Skin Essay

794 Words2 Pages

I have chosen to do my essay on the largest organ of the body, skin. It has several functions vital to the survival of the body as I will discuss in the following paragraphs. The skin is an elastic covering that protects the body against exposure to dangers within our environment and makes up 15% of the weight of the body. It minimizes water loss, repels water and protects underlying structures. The dermis has blood vessels that are close to the surface to allow blood to flow and reduce the temperature of the body. It also acts as a third kidney that filters and excretes toxins.
The skin is made up of three layers; epidermis, dermis, and subcutaneous layer. The epidermis layer contains stem cells. Stem cells regenerate new skin if the …show more content…

The first layer, the epidermis, contains keratin which is a water proof protein. This makes the body water proof and keeps water from entering the body. This layer also consist of two specialized cells, langerhans cells and melanocytes. Langerhans cells are macrophages which is a white blood cell that phagocytize infectious agents. They then travel to lymphatic organs. Melanocytes lye deep in the epidermis, and produces melanin. This is the main pigment for skin color. The second layer, the dermis, is a fibrous connective tissue. It is made up of dense fibrous connective tissue and consist of collagen and elastic fibers. The purpose of the collagen fibers are to allow stretching to prevent tearing of the skin; unlike the elastic fibers which only allows for normal tension for stretching, allowing movement of muscles and joints. As we age, the fibers become weaker causing the skin to wrinkle. The blood vessels in the dermis help …show more content…

They have several different factors that determine hair color such as melanin containing iron and sulfur. If there is a lack of melanin, the hair will be white or gray. Stem cells located in the dermis are responsible for the production of hair. The shape and texture of the hair follicle determine an individual’s hair. The growth process of hair goes through the following three phases. The anagen phase which takes approximately twenty eight days and grows about one centimeter. The catagen phase lasts for approximately two to three weeks and the blood supply to the hair is cut off. The telogen phase is the final phase also known as the resting phase, lasting approximately three

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