Kidney function SDL

Question 1

Why would low blood urea limit an animals ability to concentrate urine => polyuria?

Answer 1

less urea to be absorbed into renal medulla => lowers medullary conc gradient => less ability to concentrate urine

Question 2

Why would polyuria => low blood urea concentration?

Answer 2

high filtrate flow rate though nephron => not a lot of time to reabsorb urea from filtrate as it passes through collecting ducts.

Question 3

Why does hypoadrenocorticism cause polyuria?

Answer 3

aldosterone not promoting Na and water reabsorption in response to hypovolaemia

Question 4

How does hypoadrenocorticism cause high blood potassium levels?

Answer 4

Aldosterone (RAAS) causes Na and water reabsorption in the collecting duct by swapping the Na+ for K+ (maintains neutral charge)
No aldosterone => no K+ entering collecting ducts in exchange for Na+ => builds up in blood

Question 5

what is the potential effect of high blood potassium?

Answer 5

interfere with cardiac electrochemistry => fatal dysrhythmias

Question 6

What is the USG of a dehydrated animal with good renal function?

Answer 6

> 1.035

Question 7

what is the USG of dilute urine?

Answer 7

<1.008