Loop of Henle Flashcards
What does the Loop of Henle do?
It is involved in setting up an ionic salt gradient in the medulla tissue
How is water drawn out>
From the filtrate as it passes along the collecting duct through the medulla
What is the structure of the loop of Henle?
Has a descending limb and an ascending limb
What is the permeability of the descending limb?
Permeable to water, not permeable to salt
What is the permeability of the ascending limb?
Not permeable to water, actively pumps out salt
How is NaCl transported?
Out of the ascending limb
How does the ascending limb transport NaCl?
Pumps out Cl- into interstitial fluid y active transport and Na+ follows passively
What is set up as a result of transport of NaCl?
Horizontal gradient between tubular fluid and medullary interstitial fluid
What are the levels of NaCl during transport out the limb?
At each horizontal level, there is more NaCL in the medulla interstitial fluid than the ascending limb
Why does water move out the descending limb?
Increased salt concentration of the tissues fluid causes water to move out by osmosis
What is the effect of water flowing out the descending limb?
Some salt also moves in, both increasing the osmotic concentration of the tubular fluid than
What happens to excess water?
It is removed into the blood
What is the concentration of salt at the start?
It is even
What is the salt concentration during active transport of salt?
Out of ascending limb and salt concentration increases out of tubule
Wha is the salt concentration when water diffuses?
Salt gradient is established
What is set up in the medulla?
A salt gradient
What is the effect of of the salt gradient in the medulla?
Water diffuses out, conc. of urine increases, high salt conc. in medulla and is measured as high osmolarity
What is osmotic pressure?
Salt concentration
What is osmolarity?
Measure of salt concentration
What does the distil convoluted tubule do?
Makes final adjustments
What are the final adjustments made by the distil convoluted tubule?
Maintains blood pH at 7.4
Why does blood pH need to be adjusted?
body metabolism generally generates acid
What happens if blood pH falls?
H+ is actively secreted into nephron and active secretion of urea into the fluid of DCT
What occurs at the collecting duct?
Water is recovered from urine
