Unit Three: Kidneys Flashcards
What are nephrons?
They are the filtration units in the kidneys
What happens during ultrafiltration?
A high pressure is built up —> squeezes urea, water, ions and sugar out of the blood and into the Bowman’s capsule
The membranes between the blood vessels and the Bowman’s capsule act like filters, so big molecules like proteins and blood cells are not squeezed out
What happens during reabsorption?
As the liquid flows along the nephron, useful substances are reabsorbed back into the blood:
All the sugar is reabsorbed (active transport)
Sufficient ions are reabsorbed (active transport)
Sufficient water is reabsorbed
What happens the during release of waste?
The remaining substances (including urea) continue out of the nephron into the ureter and down the bladder as urine
Why is dialysis done?
To keep the concentrations of dissolved substances in the blood at normal levels and to remove waste substances
