How Skin Cells Are Formed, Grow, and Die - Essay Example

Chemically, the skin is made up of 70 per cent of water, 25 per cent of protein, and 2 per cent lipids. The rest is trace minerals, glycosaminoglycans, nucleic acids, proteoglycans, and other chemical elements. The process by which human skin renews itself is highly ordered and runs systemically. Cell proliferation, cell migration, and remodelling of tissue are components of this process. 

Epidermis, which is a visible part, is made up of keratinocytes or keratin-producing, melanocytes and Langerhans cells (Madison 231). The keratin-producing cells are responsible for protein (keratin) production and they make up the most of epidermis. While the epidermis is around 1mm or less thick, its least mature keratinocytes lay are the lowest portion. Just as they mature, they lose water, grow flat and go upward. Finally, when their life cycle comes to an end, they move to the uppermost epidermis layer known as the stratum corneum.

The latter is predominantly made up of dead keratinocytes, proteins (keratin), as well as lipids, and forms a crust that has a protective role. The cells from the stratum corneum slough off after they die. They are continuously replaced by those cells that come upward from below. It takes around 3-5 weeks for the human skin to renew itself completely. Melanocytes are skin cells that are responsible for melanin production and therefore for skin colour and tone. Lastly, Langerhans cells prevent harmful substances from coming through the skin.

Another skin layer is the dermis. It is an inner layer of skin cells that is quite thin. Because of a lack of blood vessels, the epidermis is not able to launch any kind of cell regeneration (Proksch 1063). The dermis, in its turn, feeds nutrition to the epidermis. It houses the connective tissue, nerve endings and blood vessels, plus it contains hair follicles and sebaceous glands. Thousands of papillae, which serve as capillaries' source, provide nourishment and are crucial for new skin cell growth. Subcutaneous tissue is predominantly made of fat cells (adipocytes) (Stücker et al 985).

The process of skin cell formation and growth takes place through mitosis which happens at the innermost skin layers. Mitosis is a type of cell division (another one is meiosis). It is a duplication process. Specifically, it is about producing two “daughter” cells that are genetically identical to one “parent” cell (Saltsman, “Inside the Cell”). The function of mitosis is, above all, to replace those cells that are lost in everyday life through wear and tear. When the replenishment of human skin takes place, cells go up the given strata as they change their composition and shape accordingly, and then these cells differentiate and get filled with keratin.

They eventually get to the uppermost layer (stratum corneum), which is made up of multiple layers of already dead cells, keratin-strengthened and water-resistant. The overall process is known as keratinisation. As has previously mentioned, dead cells slough off afterwards, which happens within weeks.