Urine Formation By the Kidney 2

Question 1

How does HTN affect endothelium derived NO?

Answer 1

In some hypertensive patients or atherosclerosis patients → the damage of vascular endothelium leads to reduced production of ENO → that may increase renal vascular resistance → elevate blood pressure!

Question 2

How do drugs which inhibit ENO production affect renal performance?

Answer 2

lead to increase renal vascular resistance → decrease GFR → decrease urinary excretion of Na+ → causing high blood pressure

Question 3

How do dopamine and bradykinin affect kidney.

Answer 3

Dilation of cerebral, cardiac & renal arterioles + constriction of cutaneous & muscular arterioles → redistribution of blood f low for the benefit of the vital organs (protective function)

Question 4

What are dopamine and bradykinin used to treat that we learned in this section?

Answer 4

Treatment of hemorrhage using a low dosage because of protective (vasodilatory) effect on blood flow in several critical organs

Question 5

How do high protein intake, hyperglycemia (i.e. in DM) affect RBF and GFR?

Answer 5

AA and glucose in the blood and proximal renal tubule (site of reabsorption)

↑ Na+ reabsorption in the proximal tubule (co-transport with AA and glucose)

decreased Na+ delivery to the macula densa

— Tubulo-glomerular feedback-mediated relaxation of the
afferent arterioles

— ↑ RBF and GFR → ↑ Na+ excretion

Question 6

Which overpowers which? Extrinsic regulation of the kidney or intrinsic?

Answer 6

extrinsic

Question 7

What is the fundamental renal equation?

Answer 7

Amount filtered + Amount secreted – Amount reabsorbed = Amount excreted

Question 8

What substance is cleared from the blood in which excretion of it equals filtration?

Answer 8

inulin

Question 9

Excretory rate formula.

Answer 9

Amount filtered/time – Amount reabsorbed/time + Amount secreted/time 12

Question 10

Mutation of nephron leads to what syndrome?

Answer 10

congenital nephrotic syndrome

Question 11

What are substances which are not freely filtered in the kidney?

Answer 11

Not freely filtered substances: proteins, lipid soluble bilirubin, lipid-soluble hormones

Question 12

Removal of negative charges of the BM filter leads to what?

Answer 12

proteinuria

Question 13

What are the characteristics of the glomerular ultrafiltrate?

Answer 13

no cellular elements

essentially protein free

iso-osmotic to plasma

concentration of small solutes is similar to plasma
Exceptions: less Ca2+ and fatty acids