Essay On Epidermis

The functions of the skin are protection, body temp regulation, blood resevior, excretion, metabolic functions, and cutaneous sensations. The skin is composed of two distinct regions: epidermis and dermis. The epidermis is composed of epithelial cells and is the outermost protective shield of the body. The epidermis is a keratinized stratified squamous epithelium consisting of 4 distinct cell types (keratinocytes, melanocytes, Merkel cells, and Langerhans’ cells) and 4-5 distinct layers. The underlying dermis makes up a bulk of the skin. It is a tough, leathery layer composed of fibrous connective tissue. The dermis is the only vascularized region of the skin because of the nerves and blood vessels in the region. Thick skin covers the palms, soles of feet, and the fingertips. …show more content…
In thin skin, which covers the rest of the body, the stratum lucidum appears to be absent and the other strata are thinner. The stratum basale is the deepest epidermal layer that consists of a single row of cells, representing the youngest keratinocytes. This layer is also known as the stratum germinativum because rapid cell division occurs with the cells that make up this layer of the skin. The stratum spinosum consists of several cell layers that contain a weblike system of intermediate pre-keratin filaments. The keratinocytes in this layer appear as irregular spiny shaped cells, causing them to be called prickle cells. Langerhans’ cells are most abundant in this layer. The stratum granulosum is a thin layer composed of layers of keratinocytes that appear flattened. The stratum lucidum appears as a thin translucent band. It has a few rows of clear, flat, dead keratinocytes. This layer is only visible in thick