Adrenal Function Flashcards
What is the sympathetic nervous system?
Is a network of nerves that activates the body’s “fight-or-flight” response
What activates the adrenal medulla?
It is activated by the preganglionic sympathetic neurons
What is the adrenal medulla derived from?
Neuron cells called chromaffin
What are chromaffin?
Cells found in adrenal glands and in groups of nerves cells called ganglia
What does chromaffin cells do?
Make neurohormones known as catecholamines such as epinephrine
What is the main function of the adrenal medulla?
Immediate response to acute or short term stress
What are the 5 classes of steroid hormones that are produced by the adrenal cortex?
Glucocorticoids
Mineralocorticoids
Progesterone
Androgens
Estrogens
What hormone does the zona glomerulosa secrete?
A mineralocorticoid know as aldosterone
What do mineralocorticoids do?
Helps control water and electrolyte homoeostasis
What are the 8 steps in the renin-angiotensin-aldosterone system?
- Kidney detects drop in blood pressure or fluid volume
- Renin is released from the kidney
- The liver is stimulated to produce angiotensinogen
- Renin acts on angiotensinogen to form angiotensin I
- ACE released from lungs
- Ace acts on angiotensin I to form angiotensin II
- Angiotensin II stimulates vasoconstriction and stimulate the release of aldosterone from the adrenal gland
- Aldosterone acts on kidneys to stimulate reabsorption
What type of hormone is aldosterone?
Amine hormone
What are the 5 steps to how aldosterone stimulates the kidney?
- Aldosterone combines with a cytoplasmic receptor
- Hormone receptor complex initiates transcription in the nucleus
- New protein channels and pumps are made
- Aldosterone induced proteins modify existing proteins
- Results in increased Na+ reabsorption and K+ secretion
What hormones does the zona reticularis secrete?
Sex steroid hormones with weak adrenergic activity
