The epidermis, the outermost layer of the skin, is avascular tissue, meaning it does not contain any blood vessels. This layer is responsible for protecting the body from the environment and is constantly being replaced by new cells.
The epidermis is made up of several layers, including the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. The stratum basale is the only layer that contains stem cells that divide and differentiate into new epidermal cells.
The lack of blood vessels in the epidermis means that it must rely on the dermis, the layer of skin beneath it, for nutrients and oxygen. The dermis is rich in blood vessels, which provide the epidermis with the necessary supplies.
