Adrenal Cortex hormones

Question 1

Hypothalamus —> adrenal cortex

Answer 1

1. Stress stimulates PVN of hypothalamus to secrete CRF
2. Corticotrophs in anterior pituitary: POMC –> ACTH
3. ACTH targets adrenal corex (ZF and ZR)
4. Stimulates synthesis of glucocorticoids & androgens

*MAIN: cortisol

Question 2

Importance of cortisol

Answer 2

1. Increase blood glucose levels

gluconeogenesis, FA oxidation, glycogenolysis

2. Stimulate adrogen synthesis in peripheral tissues
3. Negative feedback: Long-loop
4. Can also stimulate mineralocorticoid: aldosterone receptor to synergize/mimic effect to regulate BP
5. Diurnal rhythm *peak at 8AM

Question 3

Adrenal gland components

Answer 3

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)

Question 4

21α hydroxylase deficiency (4)

Answer 4

1. build up of progesterone and 17 hydroxyprogesterone
2. shunt towards androgen synthesis
3. *no cortisol produced = no negative feedback

no aldosterone either

4. high levels of ACTH

Question 5

11ß hydroxylase deficiency

Answer 5

1. build up of 11deoxycorticosterone and 11deoxycortisol
2. shunt towards androgen synthesis
3. *no cortisol produced = no negative feedback

no aldosterone either

4. high levels of ACTH

Question 6

ACTH stimulation (8)

Answer 6

1. Decrease in cortisol –> remove adrenal gland or inhibit synthesis
2. Sleep-wake transition (wake in a fasting state, prevent hypoglycemia)
3. Stress: hypoglycemia, anesthesia, surgery, trauma, infection, pyrogen (fever)
4. Psychiatric disturbance: anxiety, depression
5. α adrenergic agonist (NE neurons project to CRH neurons), ß adrenergic antagonist
6. serotonin
7. ADH (CRH neurons also produce ADH; synergistic)
8. aminobutyric acid

Question 7

ACTH Inhibition (4)

Answer 7

1. Cortisol increase (endogenous or exogenous)
2. Enkephalins
3. Opiates
4. ACTH

(2-4: breakdown products of ACTH)

*weak short loop negative feedback

Question 8

Selective Seretonin Reuptake Inhibitors

Answer 8

1. Initially (first two weeks): stimulate CRH

serotonin neurons make synaptic contact with CRH

2. Over time (2-4 weeks): downregulate # of serotonin receptors on CRH neurons due to constant serotonin

Question 9

Low vs. High levels of CORTISOL

*TSH also shares this characteristic

Answer 9

LOW: ANABOLIC

1. protein, enzyme, hormone synthesis
2. gluconeogenesis
3. glycoven synthesis

HIGH: CATABOLIC

1. inhibition of immune cell activity
2. Breakdown, inhibit glucose uptake into tissues

Question 10

Renin-Angiotensin system

Answer 10

1. Controls ALDOSTERONE synthesis angiotensin II travels to adrenal gland