Medical Skin Care > Understanding Your Skin > Basic Biology of Skin

Basic Biology of Skin

What is under the skin?

To understand further about the health of your skin, the first thing is to know your skin better, in terms of its structures and functions.

The skin is the largest organ of the body. It is soft, but elastic, can retain water inside the body, regulate the body temperature, and provide information of the outer environment. It comprises about 15% of the body weight. The total skin surface of an adult ranges from 12 to 20 square feet. In terms of chemical composition, the skin is about 70% water, 25% protein and 2% lipids.

Looking under the microscope, your skin can be divided into 3 main layers： Epidermis、Dermis and Subcutis，with connections to hair follicles, sebaceous glands sweat glands, nerves, blood vessels, lymph vessels and fine muscles of the hair follicles.