Renal Structure-Function – Glomerulus

Question 1

• What is the functional unit of the kidney?

Answer 1

The nephron

Question 2

• What makes up the renal corpuscle?

Answer 2

Glomerulus and the Bowman’s capsule

Question 3

• What makes up the renal tubule?

Answer 3

Proximal convoluted tubules, loop of Henle, distal convoluted tubules

Question 4

• What three main mechanisms occur in the nephron?

Answer 4

Filtration, reabsorption, secretion

Question 5

• What is renal clearance? And what does it depend upon?

Answer 5

A measurement of the kidneys ability for excretion, depends upon GFR, tubular reabsorption and tubular secretion

Question 6

• Which three components of the glomerulus contribute to the glomerular filtration barrier?

Answer 6

Endothelial cells of glomerular capillary wall, glomerular basement membrane, podocytes

Question 7

• What marker substances can be used to determine GFR?

Answer 7

Inulin, creatinine & Tc-99m DTPA

Question 8

• Why is creatinine only a close approximation of GFR?

Answer 8

Because it is freely filtered by the glomerulus

Question 9

• What is GFR?

Answer 9

The volume of fluid filtered from the glomerular capillaries into the Bowman’s capsule per unit time

Question 10

• What factors determine GFR?

Answer 10

Hydrostatic pressure, molecular size, electrical charge

Question 11

• What happens to the net filtration pressure?

Answer 11

Changes towards the end of the capillary

Question 12

• What determines the hydrostatic pressure?

Answer 12

Cardiac output generates pressure, afferent and efferent arterioles determine relative pressure

Question 13

• What is the charge of the filtration barrier?

Answer 13

Net negative electrical charge

Question 14

• What molecules are filtered without restriction?

Answer 14

Small molecules with molecular weight less than 7000 Daltons and all ions

Question 15

• How is GFR regulated?

Answer 15

Autoregulation, sympathetic tone, tubuloglomerular feedback, mesangial cells