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

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• 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

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• 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

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• 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

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• 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

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• Activates lipolysis for energy but stimulates fat deposition chronically.,

Effects on muscles, skin, bones

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• 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

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• oral prednisone often used for asthma, lupus, etc.

• methylprednisolone is IV form of prednisone..

Androgens

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More important in females