Nephron of a Kidney

Question 1

What is the function of the afferent arterioles in the renal vascular system? Efferent arterioles?

Answer 1

Afferent arterioles: carry blood (unfiltered) towards the glomerulus

Efferent arterioles: carry blood (filtered) away from the glomerulus to the vasa recta

Question 2

What is the function of the glomerulus located in the nephron of a kidney?

Answer 2

Filtration

(Blood → filtrate)

Question 3

What are the two main functions of the proximal convoluted tubule (PCT) located in the nephron of a kidney?

Answer 3

• ​Reabsorption: important molecules back into the blood (i.e. amino acids, water, salts and glucose)
• Secretion: (HUNK)

Question 4

What is the descending limb of the Loop of Henle permeable to?

Answer 4

Permeable to water.

Water exits and is also reabsorbed.

Question 5

What is the ascending limb of the Loop of Henle permeable to?

Answer 5

Permeable to salts

Salt exits and is also reabsorbed.

Question 6

[Mnemonic]

Don’t Push Adora Ilochonwu

(how to remember which limb of the Loop of Henle is permeable to water)

Answer 6

Don’t Push Adora Ilochonwu

• Descending limb is permeable to water.
• Ascending limb is impermeable to water.

Question 7

What is the main function of the distal convoluted tubule located in the nephron of a kidney?

Answer 7

• Reabsorption: salts
• Secretion: (HUNK)

Question 8

What is the main function of the collecting duct located in the nephron of a kidney?

Answer 8

Concentrates urine

(The collecting duct reasorbs water AND salt.)

Question 9

What effect does the presence of the hormone aldosterone have on the distal convoluted tubule (DCT)?

Answer 9

Causes the DCT to become permeable to water.

Question 10

What effect does the presence of the hormones aldosterone and ADH have on the collecting duct located in the nephron of a kidney?

Answer 10

Cause the collecting duct to become permeable to water AND salt.

Question 11

What is the countercurrent multiplier system created by the vasa recta and Loop of Henle in the nephron in a kidney?

Answer 11

They both flow in opposite directions, which allows maximal reabsorption of water.

• blood flows through the vasa recta
• filtrate flows through the Loop of Henle

Question 12

[Mnemonic]

Dump the H U N K

(how to remember the waste products excreted in the urine)

Answer 12

Dump the H U N K

H: H⁺ (hydrogen ions)

U: Urea

N: NH₃ (ammonia)

K: K⁺ (potassium ions)