VI- Adrenal Gland Flashcards
glomerulosa produces
aldosterone
fasciculata produces
cortisol
reticularis produces
androgens
medulla produces
epinephrine and norepinephrine
cortisol function
restoring homeostasis after exposure to stressors
androgen function
DHEA and androstenedione only weak activity but converted to testosterone in peripheral tissues
-maintain pubic and axillary hair in women
-source of estradiol in post menopause
STAR protein function
aka steroidogenic acute regulatory protein
-brings cholesterol into mitochondria for processing
cholesterol side chain cleavage function
cleaves cholesterone into pregnenolone
steroid 17-alpha hydroxylase
converts pregnenlone (from mineral pathway) into 17-OH pregnonlone (a glucocorticoid) or even further to DHEA (androgen)
if deficiency then only aldosterone/mineral pathway active bc doesn’t use
21-hydroxylase function
mineral pathway: progesterone > DOC
glucocorticoid: 17-OH progesterone to 11-deoxycortisol
if deficiency then only androgen pathway active
ACTH mechanism
activates MC2R melanocortin receptors on adrenal gland = cortisol and androgen production, inc pigmentation
via cAMP so inc function/syn of STAR and inc transcription of cholesterol desmolase
cortisol effects
- inc blood amino acids thru protein degradation
- inc glucose thru gluconeogenesis
- inc blood lipids thru lipolysis
- inc blood Ca
- dec immune resp
- inc RBC
- dec inflamm
- inc appetite
- inc CO and BP thru nor/epinephrine
aldosterone effects
- dec blood K+
- inc Na retention
- inc blood vol
11beta-hydroxysteroid dehydrogenase type 2
11B-HSD II
inactivates cortisol in aldosterone target cells
-if hypercortisolism can lead to saturation so hypertension and hypokalemia
catecholamine release
from chromaffin cells triggered by stress, fear, exercise, pain
aka inc symps
