Physiology 2- kidney structure and function

Question 1

What are the main functions of the kidney?

Answer 1

Water balance, salt balance, maintenance of plasma volume and osmolarity, acid base balance, excretion of metabolic waste (e.g. urea), excretion of exogenous compounds (e.g. drugs), secretion of renin, secretion of erythropoietin, vitamin metabolism

Question 2

Where do the renal pyramids drain to?

Answer 2

Renal pelvis

Question 3

What is the functional unit of the kidney?

Answer 3

The nephron

Question 4

What are the functional mechanisms of the nephron?

Answer 4

Filtration, reabsorption, secretion

Question 5

Where does filtration take place?

Answer 5

Glomerulus

Question 6

What are the two types of nephron?

Answer 6

Juxtamedullary (20%) and cortical (80%)

Question 7

How are the glomerular capillaries adapted for purpose?

Answer 7

Highly permeable to water

Question 8

What is the glomerulus surrounded by?

Answer 8

Bowman’s capsule

Question 9

What is the juxtaglomerular apparatus?

Answer 9

Where the distal tubule passes between the afferent and efferent arterioles

Question 10

What does the rate of excretion equal?

Answer 10

Rate of filtration + rate of secretion - rate of reabsorption

Question 11

How is the rate of filtration of a substance calculated?

Answer 11

[Substance] in the plasma X glomerular filtration rate (GFR)

Question 12

How is the rate of excretion calculated?

Answer 12

[substance] in urine X urine flow rate

Question 13

If the rate of filtration exceeds the rate of excretion, what does this mean?

Answer 13

Net reabsorption has occurred (from nephron into capillaries)

Question 14

If the rate of filtration is less than the rate of excretion, what was occurred?

Answer 14

There must be net secretion (from capillaries into the nephron)