2.The dermis: composed of fiber, matrix and cells, can be divided into two layers.
A. Papillary layer: directly located under the epidermis, papillary, containing rich capillaries and peripheral nerve devices, in the fingertips, papillae and genital dermal papillae the number of the most, so feel particularly sensitive.
B. The reticular layer contains abundant blood vessels, lymphatic vessels, nerves, sweat glands, sebaceous glands, erectors and hair follicles. In the dermis, there are more fibers, collagen fibers, elastic fibers and polysaccharides, so that the skin has a certain resistance and elasticity, skin tightness and hardness depends on the state of this layer. If this layer of collagen fiber breaks or hardens, it will cause skin aging and wrinkles.