What is the outermost layer of the skin called?

The outermost layer of the skin is known as the stratum corneum. This layer is part of the epidermis, which is the topmost section of the skin. The stratum corneum consists of dead skin cells that have become keratinized, meaning they are filled with the protein keratin, which provides a protective barrier against environmental damage, pathogens, and moisture loss.

This layer serves multiple functions, including protection from physical and chemical insults, as well as helping to maintain hydration by preventing excessive loss of water from the underlying layers of skin. The composition and structure of the stratum corneum are crucial for its role in skin health and overall function.

In contrast, the hypodermis, which is beneath the dermis, primarily comprises adipose tissue and serves as insulation and energy storage. The dermis lies below the epidermis and contains connective tissue, blood vessels, and various skin appendages like hair follicles and sweat glands. The stratum basale is the deepest layer of the epidermis, where active cell division occurs, leading to the regeneration of the skin. However, it is not the outermost layer.