Regulation of Blood Osmolality Flashcards
Where is aldosterone produced ?
IT is a mineralcorticoid produced in the adrenal cortex
What stimulates aldosterone secretion ?
Plasma K+ and angiotensin will stimulate secretion. Plasma Na will inhibit secretion
Where does aldosterone work ?
Distal tubule and collecting duct where it increases Na+ absorption
How does aldosterone work ?
It stimulates synthesis of the NaKATPase on the basolateral membrane. Increasing Intracellular K+ and lowering Intracellular Na+.
- Increases open Na channels and NaCl transporters
- Increases synthesis of Krebs intermediates to make more ATP
How quickly does aldosterone work ?
Slowly because it has to transcribe and translate all of these proteins
Where is Atrial Naturietic Peptide produced ?
In the right Atrium and is released upon atrial distention
When is ANP secreted ?
In response to P(Na) increase but the direct stimulant is ECFV distention.
What are the effects of ANP ?
It will decrease plasma aldosterone, decrease tubular Na reabsorption, dialate the efferent arteriole increasing GFR and increase sodium excretion
-Inhibits Aldosterone secretion in the adrenal cortex
What are Ouabain Like factors ?
They are produced in the atrium and induce diuresis and natriuresis.
Where are prostaglandins produced and what do they do ?
Prostaglandins are produced in the kidney and cause diuresis and natriusis
In a state of volume depletion what three cascades will be activated ?
AVP- increases renal water retention despide a low osmolality
Renin cascade- Inc aldesterone and increased Na reabsorption
Norepinephrine- Inc afferent and efferent tone which will decrease GFR
What three cascades will be activated in the condition of volume expansion ?
Supression of hypovolemic hormones
Release of naturietic hormones ( ANP, Oubain like factor )
Peritubular factors
