With an area of one and a half to two square meters, the skin is the largest sensory organ of the human body. It accounts for about one-sixth of the body’s weight. However, the skin is not only an extremely extensive organ, but also a very delicate one. On average, it is only a few millimeters thick. The extremely thin body covering is divided into three layers: Epidermis, dermis and hypodermis.
Protective shield epidermis
The epidermis is only about 0.1 millimeters thick – on heavily used parts of the body, for example the soles of the feet, it can be up to five millimeters as callus. The surface of the skin is covered with a thin layer of water and fat, which keeps it supple and protects it from bacteria and fungi. The top layer of the epidermis consists of dead cells, keratin. These keratinized and glued together cells form a very resistant protection against mechanical and chemical stimuli. Underneath are various layers of horn-forming cells, called keratinocytes, which constantly divide and produce replenishments for the protective shield. These cells rest on the basement membrane, the boundary layer to the underlying dermis. Nutrients are absorbed through them and metabolic waste products are disposed of. The pigment cells or melanocytes, which produce the brown pigment melanin for the body’s own sun protection, are located in the lowest cell layer of the epidermis. Above them, defense cells of the immune system, the so-called Langerhans cells, are found here.
Robust, elastic and sensitive – the dermis
The dermis, also called the dermis or corium, consists of two layers: a thin upper zone of loose connective tissue and a thicker lower layer with horizontal bundles of strong connective tissue fibers (collagen fibers). The dermis contains blood vessels as well as nerve fibers with special end organs for sensing pressure, touch, pain, temperature and itching.
The subcutis – the fat store
The hypodermis consists primarily of fatty tissue, which is divided into individual fat lobules by strands of connective tissue. Due to the high proportion of fat cells, which serve as cold protection and energy storage, this layer of skin is also called subcutaneous fat tissue. This is where the larger blood vessels and thicker nerve fibers run. The hair roots, sebaceous glands and sweat glands are also at home here.
The skin – a real all-rounder
When it comes to functions, the skin also occupies a top position. For example, it serves as
- Protective shield of the body against the environment
- Protection against heat and cold
- Protective cover against pathogens and radiation
- Storage for nutrients and water
- Excretory organ for degradation products of metabolism
- Absorption organ for drugs and hormones
- Sensory organ
The skin – mirror of the soul
Sayings like “It gets under your skin”, “She is flushed with shame”, or “I could go off the deep end” show how much skin and soul are connected. The redness from joy, shame or anger is caused by the fact that the blood circulation of the facial skin is driven up for a short time triggered by certain hormones. Pale with fright, on the other hand, is caused by a reflex increase in blood flow to the heart. Whether it is the pleasant or unpleasant shiver that runs down your spine or your hair stands up in fright, it is always caused by a sudden contraction of the skin. In addition to these short-term effects, the emotional state can also trigger longer-lasting impairments of the skin. Stress, grief and other psychological burdens can lead to the sudden formation of red spots or skin blemishes. Hypersensitive reactions to environmental influences, not wearing the usual cream or perfume can also be triggered. Conversely, positive moods also have a positive effect on the skin. Those who are balanced and happy seem to radiate from within.
