The Human Kidney

The Human Kidney

Main Organ
1. Maintains homeostasis (Keeping body conditions as normal as possible
Produce Urea to breakdown excess amino acids.
1. Excess amino acids come from the protein in food we eat
  1. And worn out body tissue
2. Urea is poisonous
Vital for the water balance in the body
1. Concentration changes then water moves in or out of the system by Osmosis.
  1. Could damage or destroy cells
2. Lose water constantly through the lungs as water evaporates into the air when you breath.
3. You lose water when you sweat
Remove any excess water leaving it as urine
Kidneys conserve water
Ion concentration is important
1. Take on mineral ions with food
2. Processed food is high in salt which means lots of minerals
3. Some are lost through sweat
Kidneys filter your blood then re-absorb what the body needs
1. Glucose, Amino Acids, Mineral Salts and Urea move out of the blood into kidney tubules by diffusion
  1. Blood cells are left behind
  2. All sugar then Re- absorbed into the blood by active transport
Some urea gets back into the blood by diffusion on a concentration gradient
Rich Blood supply
Urine
1. Contains waste urea with excess mineral ions and water not needed
2. Quantities depend on how much you have taken in and given out
  1. On a hot day if you drink very little you urine will be very concentrated being a dark yellow colour
  2. On a cold day if you drink a lot your urine will be dilute and colourless.

Resource summary

	Created by Jamie Whiter about 8 years ago