Sodium Balance

Question 1

Why is sodium critical for life?

Answer 1

maintains normal blood volume, blood pressure and organ perfusion

Question 2

How can we lose sodium and what happens?

Answer 2

through diarrhea, sweating and results in low ECFV, low BP and shock

Question 3

When do we retain sodium?

Answer 3

edema, weight gain, breathing problems, heart failure

Question 4

What is he min and max and the recommended amount of sodium intake per day?

Answer 4

min - 200-450 mg/day
max - 2300 mg/day
recommended - 1600 mg/day

Question 5

Normally urine sodium excretion =

Answer 5

dietary sodium intake

Question 6

But urine sodium excretion can decrease if

Answer 6

you sweat a lot or have diarrhea

Question 7

If someone has cholera what happens?

Answer 7

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

Question 8

Why does the kidney manage the excretion of sodium?

Answer 8

in order to maintain normal levels of ECFV

Question 9

High salt diets =

Answer 9

high ECFV (more water out of cells), also increases BP

Question 10

How does the kidney know to increase of decrease sodium excretion?

Answer 10

from intravascular volume or effective circulating volume (so how well blood plasma can circulate “Effective Circulating Volume) NOT from serum sodium concentration

Question 11

When is intravascular volume low?

Answer 11

diarrhea, sweating and hemorrhage

Question 12

What cardiovascular receptors assess intravascular volume?

Answer 12

Aterial baroreceptors, Juxtaglomerular apparatus, atrial stretch receptors

Question 13

How do we get active Angiotensin 2?

Answer 13

First the liver releases angiotensinogen, the kidney release Renin, Renin turn angiotensinogen into angiotensin 1 then ACE turns it into active ang2

Question 14

How does angiotensin 2 increase blood pressure?

Answer 14

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

Question 15

When is renin secreted?

Answer 15

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

Question 16

What is Atrial Natriuretic Peptide?

Answer 16

• inhibits collecting duct sodium reabsorption, so it inhibts aldosterone (because it reabsorbs sodium at collecting duct), SNS, vasopressin, and increases GFR

Question 17

When is inhibition of Renin-Angiotensin-Aldosterone System good?

Answer 17

aid with congestive heart failure, hypertension, reducing progression of chronic kidney disease, reducing protein loss in urine in CKD

Question 18

What is in a oral rehydration solution?

Answer 18

sodium chloride, glucose, potassium chloride, sodium citrate (bicarbonate is loss),