Flashcards in Sodium Balance Deck (18):
Why is sodium critical for life?
maintains normal blood volume, blood pressure and organ perfusion
How can we lose sodium and what happens?
through diarrhea, sweating and results in low ECFV, low BP and shock
When do we retain sodium?
edema, weight gain, breathing problems, heart failure
What is he min and max and the recommended amount of sodium intake per day?
min - 200-450 mg/day
max - 2300 mg/day
recommended - 1600 mg/day
Normally urine sodium excretion =
dietary sodium intake
But urine sodium excretion can decrease if
you sweat a lot or have diarrhea
If someone has cholera what happens?
lose lots of sodium from diarrhea and sweating. Little of no excretion of sodium in urine because the sodium is being retained by the collecting duct
Why does the kidney manage the excretion of sodium?
in order to maintain normal levels of ECFV
High salt diets =
high ECFV (more water out of cells), also increases BP
How does the kidney know to increase of decrease sodium excretion?
from intravascular volume or effective circulating volume (so how well blood plasma can circulate "Effective Circulating Volume) NOT from serum sodium concentration
When is intravascular volume low?
diarrhea, sweating and hemorrhage
What cardiovascular receptors assess intravascular volume?
Aterial baroreceptors, Juxtaglomerular apparatus, atrial stretch receptors
How do we get active Angiotensin 2?
First the liver releases angiotensinogen, the kidney release Renin, Renin turn angiotensinogen into angiotensin 1 then ACE turns it into active ang2
How does angiotensin 2 increase blood pressure?
Angiotensin 2 which increases blood pressure by increases resistence by constricting arterioles/ increases vasopressin which increases the reasorption of water which increases Blood volume which increase blood pressure/ increases aldosterone which increases sodium reabsorption which increase blood volume/ ang 2 also has a cardiovascular response
When is renin secreted?
in response to low blood pressure, increase sympathetic nervous system (baroreceptors), low sodium intake, diuretic theraphy, upright posture, low ECFV (diarrhea, sweating, blood loss, osmotic diuresis), reduced effective circulating volume like heart failure
What is Atrial Natriuretic Peptide?
- inhibits collecting duct sodium reabsorption, so it inhibts aldosterone (because it reabsorbs sodium at collecting duct), SNS, vasopressin, and increases GFR
When is inhibition of Renin-Angiotensin-Aldosterone System good?
aid with congestive heart failure, hypertension, reducing progression of chronic kidney disease, reducing protein loss in urine in CKD