How does skin provide first line of defence against diseases?

The first line of defense:

1. Innate immunity is naturally inherited before birth.
2. It provides a self-defense mechanism for our bodies.
3. There are two orders of self-defense mechanisms.
   i) The first line of defense
   ii) The second line of defense
4. The first line of defense refers to the physical or chemical barriers that primarily try to defend the body from any infection.
5. The body parts that are involved in the first line of defense are- the skin, mucous membrane, and tear glands.

Roles of skin as the first line of defense:

1. The skin prevents the entry of microbes into the body.
2. Skin secretes oil from the oil glands and sweat from the sweat glands that kill the microbes.
3. Thus, skin acts as a physical barrier and prevents various infections.