11 terms


Aldosterone: Function
*Stimulates kidneys to reabsorb sodium
-Water follows the sodium osmotically

-Increases both blood volume and blood pressure

*Stimulates kidneys to secrete potassium

*Stimulates kidneys to secrete hydrogen
Aldosterone: Stimulation of Release
*Adrenocorticotropic Hormone (ACTH)
-Minor role in aldosterone release
-Secreted by anterior pituitary

*Renin causes aldosterone to be produced

*Renin released in response to:
-Low blood sodium (hyponatremia)
-High blood potassium (hyperkalemia)
-Decreased blood volume/blood pressure
-Sympathetic stimulation
Aldosterone: Inhibition of Release
*Inhibition of aldosterone is manifested by inhibition of renin
-High blood sodium (hypernatremia)
-Increased blood volume/blood pressure
Aldosterone: Hypersecretion
*Primary aldosteronism
-Conn's syndrome
-Characterized by high aldosterone and low renin
-Renin levels are low due to negative feedback
-Caused by adrenal cortex tumor

*Secondary aldosteronism
-Characterized by high aldosterone and high renin
-Caused by high renin production in the kidney
Aldosterone: Hyposecretion
*Addison's Disease
-Autoimmune destruction of the adrenal cortex
Aldosterone: Where Produced
*Zona Glomerulosa—outer layer of the Adrenal Cortex of the Adrenal Gland

*A Mineralcorticoid
Conn's Syndrome
*Cause of Primary Aldosterone

*Caused by an adrenal cortex tumor

*Characterized by high aldosterone and low renin levels

*Renin levels are low due to negative feedback
-Adrenal cortex producing high levels of aldosterone has an inhibitory effect on the kidney's production of renin
Aldosterone: Hypersecretion Symptoms
*Hypernatremia (high sodium)

*Hypokalemia (low potassium)

*Alkalosis (high pH)

Aldosterone: Hyposecretion Symptoms
*Hyponatremia (low sodium)

*Hyperkalemia (high potassium)

*Acidosis (low pH)

*Hypotension (low blood pressure)
Addison's Disease
*Cause of hyposecretion of aldosterone

*Autoimmune destruction of the adrenal cortex

*Also causes hyposecretion of cortisol (which is also made in the adrenal cortex)
Renin: Stimulation of Aldosterone Release
*Renin is an enzyme released by the kidneys

*Renin converts angiotensinogen into angiotensin I

*Angiotensin I is converted to angiotensin II

*Angiotensin II stimulates the release of aldosterone