The Skin
The skin is our body’s largest organ. It has many important jobs such as, protecting us against heat, cold, infection and injury.
The skin has two layers, the epidermis and the dermis.
The epidermis is the top layer of skin and mainly contains flat cells called squamous cells. Under these squamous cells are round cells call basal cells and also, cells called melanocytes that make the pigment (colour) called melanin found in skin. When skin is exposed to sunlight our melanocytes produce more melanin and our skin tans.
The dermis is underneath the epidermis. The dermis contains blood vessels, lymph vessels, nerves, glands that make sweat, which help cool the body, and some glands that make sebum, an oily substance that stops the skin from drying. The sweat and sebum reach the surface of the skin through pores.