Physiology - Kidney Structure and Function

Question 1

Why can’t urine production be turned off altogether to maintain water volume?

Answer 1

Certain waste products can only be excreted in urine

Question 2

What cells produce renin?

What is the role of erythropietin?

Answer 2

Granular cells produce renin

Erythropoietin stimulate bone marrow to produce more RBC

Question 3

What role does the kidneys have in vitamin D absorption?

Answer 3

Convert vitamin D into active form (calcitriol)

Question 4

Describe the vascular supply to the cortical nephron from artery to vein

Answer 4

Artery 
AFFERENT arteriole
Glomerulus
EFFERENT arteriole
Peritubular capillaries
Vein

Question 5

What is the name of first part of the nephron that the glomerulus sits within and the first tubular fluid is produced?

Answer 5

Bowman’s capsule

Question 6

What is the juxtaglomerular apparatus?

Certain specialised cell types are found here. What are they and what is their function?

Answer 6

Distal convoluted tubule passing between the fork between afferent and efferent arteriole

Different specialised cells are found here

• granular cells - produce renin
• macula densa - salt sensitive cells which can release chemical signalling can cause afferent arteriole to constrict - controlling blood flow to bowman’s capsule

Question 7

What are the two different types of nephrons?
What one is more common?

How can you distinguish between the two?

Answer 7

Cortical (more common)
Juxtamedullary

Juxtamedullary have a larger loop of Henle which descends deeper into the medulla
No peritubular capillaries - vasa recta instead

Question 8

What nephron is responsible for the concentration of urine?

Answer 8

Juxtamedullary

Question 9

What is glomerular fluid?

Answer 9

Plasma which has enter from the glomerulus

Question 10

What is the normal GFR rate for a healthy adult?

Answer 10

125ml/min

Question 11

If rate of absorption is greater than rate of secretion of a substance then net absorption has taken place.
Explain how you would calculate rate of reabsorption of Cl- with the following data:

• [Cl-] plasma = 110mmol/l
• GFR = 120ml/min
• Vu = 1ml/min
• [Cl-]urine = 200mmol/l

Answer 11

Check one note and look at how slides did it