Card Set Information
What is the primary mineralocorticoid, its function, and where is it secreted from?
Aldosterone - increases Na reabsorption at nephron, sweat, stool, saliva
What are the controls of aldosterone secretion?
Systems for fluid/electrolyte homeostasis
What drug blocks aldosterone receptors?
Effects of Aldosterone on:
1. Increases reabsorption
2. Facilitates passive excretion
Describe the Renin-Angiotensin System
Juxtaglomerular apparatus secretes renin
Renin cleaves angiotensinogen to angiotensin I
Angiotensin I converted to angiotensin II by ACE (Angiotensin Converting Enzyme)
Describe ACE Inhibitors
Prevent Angiotensin II synthesis
Decrease aldosterone synthesis
Decrease Na reabsorption, ergo water reabsorption
What stimulates renin synth?
Decrease in perfusion pressure (baroreceptors)
Hypotonic fluid in macula densa (chemoreceptors)
Sympathetic innervation in response to decrease in plasma volume
Describe Primary aldosterone excess
Hyperactive tumors of the adrenal gland (rare)
Cause hypokalemia and hypertension/hypernatremia
Describe Secondary Aldosterone excess
Decreased effective blood volume (edema)
Sustained high levels of renin
What is the primary function of adrenal androgens?
Maturation of secondary sex characteristics
What is the major function of the adrenal medulla?
Secrete catecholamines (epinephrine, norepinephrine)
Allows for systemic stress response
What are the secretory cells of the adrenal medulla?
Chromaffin cells - secrete catecholamines
Regulated by sympathetic NS
What are the receptor types for catecholamines?
A and B adrenergic
What are the systemic responses to catecholamine release?
Cardiovascular output increase
Mobilization of energy stores
Arousal (pupillary dilation, piloerection, tachycardia)
What is the common cause of catecholamine excess?
Catecholamine secreting tumor
Yields same systemic flight or fight response