Adrenal Cortex hormones Flashcards
Hypothalamus —> adrenal cortex
- Stress stimulates PVN of hypothalamus to secrete CRF
- Corticotrophs in anterior pituitary: POMC –> ACTH
- ACTH targets adrenal corex (ZF and ZR)
- Stimulates synthesis of glucocorticoids & androgens
*MAIN: cortisol
Importance of cortisol
- Increase blood glucose levels
gluconeogenesis, FA oxidation, glycogenolysis
- Stimulate adrogen synthesis in peripheral tissues
- Negative feedback: Long-loop
- Can also stimulate mineralocorticoid: aldosterone receptor to synergize/mimic effect to regulate BP
- Diurnal rhythm *peak at 8AM
Adrenal gland components
Adrenal medulla: derived from ectoderm, made of nervous tissue
fast-acting response: Epinephrine and Norepinephrine
Adrenal cortex: derived from mesoderm
long-lasting response: hormonal (cortisol, DHEA, aldosterone)
21α hydroxylase deficiency (4)
- build up of progesterone and 17 hydroxyprogesterone
- shunt towards androgen synthesis
- *no cortisol produced = no negative feedback
no aldosterone either
- high levels of ACTH
11ß hydroxylase deficiency
- build up of 11deoxycorticosterone and 11deoxycortisol
- shunt towards androgen synthesis
- *no cortisol produced = no negative feedback
no aldosterone either
- high levels of ACTH
ACTH stimulation (8)
- Decrease in cortisol –> remove adrenal gland or inhibit synthesis
- Sleep-wake transition (wake in a fasting state, prevent hypoglycemia)
- Stress: hypoglycemia, anesthesia, surgery, trauma, infection, pyrogen (fever)
- Psychiatric disturbance: anxiety, depression
- α adrenergic agonist (NE neurons project to CRH neurons), ß adrenergic antagonist
- serotonin
- ADH (CRH neurons also produce ADH; synergistic)
- aminobutyric acid
ACTH Inhibition (4)
- Cortisol increase (endogenous or exogenous)
- Enkephalins
- Opiates
- ACTH
(2-4: breakdown products of ACTH)
*weak short loop negative feedback
Selective Seretonin Reuptake Inhibitors
- Initially (first two weeks): stimulate CRH
serotonin neurons make synaptic contact with CRH
- Over time (2-4 weeks): downregulate # of serotonin receptors on CRH neurons due to constant serotonin
Low vs. High levels of CORTISOL
*TSH also shares this characteristic
LOW: ANABOLIC
- protein, enzyme, hormone synthesis
- gluconeogenesis
- glycoven synthesis
HIGH: CATABOLIC
- inhibition of immune cell activity
- Breakdown, inhibit glucose uptake into tissues
Renin-Angiotensin system
- Controls ALDOSTERONE synthesis angiotensin II travels to adrenal gland