Adrenal glands- on top of kidneys - attached to kidneys via connective tissue capsule -cortex- stimulated by ACTH 3 layers
1. - zona glomerulosa - releases mineral corticoids - aldosterone: anti-diuretic. Retain na+ --> leads to h2o retention
(Low levels of aldosterone)-->. Hypovolemia- low blood volume-->. leads to low blood pressure
2. - zona fasciculata- glucocorticoids - cortisone, cortisol -resist stressors. -increase glucose in blood -increase protein synthesis : by releasing amino acids into blood -increase fatty acids in blood
3. -zona reticularis- secretes androgens : testosterone -in females: testosterone is responsible for muscle tone, sex drive
Pathologies of adrenal cortex
1. -Addison's disease: underproduction of corticosteroids - mineral and gluco-corticoids -symptoms: weight loss, decreased sodium levels--> high potassium, water loss from blood--> hypovolemia & low BP , fatigue, dehydration -hyposecretion: increase ACTH- looks molecularly similar to MSH- melanin stimulating hormone -excessive amounts of ACTH stimulate melanocytes to produce melanin
2. -Cushing's disease: hypersecretion of corticosteroids - increase sodium retention, edema, increase glucose levels in blood, redistribution of fat in belly or trunk, moon face (fat around face), buffalo hump (fat build up behind neck around C7)
Adrenal medulla- center of adrenal gland -produces Epinephrine and norepinephrine - mimic and enhance sympathetic nervous system and response - increase heart rate, dilate pupils, increase metabolism, shunt blood supply (more to skeletal muscle)
Lymphatic system-
Functions:- produce & maintain lymphocytes to defend against pathogens -return excess fluid that has leaked out of capillary beds to venous circulation
Lymphoid organs- thymus, spleen, tonsils,