney.
each section makes..
zona glomerulosa -
fasciculata -
reticularis-
aldosterone
cortisol
DHEA-dehydroepiandosterone
First two reactions in the steroidogenic pathway:
First two reactions in the steroidogenic pathway:
- Conversion of cholesterol to pregnenolone
- Conversion of pregnenolone (P5) to progesterone (P4) in zona fasciculata cells.
Adrenal Cortex:zona fasciculata: Steroid Hormone Production 1 pathway
LDL (or any other lipopotein that caries cholesterol will attach to it’s receptor
- Lysosomal acid hydrolase will convert cholesterol ester to free ester
- free ester will go into mito. with help of StAR
- FC will become pregnenolone(p5) with help of CPY11A1
- P5 will become progestrerone (P4) By 3beta HSD
StAR
steroid acute regulatory protein
CPY11A1
Cleavage :FC to P5
3 Beta HSD
Hydroxysteroid dehydrogenase : p5 to p4
explain metabolic action of normal stress vs chronic stress
normal: increase cortisol, and decrease in insulin/glucagon ratio leads to increase in epi and nore epi …. will cause increase in gluconeogenesis and protein synthesis and fatty acid release
chronic : increase in cortisol and increase and insulin/glucagon ratio leads to DECREASE in epi and norepi…. will cause increase in appetite and glycogen synthesis and decrease in lipid release
cotisol role in metabolic effects
Enhances gluconeogenesis, lipolysis & ketogenesis
cortisol role in cardiovascular effects
Cardiovascular
Maintain output; increase arteriole tone
Decrease endothelial permeability
cortisol role in cns effects
CNS Effects
Alters circadian rhythms & calcium balance
Affects memory, learning & mood