2.67b

2.67 recall that the lungs, kidneys and skin are organs of excretion

Major organs of excretion: lungs, kidneys and skin

1) Lungs: excrete CO₂

2) Kidneys: excrete excess water, urea and salts. This helps the body control the level of water. Urea is the nitrogen waste from amino acids; we can’t store amino acids, so we excrete them as urea.

3) Skin: excretes water & salts (sweating) and a little bit of urea.