Loop of Henle

Question 1

1.

Answer 1

Na+ and Cl- actively transported out of ascending limb into medulla, causing a decrease in water potential down the medulla.

Question 2

2.

Answer 2

Descending limb is permeable to water so it moves out of of loop of Henle via osmosis.

Question 3

3.

Answer 3

The water potential of the surroundings tissues is lower than in the collecting duct, so water moves out of filtrate/collecting duct into medulla, making urine more concentrated. This process helps conserve water.

Question 4

Long loop of Henle

Answer 4

The longer the loop of Henle, the lower the water potential of the medulla as more ions are actively transported out of the ascending limb. This decreases the water potential of the urine as water moves out via osmosis. This conserves water so useful for desert mammals.