Human skin is the largest organ in the body, acting as a protective barrier against the environment. It is composed of multiple layers and is primarily made of water, proteins, and fats.
- Water: Makes up about 70% of the skin's composition.
- Proteins: Account for around 25% of the skin, with collagen being the most abundant protein. Collagen provides strength and elasticity, while keratin helps create a tough outer layer.
- Lipids: Contribute about 3% of the skin's composition, forming a protective barrier and keeping it moisturized.
- Other Components: Minerals, nucleic acids, glycosamines, and proteoglycans are also present in smaller amounts.
The skin is divided into three main layers:
- Epidermis: The outermost layer, responsible for protection and acting as a barrier against infection.
- Dermis: The middle layer, containing blood vessels, nerves, hair follicles, and sweat glands.
- Hypodermis: The innermost layer, primarily made of fat and connective tissue, providing insulation and cushioning.
The skin also hosts a diverse community of microorganisms called the skin microbiome. These microbes play a role in skin health and immunity.
