The Function of the Kidney 2 Flashcards
What happens as mineral ions enter the descending limb?
The concentration in the descending limb rises. This means that its water potential (becomes more negative). It becomes increasingly more negative the deeper the tubule descends into the medulla.
What happens as the fluid rises up the ascending limb?
Minerals leave the fluid.
What is the difference in the movement of minerals at the base of the ascending limb and further up?
At the base they move out through diffusion. Further up the ascending limb mineral ions are forced out through active transport.
What is different in the structure of the at the top of the ascending limb?
It is impermeable to water.
What is the effect of these ionic movements in the loop of Henle?
To create a higher water potential in the fluid of the ascending limb. Also decreases the water potential in the tissue fluid of the medulla . The water potential of the tissue fluid becomes lower (much more negative) the further down the loop of Henle.
What happens as the fluid passes down the collecting duct?
Water moves out of the collecting duct by osmosis and into the capillaries.
What is the name of the arrangement of the loop of Henle?
A hairpin countercurrent system.
What is the overall effect of the loop of Henle?
To increase the efficiency of transfer of mineral ions from the ascending limb to the descending limb, in order to create the water potential gradient seen in the medulla.
What happens in the distal convoluted tubule?
The fluid concentration of mineral ions is adjusted through active transport.
Where does the collecting duct take the fluid?
Back down through the medulla to the pelvis.
What happens as the tubule fluid passes down the collecting duct?
Water moves by osmosis from the tubule fluid into the surrounding tissue.
What happens to the water after it has diffused out of the collecting duct?
It enters the surrounding capillaries by osmosis and is carried away.
