What is the outermost layer of skin called?

The outermost layer of skin is known as the epidermis. This layer serves as the first line of defense against environmental factors such as pathogens, chemicals, and physical abrasions. It is composed primarily of keratinocytes, which produce keratin, a protein that helps waterproof and protect the skin. The epidermis is also responsible for the production of melanin, which provides pigmentation and helps protect the deeper layers from UV radiation.

The other layers mentioned serve different roles. The dermis, located beneath the epidermis, contains blood vessels, nerve endings, hair follicles, and connective tissue, making it vital for skin strength and elasticity. The subcutaneous layer, or hypodermis, lies below the dermis and is primarily made up of fat and connective tissue, providing insulation and cushioning for the body. Understanding the structure and function of these layers is essential in comprehending skin health and its response to various conditions or treatments.