2.67b Human organs of excretion

• Lung, kidneys and skin are organs of excretion
• The metabolic waste that the lungs excrete is carbon dioxide.
• Kidneys are responsible for the excretion of excess water, the molecule urea and salts.
• The skin is known to excrete water, salts and little urea.
• The skin excretes salts and water through sweat.
• The lung excretes carbon dioxide through the respiratory system.
• The kidney excretes water, salt and urea through urine.