How should we read anatomy

Human skin

The functions of the skin

Heart, kidneys, liver - these are the organs most people probably think of first. Very few people think of the skin, although it is our largest and heaviest organ.

If we could literally "get out of the skin" and then weigh and measure it, we would find that our skin weighs up to ten kilograms and, when spread out, measures up to two square meters. Nevertheless, the skin is only a few millimeters thick.

The tasks of the skin are varied. The skin holds our body together, it protects us from pressure and impacts and from the penetration of water, UV rays, dirt and microbes - in other words, tiny organisms such as bacteria and viruses. It also ensures that we do not dry out: Without this barrier function, the body would lose around 20 liters of fluid per day.

The skin regulates the body's heat balance. We also express emotions through our protective cover: We blush with anger, pale with fright, we sweat with fear. In addition, the skin is also the sensitive sensory organ with which we feel our surroundings and our fellow human beings.

The layers of the skin

Our skin is roughly divided into three layers: upper skin (epidermis), dermis (cutis) and subcutis. There is a thin film of fat over the epidermis, made up of secretions from the sweat and sebum glands. This film protects the skin from the penetration of bacteria and fungi and lets water roll off.

The horny layer lies beneath the film of fat. These are cells that are produced in the epidermis, move upwards and become keratinized here. This horny layer flakes off and is completely re-formed within around a month. Injuries that do not reach deeper than the germ layer heal completely. Deeper injuries leave a scar.

The pigment-forming cells are also located in the epidermis, i.e. in the epidermis. After exposure to the sun, the so-called melanocytes form the dye that ensures the coveted tan of the skin.

The dermis is traversed by elastic fibers, which ensure the amazing elasticity and stability of the skin. This layer is also where the blood vessels that nourish the skin are located. When a person becomes warm, they expand: heat is released to the outside. If it freezes, the vessels contract: the heat is retained in the body.

The nerve endings and receptors are also located in the dermis. They transmit stimuli such as pain, cold, warmth and pressure to the brain. The dermis is thicker than the epidermis.

The subcutaneous tissue is mostly made up of the fatty tissue that causes so much concern. The fat layer serves as a heat pad, food depot and buffer against impacts. This is where fibers originate that connect the skin with bones, tendons and muscles. The sweat glands are also located here.

Hair and nails

Hair and nails are also part of the skin. They are called skin appendages. Finger and toenails consist of a 0.5 to 0.7 millimeter thick horn plate that lies on the nail bed. In between is the cuticle, which protects against the penetration of dirt and bacteria.

Hair is made of the same material as nails. The hair roots are in the dermis. Three layers form a hair: the inner hair pulp, the pigment-containing fiber layer and the outer horny layer.

Every hair follicle has a muscle that, when irritated by cold or excitement, contracts and straightens the hair. It comes to "goosebumps". Above this tiny muscle are the sebum glands, whose greasy secretion ensures that the hair remains supple. Your production figures decide whether we reach for a shampoo for normal, dry or oily hair.

As the skin ages

The skin changes with age. It becomes thinner, drier and the notorious skin folds appear. Unlike young skin, the cells of older skin store less water. In addition, less of the protein collagen is produced and more of it is broken down. Collagen is a structural protein that is built up in the dermis and is the main component of elastic fibers.

When it comes to visible aging of the skin is different for every person. The way people live and their genes influence the texture of the skin.

The skin is particularly bad when it is exposed to too much sun. The UV radiation leads to premature aging of the skin and promotes the development of tumors. Those who drink a lot of water, eat wholesome food as much as possible, exercise a lot, feel good and, above all, do not smoke keep their skin rosy, young and firm for longer.

Since still nobody has found the legendary fountain of youth, we have to be content with cosmetic procedures for skin rejuvenation. Science gets to grips with wrinkles with anti-wrinkle creams, laser beams, face-lifting and the injection of collagen.

Chemical peelings based on fruit acid, which peel off the uppermost horny layer in a very skin-friendly manner, are also popular. The skin underneath looks fresher and more even, but the process has to be repeated every few months.

Skin diseases

Above all, skin diseases such as contact allergies and neurodermatitis are increasing in western countries. This has various causes: Stress, food and environmental factors such as air polluted with pollutants irritate the skin.

Our modern approach to hygiene and personal hygiene also contributes to the fact that many people, especially children, are allergic to certain substances. Other common skin diseases are eczema, psoriasis, acne, the herpes virus, fungal infections, bacterial infections and skin cancer.

Many internal diseases also evoke a reaction externally. The skin then shows when something is wrong inside. Dry and itchy skin can be a sign of diabetes.

Chinese medicine has known for 5000 years that there is a connection between our skin and our internal organs: Chinese doctors use acupuncture and various massage techniques to alleviate and cure the diseases of their patients.