II. Numerate functions of integumentary system.

The integumentary system, which includes the skin, hair, nails, and exocrine glands, has several important functions:

1. Protection: The skin acts as a barrier, protecting the body from harmful things in the outside world such as moisture, the cold and sun rays, harmful substances, and microorganisms.

2. Sensation: The skin contains numerous nerve endings that respond to heat, cold, touch, pressure, vibration, and tissue injury.

3. Temperature Regulation: The skin helps control body temperature through sweat and hair, and by controlling the flow of blood in the skin.

4. Vitamin D Synthesis: The skin synthesizes vitamin D from cholesterol during exposure to ultraviolet (UV) radiation in sunlight.

5. Excretion: The skin helps in the excretion of wastes and excess water from the body through sweat.

6. Immunity: The skin acts as a first line of defense against infections. It contains specialized cells that detect and fight infections and diseases.

7. Storage and Absorption: The skin acts as a storage center for lipids and water. It also has a limited ability to absorb certain substances such as vitamin D.

8. Water Resistance: The skin prevents unnecessary water loss from the body and also prevents entry of excess water during swimming or bathing.