Post on 30-Dec-2015
Adrenal Function, Testing and Disorders
Chemistry CLS 415 Didactics
Ricki Otten, MT(ASCP)SC
Part 2: Cortex Hormone Function and Regulation
Mineralcorticoids: Aldosterone
• Function/Physiologic effects• Na+ and K+ homeostasis• Regulates extracellular fluid
volume through sodium reabsorption by kidneys
• Synthesized only in the adrenal gland: zona glomerulosa
• Major control mechanism: Renin-angiotensin-aldosterone (RAA) system
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Renin: an enzyme
Produced in the juxtaglomerulosa cells of the kidney
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Angiotensin converting enzyme (ACE)
Produced in lung
Angiotensinogen: a protein substrate
Produced in liver
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Angiotensin II:
Potent vasoconstrictor
Stimulates Adrenal Cortex to produce Aldosterone
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Glucocorticoids: Cortisol
Essential for life
Major stress protector
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Glucocorticoids: Cortisol• Function/Physiologic effects
• Influences carbohydrate metabolism:• Promotes gluconeogenesis• Promotes glycogenolysis
• Stimulates protein catabolism (breakdown)• Central distribution of fat: neck, face and trunk• Anti-inflammatory actions• Immunosuppressive actions• Anti-allergic properties
Increase plasma glucose
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Glucocorticoids: Cortisol
• Diurnal variation• Under ACTH influence• Highest cortisol levels
in early am• Lowest cortisol levels
in late pm
• Synthesized in the adrenal gland
• Major control mechanism: Negative feedback control
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Hypothalamus-Pituitary-Adrenal axis
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