The skin contains 25% of the body’s blood supply, which flow completely through the skin once every minute. The skin is the body’s largest organ of immunity. It is the body’s first line of defence, the boundary where self is designed from non-self, yet it is highly interactive with the environment.
Anatomy of Normal Skin
Approximately 50% of the body’s primary cells of immunity are housed in the skin at any minute. After puberty, these cells are matured in the …show more content…
When the body is exposed to too much heat, there is a rush of blood to the surface of the skin, permitting it to cool. At the same time, the perspiration glands secrete liquid to aid in the process. Sensory perception occurs in the skin, preventing damage to its ability to feel heat and/or cold, giving pleasure by the same ability to feel such things as the smoothness of satin of the softness of down. There is delayed light screening by means of melanin’s reaction to light. Melanin is a dark pigment found in the skin. It is the area where both sebum and perspiration production take place and where these two combine on the surface to form a protective film (acid mantle) which renders the skin less vulnerable to damage and attack by environmental factors (e.g. sun, wind, bacteria) and less prone to dehydration.
“pH” is a chemist’s term standing for “potential of hydrogen” and is used to describe the degree of acidity or alkalinity in the acid mantle of the skin or in a product. It is measured on a scale ranging from 0-14. The centre of the scale, 7, is neutrality (neither acid nor alkaline). A reading above 7 indicates that the substance being measured is alkaline; below 7, acid. As far as the skin is concerned, a normal pH (or normal Acid Mantle) is in the range of 4.2 to 5.6. It will vary from one part of the body to another and generally speaking, the pH of a man’s skin is lower (more …show more content…
• The Epidermis contains keratinocytes, melanocytes and Langerhans cells.
The skin, and in fact our whole body, is composed of many different types of cells. These cells have the same fundamental chemical composition but they vary in size, shape and function. The cells that comprise the outer layer of the skin are themselves a series of many layers that overlap each other, thus ensuring that cellular or other fluids cannot escape from the body via the skin except through a cut or break, or by means of special escape routes: the pore of follicles.
The outer surface of the skin is comprised of flattened dead cells. Underneath however, there are living cells, which are somewhat fuller, and the deeper one goes into the skin, the fuller and rounder the cells become. At the bottom of all the layers, there is a row of cells, which are the ones that are always growing and in the process, pushing other cells upward, the cells become flattened as they are emptied of their natural fluid through pressure and