Layers of skin

The skin can be divided into three basic layers - epidermis, dermis, and subcutaneous layer.

The superficial portion of the skin is called the epidermis, and a deeper portion is called the dermis. The epidermis is built from keratinized, flattened epithelium, which creates protective and waterproof barriers for underlying tissues. The dermis consists of connective tissue providing elasticity and is a home for many structural components like hair, glands, and vessels.

Under the dermis is the last layer, called the subcutaneous layer. It is not really part of the skin; however, it provides an anchor for the dermis and connects the skin to the underlying connective tissue around muscles and bones.

Based on the location, skin can be thin or thick. Thin skin covers most body regions, and its epidermis has only four layers. Thick skin occurs in places where exposure to friction is greatest (fingerprints, palms, soles), and its epidermis has five layers.

Cross section of a skin sample. The image consists of a cross-section of a skin sample in which the three main skin layers are shown. The top and the thin one is the epidermis. On a deeper level, there is the dermis, which is the thickest layer of them all. In the dermis there is both the sebaceous gland, depicted as small and the sweat gland, with a long and curvy shape, going from the bottom of the dermis until the top of the epidermis. The hair follicle is also in the dermis but the hairs stand out from the epidermis. The dermis is the layer of the skin where the nerve endings are present and depicted as small and round. Finally, the deepest layer is the hypodermis, which is also thin and contains numerous blood and lymph capillaries, which go all the way up to the top part of the dermis.

Figure 1. Cross section of a skin sample showing basic skin layers and their internal structures.