The skin is well supplied with blood vessels and nerves and has four main functions. Name the four functions and give a description of each

Question

What will be an ideal response?

Answer 1

Protection Protects against invasion by bacteria and other potentially harmful agents that might try to penetrate to deeper tissues. Protects against mechanical injury of delicate cells located beneath its epidermis or outer covering. The skin also serves to inhibit excessive loss of water and electrolytes and provides a reservoir for food and water storage. The skin guards against excessive exposure to the sun's ultraviolet rays by producing a protective pigmentation, and it helps to produce the body's supply of vitamin D.
Regulation Serves to raise or lower body temperature as necessary. When the body needs to lose heat, the blood vessels in the skin dilate, bringing more blood to the surface for cooling by radiation. At the same time, the sweat glands are secreting more sweat for cooling by means of evaporation. Conversely, when the body needs to conserve heat, the reflex actions of the nervous system cause constriction of the skin's blood vessels, thereby allowing more heat-carrying blood to circulate to the muscles and vital organs.
Sensation The skin contains millions of microscopic nerve endings that act as sensory receptors for pain, touch, heat, cold, and pressure. When stimulation occurs, nerve impulses are sent to the cerebral cortex of the brain. The nerve endings in the skin are specialized according to the type of sensory information transmitted and, once this information reaches the brain, any necessary response is triggered.
Secretion The skin contains millions of sweat glands, which secrete perspiration or sweat, and sebaceous glands, which secrete oil for lubrication. Perspiration is largely water with a small amount of salt and other chemical compounds. This secretion, when left to accumulate, causes body odor, especially where it is trapped among hairs in the axillary region. Sebaceous glands produce sebum, which acts to protect the body from dehydration and possible absorption of harmful substances.