adrenal function, testing and disorders chemistry cls 415 didactics ricki otten, mt(ascp)sc part 2:...

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

2

Renin: an enzyme

Produced in the juxtaglomerulosa cells of the kidney

3

Angiotensin converting enzyme (ACE)

Produced in lung

Angiotensinogen: a protein substrate

Produced in liver

4

Angiotensin II:

Potent vasoconstrictor

Stimulates Adrenal Cortex to produce Aldosterone

5

6

2

1

7

2

1

8

2

1

9

2

1

Glucocorticoids: Cortisol

Essential for life

Major stress protector

10

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

11

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

12

Hypothalamus-Pituitary-Adrenal axis

13