The skin, the largest organ in the human body, is composed of three main layers:
1. Epidermis
This is the outermost layer of the skin and acts as a protective barrier. It is further divided into five sub-layers:
- Stratum Corneum: The outermost layer, composed of dead, flattened cells filled with keratin.
- Stratum Lucidum: A thin layer found only in thick skin (like the palms and soles).
- Stratum Granulosum: Contains cells that produce keratin and lipids.
- Stratum Spinosum: Contains cells connected by desmosomes, giving the layer a prickly appearance.
- Stratum Basale: The deepest layer of the epidermis, responsible for cell division and regeneration.
2. Dermis
This middle layer contains connective tissue, blood vessels, nerves, hair follicles, and sweat glands. It provides structural support and nourishment to the epidermis. The dermis is further divided into two layers:
- Papillary Layer: The upper layer, containing capillaries and sensory receptors.
- Reticular Layer: The deeper layer, providing strength and flexibility to the skin.
3. Hypodermis
This is the innermost layer of the skin, primarily composed of fat and connective tissue. It acts as an insulator, protects organs, and provides energy storage.
These layers work together to perform various functions, including protection from injury and infection, regulation of body temperature, and sensation.
