Our skin is important and in many ways much more than just the shell of our body! The skin is the first line of defense against harmful influences in our environment. The skin makes sure that we do not overheat quickly, hypothermia or dehydrated. The skin possesses dexterity so that we can feel things, and therefore such complex operations with our hands out. The skin makes us recognizable to people around us ... Without skin, we would not exist ...
The skin consists of three parts: the epidermis, the dermis and subcutaneous tissue.
The epidermis (in medical terminology: epidermis)
This is the outer layer of skin. This consists mainly of keratinocytes. These new cells are constantly formed in the bottom layer of the epidermis. The cells multiply by division. The newly formed corneocytes always move a bit to the surface of the skin, induced by continued recruitment of new cells are pushed upwards. When the cells high in the epidermis they come to lie dead, yet they still remain very important! This provides circumstantial cytoskeleton together a very strong armor, which is difficult to penetrate for pathogens and also dryness of the skin goes. These dead skin layer on some parts of the extra thick skin, like on the soles and palms.
Eventually peels the outer layer of the epidermis. It does not matter, since there are constantly new layers are created by cell division.
On average, the entire epidermis is replaced completely every 30 days.
There are in the lowest layer of the epidermis between the horny cells are other cells known as melanocytes. The pigment cells are small pigment granules which they transmit to hear that the pigment cells as a nuclear umbrella over their present. Thus, the fragile genetic material in the nucleus shielded against the damaging effects of ultraviolet radiation in sunlight.
The dermis (dermis)
This layer is a solid construction of connective tissue and is much more varied in content than the epidermis which after all are only a few types of cells. In the dermis we find veins (food and oxygen supply), lymphatic (drainage of waste), and nerves (sense of touch, pain conduction, temperature sensitivity).
The blood supply is a very ingenious, sophisticated system that supplies nutrients and oxygen to the farthest corners of the dermis and lower layers of the epidermis precisely controls. The blood vessels in the skin also play an important role in the temperature of the body: by dilating blood vessels may provide additional heat to the outside world be issued by vasoconstriction, the release of heat can be restricted so that no precious energy needlessly lost. The dermis is the most important part of the active defense system of the skin through a special system in which white blood cells play an important role to viruses and bacteria are identified and addressed rendered powerless.
The dermis also provides the tensile strength and elasticity of the skin. When the skin ages or damaged by sunlight, the elasticity and bounce off.
The dermis is not constantly renewed, as it happens in the epidermis. Damage to the dermis remains always visible as a scar. However, where only the epidermis is damaged it will heal without rest.
The subcutaneous tissue
This layer separates the skin from the muscles and tendons in our body. It consists mainly of fat, blood vessels and connective tissue partitions. The fat provides extra insulation of the body and is also a source of energy in times of scarcity. The thickness of subcutaneous tissue varies from place to place. This layer is particularly thin on the tibia and in the skin that lies over the joints. On the abdomen, buttocks and back, the thickness of subcutaneous connective tissue layer considerably.
In the skin, the sweat glands, sebaceous glands and hairs. These topics are discussed in skin diseases arising in these parts of the skin.