The skin is the largest organ of the body and is made up of three main layers: the epidermis, dermis, and subcutaneous fat (panniculus).
- The epidermis, the outermost layer, is composed of viable keratinocytes covered by a layer of keratin, the stratum corneum. It provides a protective barrier against the environment.
- The dermis lies beneath the epidermis and is composed primarily of collagen, a fibrous structural protein. It provides strength and elasticity to the skin.
- The subcutaneous fat layer is the deepest layer of the skin and is composed of fat cells. It provides insulation and cushioning for the body.
In addition to these primary layers, the skin also contains a variety of other structures, including:
- Hair follicles: These are small invaginations in the epidermis that produce hair.
- Sweat glands: These glands secrete sweat, which helps to regulate body temperature.
- Sebaceous glands: These glands secrete sebum, an oily substance that helps to keep the skin moisturized.
- Blood vessels: These vessels provide blood supply to the skin.
- Nerves: These nerves provide sensation to the skin.
The composition of the skin can vary depending on factors such as age, genetics, and environmental exposure. For example, the skin of infants is thinner and more delicate than the skin of adults. The composition of the skin also plays a role in the development of skin conditions, such as acne and eczema.
