Excretion

Process(es) by which living organisms eliminate waste products

Excretion in flowering plants

• CO2 and oxygen are the two major waste products
  • from respiration and photosynthesis
  • excreted through stomata
• Leaf fall (that occurs in many trees) may also be a way to remove metabolic waste

Excretion in humans

• Lungs
  • CO2 during exhalation
• Skin
  • Sweat containing water, urea and salt (Na, Cl ions)
• Kidney
  • Waste products in blood carried to kidney, where they are filtered out and excreted

Kidneys

Kidneys

• Location: inside ribcage towards the back
• Functions:
  • Removes waste from the blood
  • Controls water level in the body (Osmoregulation)

Nephron

Nephron