click below
click below
Normal Size Small Size show me how
Lecture 46
Adrenal Gland
Term | Definition |
---|---|
Adrenal Medulla | inner layer of adrenal gland.similar to post-ganglion symp neuron. |
Secretions | stored in granules.epi/ne 4:1-strong peripheral effects. vit c stored and released w/ epi/ne |
Effects of Catecholamines | epi inc hr dec tpr inc co. ne inc vasoconstriction,except in heart and skeletal msucle.net effect is inc bp,and inc metabolic rate. |
Neural Control | release determined by baroreceptor activity. dec bp leads to inc epi/ne release. inc bp leads to dec epi/ne release |
Adrenal Cortex | outer layers of adrenal gland.endocrine gland. |
Secretions | released as made,not stored.all are steroid derivatives of cholesterol.mineralocortoids-cortisol et al.glucocorticoids-cortisol et al. androgens-DHEA,androstenedione. |
ACTH Effects and Control | acth from anterior pituitary when cortisol is low,stress high,on top of diurnal rhythm.atch causes inc release of all adrenal cortex steroids,except aldosterone. |
Circulation of Glucocorticoids | most bound to globulin proteins.only free form is active.activity of steroids last about one hr. |
Glucocorticoid Effects | cortisol is "stress" hormone-necessary for survival.bind to nuclear receptors to inc protein synthesis. |
Metabolism | inc protein catabolism-freezing amino acids for damage repair.inc plasma glucose. inc plasma fatty acids.glucose and fatty acids provide energy for repair. |
Permissive Actions | assists actions of glucagon and catecholamines (vasoconstrictor,bronchodilation) |
Stress | something is only a stress if acth inc. atch leads to inc cortisol release.short term leads to inc energy availability,amino acid availability,catschloamine long term stress harmful-excess protein breakdown-wasting,painful. |
Anti-Inflammatory Affects | only at high glucocortocoid levels.swelling dec histamine.also,blocks immune system-apoptosis of wbc's.must use antibiotics to prevent infection.not for routine use. |
Mineralocorticoids | aldosterone,inc na+ reab in the kidney |
Adrenal Androgens | major effects in females.no or minor effects in males. |
DHEA | sex drive and starts growth spurt at puberty in females.estrogen caps female growth spurt.no effect in males (testosterone is 100x stronger) |
Androstenedione | little effect itslef,precursor to testosterone and estradiol. |