The role of the loop of Henle

Question 1

what are the two roles of the loop of Henle?

Answer 1

-it allows mammals to produce a hypertonic urine
-it plays a big role in water reabsorption from the collecting ducts

Question 2

what are the two parts of the loop of Henle and what are their two features?

Answer 2

-the ascending limb which is impermeable to water and has thick walls
-the descending limb is permeable to water and has thin walls

Question 3

what are the 2 ions that the ascending limb secrete into the medulla? what process allows this to happen?

Answer 3

-sodium and chlorine
-active transport

Question 4

what happens to the medulla when these sodium chloride ions are secreted?

Answer 4

-the salt build up in the interstitial fluid in the medulla which creates a very negative/ concentrated solute potential

Question 5

what happens the filtrate as it moves up the ascending limb?

Answer 5

-as a result of the ions leaving the filtrate, it becomes more dilute and is hypotonic by the time it reaches the top of the ascending limb

Question 6

what is the net result of the very negative water potential inside the medulla?

Answer 6

-water is osmotically removed along the length of the descending limb due to its thin and permeable walls

Question 7

what happens the filtrate in the descending limb as it moves down?

Answer 7

-it becomes more concentrated as it moves down until it is hypertonic as the very bottom
-the filtrate becomes more concentrated also because of the sodium and chloride ions moving in from the medulla

Question 8

what is the main function of the loop of Henle?

Answer 8

-to create the very concentrated interstitial fluid in the medulla which facilitates the osmotic removal of water from the collecting ducts

Question 9

how are the walls of the ascending limb equip for the active transport of the sodium and chloride ions?

Answer 9

-their cuboid epithelial cells are rich in mitochondria