The leather skin, Dermis, consists of a tightly woven connective tissue that gives the skin strength and elasticity, and of blood vessels supplying the epidermis with oxygen and nutrients. Here, there are also sensing elements that detect temperature and touch.
The leather skin is the thickest layer of the skin. It is primarily a connective tissue layer that gives the skin its strength and elasticity. In addition, there are many specialized tissues in the leather skin, e.g. follicles, sweat glands, sebaceous glands and sensory cells.
The connective tissue
The leather skin is much more cellular than the epidermis. Most connective tissue cells (fibroblasts) are seen. These cells produce fibers with different properties. In the dermis, there are plenty of fibers of the materials collagen and elastin. The collagen fibers are in the family of those who cartilage is made up of and they give the skin its strength. Elastin fibers, as the name suggests, are elastic and give the skin its resilience and elasticity. In addition to fiber structures, there are other molecules which, among other things, bind water in the leather skin.
When the skin ages and wrinkles appear, it is especially because the connective tissue of the dermis becomes more sparse and the skin becomes thinner and loses its elasticity and water retention (see age changes in the skin).
As mentioned, the dermis also contains a lot of special structures. There are many glands that produce sebum and sweat. Their export pathways extend through the epidermis and end up in pores on the surface. If the sebaceous glands overproduce (as in puberty) or the pores are stopped, it can lead to infections of the glands that are seen as acne (pimples, impure skin). Also, follicles lie in the tough leather skin, and therefore hair is as firm as they do!
Finally, the dermis is rich in sensory cells. These special cells are directly connected to the nervous system and detect pressure and touch, cold and heat as well as pain from the skin to the spinal cord and brain. Some diseases occur when e.g. A virus uses the long nerve cells to spread to the skin. This applies, for example, to Cold sores and shingles, both due to a herpes virus (herpes simplex and herpes zoster, respectively).