Adrenal gland
The adrenal gland is composed of two embryologically distinct tissue —the outer adrenal cortex and inner adrenal medulla.
Where are the adrenal glands located?
On each kidney
Adrenal cortex
Adrenal medulla
List the 3 adrenal cortex zones
Zona glomerulosa
Zona fasciculata-
Zona reticularis
Aldosterone
Where is it produced?
Function?
How is it regulated?
How does decreased aldosterone affect Na and K excretion?
Increases Na excretion
Decreases K excretion
How does increased aldosterone affect blood pressure, blood volume, and reabsorption?
Increases salt and water reabsorption and increases blood pressure/volume (vasoconstriction)
Describe aldosterone regulation by renin
Increased BP and blood volume suppresses renin secretion, thus suppressing aldosterone synthesis
Describe primary hyperaldosteronism
It’s an adrenal disease, such as an aldosterone-secreting adrenal adenoma or carcinoma, or adrenal cortex hyperplasia
Conn syndrome
Aldosterone-secreting adenoma
Describe secondary hyperaldosteronism
Renin-angiotensin disorder where there’s excess renin synthesis due to renin-secreting renal tumor, thus causing malignant hypertension
Primary aldosteronism “Conn’s Syndrome”
Hypoaldosteronism
Atrophy of adrenal glands
Examples of hypoaldosteronism
Consequences of hypoadrenalism
Addison’s disease signs
Cortisol physiological effects
Which two hormones have diurnal variation?
Cortisol and ACTH
Cortisol regulation
Positive feedback loop
Hypothalamus secretes CRH -> anterior pituitary secretes ACTH -> adrenal gland secretes cortisol, which goes back to stimulate the hypothalamus
How do cortisol levels affect ACTH release?
Low cortisol = more ACTH released
High cortisol = less ACTH released