Adrenal Hormones Flashcards
what are the 3 pathways of that produce adrenal hormones? what structure do they associate with?
glucocorticoid pathway - zona fasciculata
mineralcorticoid pathways - zona glomerulosa
androgen pathway - zona reticularis
what is the zona glomerulosa?
most superficial layer of the adrenal cortex
what is the zona fasciculata?
the middle layer of the adrenal cortex
what is the zona reticularis?
the innermost layer of the adrenal cortex
what hormone(s) is the zona glomerulosa responsible for producing?
aldosterone
what hormone(s) is the zona fasciculata responsible for producing?
cortisol and androgens
what hormone(s) is the zona reticularis responsible for producing?
androgens
what is the medulla responsible for producing?
catecholamines
what is ACTH? what is its function?
adrenocorticotropin hormone
key regulator of conversion of cholesterol to pregnenolone (mineralocorticoid pathway)
what are the hormones/molecules involved in the mineralocorticoid pathway? list them in order of when they appear in the pathway.
1) cholesterol
2) pregnenolone
3) progesterone
4) 11-deoxycorticosterone
5) corticosterone
6) 18-hydroxycorticosterone
7) aldosterone
what hormones/molecules are involved in the glucocorticoid pathway? list them in order of when they appear in the pathway.
1) 17alpha-hydroxypregnenolone
2) 17alpha-hydroxyprogesterone
3) 11-deoxycortisol
4) cortisol
what hormones/molecules are involved in the androgen pathway? list them in order of when they appear in the pathway.
1) dehydroepiandrosterone (DHEA)
2) androstenedione
give two examples of the following:
glucocorticoids
mineralocorticoids
androgens
gluco - cortisol, corticosterone
mineral - aldosterone, deoxycorticosterone
andro - DHEA, androstenedione
what does cortisol bind to in circulation? how does it affect various molecules?
transcortin
effects intermediary metabolism of carbs (makes Glc available to brain by inhibiting other tissues from using it), lipids (breakdown in adipose tissue to FAs and glycerol), and proteins (stimulates breakdown to AA)
What are the anti-inflammatory actions caused by glucocorticoids?
1) inhibit local reaction to injury
2) decrease local release of degradative enzymes
3) decrease fibroblast proliferation and collagen deposition
what are the immunosuppresion actions caused by glucocorticoids?
1) inhibit IL-1 production by macrophages, decreasing T cell recruitment
2) inhibit IL-2 production by T-helper cells, decreasing T and B cell recruitment
3) induce apoptosis of T cells
What is the hypothalamus-pituitary adrenal axis feedback regulation?
1) hypothalamus releases CRH (positive release to pituitary)
2) pituitary releases ACTH (positive release to adrenal cortex)
3) Adrenal cortex releases:
a) DHEA (negative feedback on H-P-G axis)
b) Aldosterone
c) Cortisol
what is involved in the negative feedback on pituitary-adrenal axis by glucocorticoids?
Strong negative feedback on hypothalamus/pituitary
Inhibits ACTH production
Causes atrophy of anterior pituitary corticotropes (no acquired ACTH) and of adrenal cortex (lack of ACTH stimulation)
what is the function of aldosterone?
controls body fluid volume, leading to increased Na reabsorption in kidneys
what stimulates aldosterone secretion?
RAAS activation responding to low BP, low plasma Na, or high plasma K
ACTH (minor)
what is the function of DHEA in females?
1) enhancement of pubertal growth spurt
2) maintains secondary sex characteristics (pubic and axillary hair)
3) libido (sex drive)
4) conversion by aromatose to estrogen via testosterone in peripheral tissue