Glomerular filtration

Question 1

What are the basic renal processes?

Answer 1

Filtration
Reabsorption
Secretion

Question 2

What is normal glomerular filtration rate?

Answer 2

GFR = 180 L/day or 125mls/min

Question 3

What is blood flow (mls/min) to the kidneys, and its relevant % of CO received?

Answer 3

≈ 1200mls/min, i.e. 20-25% of total cardiac output.

Question 4

What % of total blood volume is made up of plasma?

Answer 4

55%

Question 5

What is the normal filtration fraction of plasma?

Answer 5

19%

Question 6

What factors determine the filterability of solutes?

Answer 6

Molecular size/pore size
electrical charge
shape

Question 7

What basic renal processes occur at the glomerular capillaries?

Answer 7

Only filtration

Question 8

What is normal net filtration pressure?

Answer 8

10mmHg

Question 9

List some factors that affect filtration rate

Answer 9

Glomerular capillary pressure: influenced by:
Sympathetic innervation
Angiotensin II
Catecholamines

Question 10

What influences glomerular capillary pressure?

Answer 10

PGC is dependent on the afferent and efferent arteriolar diameter and therefore the balance of resistance between them.

Question 11

At what range of BP is the body able to regulate blood flow and GFR?

Answer 11

60-130mmHg

Question 12

How much fluid is excreted as urine per day?

Answer 12

1-2L/day

Question 13

What % of H20 is reabsorbed from the kidneys?

Answer 13

99%

Question 14

What % of glucose is reabsorbed from the kidneys?

Answer 14

100%

Question 15

What % of Na is reabsorbed from the kidneys?

Answer 15

99.5%

Question 16

What % of urea is reabsorbed from the kidneys?

Answer 16

50%