question_answer 5)

Describe the role of liver, lungs and skin in excretion. 

Answer:

Role in Excretion Lungs These remove large amount of CO2 (18 L/day) and also significant quantities of water everyday. Liver It secretes bile containing substances like bilirubin, biliverdin, cholesterol, degraded steroid hormones, vitamins and drugs.Most of these substances ultimately pass out along with digestive wastes. Skin The sweat and sebaceous glands in the skin can eliminate certain substances through their secretions. Sweat produced by the sweat glands is a watery fluid containing NaCI, small amount of urea, lactic acid, etc. Sebaceous glands eliminate certain substances like sterols, hydrocarbons and waxes through sebum. This secretion provides a protective oily covering to the skin.