Endocrinology: Adrenal Glands Flashcards
the ____ is important in pregnancy, lies between the ___ and ____ in the fetus. Very thick and rich source of ______, where it is converted to estrogen in the _____
fetal adrenal zone
cortex and medulla
androgens
placenta
glucocorticoids are released from the _____ layer of the cortex
both the zona fasciculata and zona reticularis
mineralocorticoids are released from the ______
zona glomerulosa
sex hormones/androgens are released from the ____
zona reticularis and zona fasciculata
______ is a group of modified post-ganglionic sympathetic nerve cells
adrenal medulla
adrenal medulla is composed of ____ cells
chromaffin cells (nerve cells without axons)
the adrenal medulla releases ____ and ____
80% EPI and 20% NE
EPI and NE are derived from ______
tyrosine
EPI/NE have similar effects at _____ receptors
beta1
EPI more selective at _____
beta2
5 big effects of EPI
1) mediate the body responses to stress (fight or flight)
2) increase cardiac output, blood flow (selective vasodilation/vasoconstriction)
3) stimulates glycogen/fat breakdown = fuels
4) stimulate insulin/glucagon both
5) enhances airway/respiration and CNS alertness
EPI adjusts blood flow: selective vasodilation in _____ via ____ receptor, and vasoconstriction in ___, ____, and ___
muscle —- beta2
gut, skin, and kidney —- alpha 1 and alpha 2 (digestive organs)
NE more important in ______ situations
non-emergency (adrenal source during emergency, autonomic system source during non-emergency)
______ is an adrenomedullary dysfunction in which there is an overproduction of catecholamines (mainly NE). Describe the pathophysiology. What is a specific diagnostic test?
- pheochromocytoma
- chromaffin cells from the neural crest migrate during embryogenesis all over the body to form nerve tissues, and can form pockets of chromaffin cells acting like small adrenal medulla glands all over body.
- measuring the NE/EPI levels
_____ is symptom that has the most frequent occurrence in pheochromocytoma. Why?
HTN
NE is secreted more then EPI, thus more vasoconstriction effects that leads to HTN.
draw out the adrenal steroid biosynthesis - aldosterone
CHL — PREG —- PROG — 11 - deoxycorticosterone —- corticosterone —- aldosterone
draw out the adrenal steroid biosynthesis - cortisol
CHL — PREG —17-hydroxypreg —- 17-Hydroxyprogesterone —- deoxycortisol —– cortisol
draw out the adrenal steroid biosynthesis - testosterone and estradiol
CHL — PREG — 17 - HYDROXYPREG —- DEHYDROEPIANDROSTERONE (DHEA) —- ANDROSTENEDIONE —- TESTOSTERONE —– ESTRADIOL
____ is main compound in non-pregnant women
estradiol
____ is main compound in pregnant women
estriol
important enzyme that cleaves off side chain from testosterone to make estrogen
aromatase
____ is the rate limiting step in adrenal steroid biosynthesis
CHL —> Pregnenalone
what is the major control mechanism for each zone of the adrenal cortex?
Z. glomerulosa —> renin-angiotensin system
Z. fasciculata –> ACTH
Z. reticular –> ACTH
Theoretically: how could Z. fasciculata and Z. reticularis grow larger than Z. glomerulosa?
ACTH is trophic, so could influence growth of fasciculata and reticularis; whereas angiotensin is NOT trophic
