Mineralocorticoids Flashcards
Where are the adrenal glands located?
on top of kidneys
List the layers of the Adrenal Cortex (from superficial to deep).
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
What does the Zona glomerulosa produce?
mineralocorticoids (aldosterone)
Aldosterone production requires what process?
steroidogenesis
List the steps in the pathway for aldosterone synthesis in order (5).
Cholesterol –> Pregnenolone –> Progesterone –> Corticosterone –> Aldosterone
Aldosterone secretion is regulated by _______.
kidney (renin-angiotensin system)
What does renin do in the process of aldosterone production?
converts angiotensinogen –> angiotensin I (inactive)
What organ produces angiotensinogen?
liver
Aldosterone is secreted when there is a(n) (increased/decreased) plasma Na+ and a(n) (increased/decreased) plasma K+.
decreased
increased
What converts Angiotensin I to Angiotensin II? Where is it found?
angiotensin-converting enzyme (ACE)
lung
Angiotensin II acts on cells in the _________ to release aldosterone.
zona glomerulosa
Overall, aldosterone controls the content of ____ and ____ in the body directly, while controlling ____ directly.
Na+
K+
water
Aldosterone increases renal absorption of sodium via _______ on the basolateral membrane and _______ on the luminal side.
Na/K ATPase pump
ENAC (Na+ channels)
As secretion of potassium in the kidney increases, _____ follows via direct transport.
H+
How is K+ secreted in response to aldosterone on the renal basolateral membrane? Luminal?
Basolateral: Na/K ATPase
Luminal: passive secretion
What two parts of the body does aldosterone act on to increase absorption of Na+ and increase secretion of K+?
kidney
GI tract (intestines)
What is different about the intestinal transport of K+ secretion due to aldosterone?
passively AND actively secreted!
How is K+ actively secreted in the intestine?
Na/K ATPase, NKCC, BK channels
Term for disease with increased aldosterone.
aldosteronism
What are the two possible causes of Aldosteronism?
- adrenal cortex tumor
- overactive renin-angiotensin system
(CHF, arteriolar constriction, edema)
With Aldosteronism, _______ is increased and ______ is decreased due to negative feedback.
aldosterone
renin
In addition to tumor removal, Aldosteronism can be treated with an aldosterone antagonist, _________.
spironolactone
Term for disease with decreased aldosterone.
Addison’s Disease
Match whether each will increase or decrease during Addison’s Disease:
- Aldosterone
- ACTH
- Renin
- down
- up
- up (negative feedback)
What is the cause of Addison’s Disease?
autoimmune destruction of adrenal cortex
Addison’s Disease can cause hyperpigmentation due to elevated _____ levels.
alpha MSH
Addison’s Disease can cause hypoglycemia due to decreased _____ levels.
cortisol
What is the treatment for Addison’s Disease?
exogenous cortisol + aldosterone
Secondary Adrenal Insufficiency will have the same clinical signs as Addison’s Disease except what two things will be different?
- normal aldosterone
- no hyperpigmentation
