03 Adrenal Gland
Adrenal Gland Anatomy and Embryology
Adrenal gland blood supply
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Structures
_Outer capsule, cortex, and medulla..
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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.,
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Desmolase
_Stimulated by ACTH to make cortisol.,
Aldosterone Synthase
_Stimulated by Ang II to make aldosterone.,
Zona Fasciculata
_Makes glucocorticoids.,
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Zona Reticularis
_Makes androgens.,
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17, 30 lyase double bonds at 17 position:
Mineralcorticoids
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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
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CBG
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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
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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
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More important in females
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