The main features of the skin are its color, elasticity and sensitivity.
Skin color (light, medium or darker shade) depends on the blood circulation features and coloring pigment melanin concentrations in the epidermis and dermis upper layer. Everyone has different skin pigment content. Melanin protects the sensitive cells in deeper layers of skin from sunburn and UV exposure. In order to strengthen the protective effects of melanin, it is necessary to use special UV filters.
Skin elasticity or flexibility and tenderness depend on the degree of elasticity of dermis. Good skin elasticity is when after the strain it returns very quickly to a primary form. Skin elasticity loss is otherwise known as skin aging. One of the skin elasticity decrease factors is the subcutaneous tissue wrinkleness. Skin is being supplied with nutrious substances by blood and lymph. Thanks to these two fluids circulation skin receives nutrients, which are necessary for its development and regeneration. Same applies to skin accessories - hair and nails. From the surface of vascular (arterial) and lymph fiber network there is tiny capillary network going to the hair follicles and skin glands. As the body ages the genetic program of cell biology is changing making epidermal layer progressively thinner. Average living span for cell lasts from 100 to 48 days. Fundamental cell count decreases - 10-20% every 10 years. As sweat and oil gland secretion reduces the skin gets dryer and loss of elasticity increases.
Skin sensativity is caused by nerve fiber sensory receptors. It is about 100 nerve endings per square centimeter of skin and its total quantity in the human body is about 1 million. Nerve fiber endings access to the epidermal layer. There are several types of nerve fibers: moving nerve fibers (rise to the muscle, which owns the hair rise, and is adhering to the hair follicle); sensous nerve fibers (responsible for the body reaction to even the 1/2 degree temperature and atmospheric pressure variations), the pain and tactile nerve fibers (their receptors transmit signals to the brain), secretion nerve fibers (situated around the sweat and oil glands, regulates these gland secretion and excretion to the skin surface). Tactile and other sensory receptors are located in papilla dermis layer and have a lot of nerve endings, which react and keep a record of pain, heat, cold, pressure and other sensations.