Kidneys Biology B3

Kidneys are important organs, they rid toxic waste like urea & control amound of dissolved ions in water & blood.

Nephrons are filtration units in kidneys

1) Ultrafiltration- high pressure built up that squeezes out warer, urea, ions and sugar out of blood and into Bowman's capsule. Membranes between blood vessels and Bowman's capsule act like filters so that big molecules don't pass through but stay in blood.

2) Reabsorption-Useful substances are reabsorbed back into blood: all sugar via & sufficient ions via active transport and sufficient water

3) Release of waste-left over substances like urea continue out of nephron into ureter and down to bladder as urine

If your kidneys don't work properly then you're in trouble! Waste substances build up & you…