18. Elements of Renal Function and Excretion

Question 1

What are the functions of the kidneys?

Answer 1

Regulate volume and composition of the ECF
Eliminate toxic metabolic wastes and foreign compounds
Convert vitamin D to its active form
Produce erythropoietin

Question 2

What are the 2 parts of the nephron?

Answer 2

The renal corpuscle

Tubular system

Question 3

What is contained in the renal corpuscle?

Answer 3

Glomerulus

Bowman’s capsule

Question 4

What processes are performed by the nephron?

Answer 4

Filtration
Reabsorption
Secretion

Question 5

What is ultrafiltration dependent on?

Answer 5

Generation of strong hydrostatic pressure in the nephron

Question 6

What is the blood supply to the kidneys?

Answer 6

Renal arteries

Question 7

What is the blood flow to the kidneys every minute?

Answer 7

1L

Question 8

How much filtrate is produced every day?

Answer 8

180 litres

Question 9

How much filtrate is reabsorbed every day?

Answer 9

178.5L

Question 10

Which substances are actively reabsorbed?

Answer 10

Glucose, AAs, Na+

Question 11

Which substances are passively reabsorbed?

Answer 11

Water, Cl-

Question 12

What are the steps in trans-epithelial transport?

Answer 12

1. Substance leaves tubular fluid
2. Passes through cytosol of tubular cell
3. Crosses basolateral membrane
4. Diffuses through interstitial space
5. Penetrates capillary wall to enter blood plasma

Question 13

What percentage of Na+ and water is collected in the PCT?

Answer 13

Na+: 67%

Water: 65%

Question 14

What percentage of Na+ and water are reabsorbed in the loop of Henle?

Answer 14

Na+: 25%

Water: 15%

Question 15

What percentage of Na+ and water are reabsorbed in the DCT and collecting duct?

Answer 15

Na+: 8%

Water: 20%

Question 16

What substances are secreted into the tubules?

Answer 16

H+, K+, organic ions

Drugs, food additives, envrionmental pollutants

Question 17

How much urine is formed per minute?

Answer 17

1ml