HOW THE SKIN PROTECTS US FROM HARMFUL INVADERS.

Our skin is part of our immune system. Immune system consists of network of cells, tissues, and organs that work together to protect our body from infectious organism such as bacteria, virus etc. Our immune system destroys any foreign particles that tries to invade our body by mounting an immune response. Our immune system is designed to identify self from non-self. Self are molecules such as proteins, that are a part of our body. Non-self refers to particles that are not made by the body. Our body recognizes this substance as potentially harmful. Example of non-self-particles are bacteria, viruses, and parasites. These organisms produce proteins called antigens that allow our body to recognize them as harmful.

How the skin protects us from these harmful invaders;

Skin; our skin is the first line of defense against pathogens. It is easier for germs to get into our body and cause an infection when there is a break in our skin. The skin is the largest organ in the body and consists of two distinct layers: the epidermis (outer layer) and the dermis (inner layer).

The epidermis has cells called Keratinocyte. Keratinocytes releases chemokine, a proinflammatory mediators when a pathogen invades the upper layers of the epidermis. Chemokines attracts white blood cells to the site of infection.

The skin produces sebum, an oily or waxy substance to help keep the skin moist. Sebum protects the body from pathogens by making the skin slightly acidic, creating an environment in which some harmful bacteria cannot survive.