Skin is an outer covering which protects the body from the environmental factors such as cold, sunlight, dampness but also from harmful substances and germs. It is one of the largest organs of the human body.
The integumentary system also plays an important role in regulating the body temperature. We pick up the sensory information through skin: that’s how we feel hot, cold, itch, pain and pressure. This function of the skin also helps us in the defensive mechanism. For example, if our hand accidentally touch a hot burner on the stove we automatically pull it back.
Skin is the production site of vitamin D with the help of sunlight1.The integumentary system has a functional barrier which protects the body from evaporating water loss. Babies born prematurely do not have an effective skin barrier and suffer from water loss2.
The skin has two types of sweat glands. The eccrine glands are distributed all over the skin surface. These glands produce a salty liquid which gives the function of the cooling mechanism when it evaporates from the skin. Due to slightly acidic nature of this liquid, the growth of bacteria that live on the skin is retarded.
The apocrine glands are situated on the genitals and under the armpits. At puberty, the apocrine glands start secreting a mixture of fat and protein. Bacteria can thrive in these environments and cause the production of body odors3.
The bottom layer of the skin is a subcutaneous fat layer. This layer provides insulation, acts as a reservoir of energy and give us our body shapes. The superficial layer of the skin, epidermis, contain melanocytes which produce the melanin pigment. Melanin gives skin and hair their color. It also protects us from the sun damage by absorbing ultraviolet light4.
Langerhans cells reside in the superficial layer of the skin. They provide protection to the body against the microorganisms5.
The integumentary system (skin) helps to diagnose a medical condition by showing the signs with changes in its structure or color. For example, people with a low number of red blood cells in their blood may look pale, and people with hepatitis may have yellowish skin color6. Skin also acts as a storeroom for the body. The deepest layer of the skin stores fat, water and important metabolites in it. It also produces hormones that are very important for the whole body7.