The human skin: Helpful terms for medical assistants
The human skin, our largest organ, is the outer covering of the human body. It has a surface area (average adult human) of 1.5 - 2.0 square metres. The branch of medicine which deals with the anatomy, physiology and diseases of the skin is called dermatology.
Anatomy and functions of the skin
Our skin is composed of three layers:
The outermost layer of the skin is the epidermis. It contains no blood vessels and is nourished by the dermis.
The layer beneath the epidermis is the dermis. It contains connective tissue, blood and lymphatic vessels, hair follicles, sweat and sebaceous glands, nerve endings and receptors for sensations. Epidermis and dermis form the cutis.
The hypodermis (also called subcutaneous adipose layer or subcutis) lies below the dermis and is made of fat and connective tissue.
The skin performs various functions such as:
protection from microbes, water loss and – to some extent – ultraviolet radiation
insulation from the cold
regulation of body temperature
sensations of touch, heat, cold and injury
synthesis of vitamin D
storage of lipids.
Skin disorders exist in many types due to a variety of causes such as: