03 Adrenal Gland
Adrenal gland blood supply
Structures
Outer capsule, cortex, and medulla..
- Cortex: makes the corticoids
- Medulla is like a massive nerve. Also secretes dopamine
Germ Cell Layers:..
Chromaffin Cells
Neuroendocrine cells found mostly in the medulla of the adrenal glands that secretes E and NE.
Neural crest derived..
Zones:..
- mnemonic: GFR
Adrenal Gland Hormones
Zona Glomerulosa
Makes mineralcorticoids.
Desmolase
Stimulated by ACTH to make cortisol.
Aldosterone Synthase
Stimulated by Ang II to make aldosterone.
Zona Fasciculata
Makes glucocorticoids.
Zona Reticularis
Makes androgens.
17, 30 lyase double bonds at 17 position:
Mineralcorticoids
Mineral: minerals like Na/K. Corticoids: Made in the cortex
- Increase Na channels and Na/K pumps: increase Na reabsorption, K secretion on principal cell
- Increase H pump: increase H secretion on intercalated cell.
Glucocorticoids aka Cortisol
CBG
Circadian Rhythm
Circadian rhythm: Hormone is highest at morning to prepare for stress of the day.
Cortisol Effects
- Cortisol goes up in time of stress. Increases BP and necessary nutrients, and shuts down everything else..
BP Effects
Immune Effects
- Suppress because don't need immune system in stress..
- Glucocorticoids inhibit the production of IL-2, which is important for T-cell proliferation. Thus, pharmacologic doses of glucocorticoids prevent the rejection of transplanted organs.
- The induction of synthesis of lipocortin, a phospholipase A2 inhibitor, leads to the inhibition of leukotriene and prostaglandin production.
They exert these effects through several mechanisms:..
Glucose Effects
- Hyperglycemia for energy needs
- Glucocorticoids: makes glucose
Also enhances glucagon that offsets glycogen synthase effects.
- glucagon and epinephrine good for short term stress
Fat Effects
- Activates lipolysis for energy but stimulates fat deposition chronically.
Effects on muscles, skin, bones
- Negative effects because don't need any of these in stress..
Striae
Purple stretch marks in dermis that can be seen due to thinning of skin. Cortisol decreases fibroblast activity.
Corticosteroid Drugs
- oral prednisone often used for asthma, lupus, etc.
- methylprednisolone is IV form of prednisone..
Androgens
More important in females