structure - textversion

Hyddrolipidic film (wafer-thin)

Glands in the skin constantly produce perspiration and sebum which mix together on the surface of the skin to produce a natural protective skin cream, the hydrolipidic film (hydro = water from perspiration; lipid = fat from the sebum). Like the horny layer, the hydrolipidic film has an acidic pH value of 5.5, and is therefore a component of the skin's natural acid protection layer.

Hair

All human beings have 85,000-150,000 hairs. Those who are blond have a larger number while redheads have the fewest. An individual hair is approx. 0.08 mm thick and grows daily by about 0.1-0.2 mm. That makes a total of 30 m of hair and 6 cm? of hair tissue. Hair is 90% keratin. It grows upward from the root contained in the hair follicle. For between 2 and 6 years the root constantly produces new material, producing 80 cm of hair. Then there is a resting period of two weeks before the root starts to produce a new hair, which pushes its predecessor up towards the skin's surface until it falls out.

The horny layer (Stratum corneum)

approx. 0.02 mm thick. Dead skin cells (corneocytes) and the fatty substances that lie between them (epidermal lipids) form the horny layer, a layer that is just 0.02 mm thick. It protects against water loss (dehydration) and irritants, allergens and the pathogens that cause disease. Unlike the other layers of the skin, the horny layer is not pH neutral, but rather acidic with a pH value of 5.5. This acidic layer is indispensable as a protective barrier. Natural moisturising factors (NMF) in the horny layer retain water and therefore offer additional protection against dehydration.

Corium (dermis)

approx. 1 mm thick Elastic connective tissue composed of a rich network of blood vessels, sense end organs and nerve fibres. Hair follicles, sebum glands and sweat glands are part of the epidermis and have their bases in the dermis. Elasticity is provided by the rigid collagen and tensile elastin fibres plus the moisture rich ground substance molecules (glycosaminoglycans) stored between them. All three components are produced by connective tissue cells (fibroblasts). Changes in appearance that come with ageing (wrinkles, tired, flaccid skin) are attributable to breakages and adhesions in the fibres and the loss of ability in the ground substance to absorb moisture.

Sweat glands (eccrine sweat glands)

These produce a secretion made up of 98% water together with metabolic products and salts which cools the surface of the skin by a process of evaporation and is therefore important in regulating the temperature of the body. Fresh sweat has a neutral smell. It is only when skin bacteria break the sweat down that unpleasant body odour is produced. Secretions produced by scent glands (apocrine sweat glands) found in certain parts of the body also contribute to body odour. Sweat, or perspiration, is slightly acidic and forms part of the acid protection layer.

Sebum glands

These create a fatty substance (sebum) that protects and smoothes the surface of the skin and hair. Their activity is controlled by hormones (androgens). The fatty substance has a slightly acidic pH value and forms part of the acid protection layer.

Adipose tissue (up to 10 cm thick)

Storage organ with a thickness of up to 10 cm: if they are not used, nutrients are turned into fat and stored here until they are needed, when they are converted into metabolic energy. Cushioning fat acts as a shock absorber and heat insulator.

page up

the entire skin:
- area of 1.5-2 square metres
- 0.1 to max. 10 cm thick
- weighs 10-20 kg

per square centimetre:
- approx. 6 million cells
- approx. 6 million cells
- approx. 5,000 sense end organs
- approx. 400 cm nerve fibres
- approx. 200 pain sensors
- approx. 100 cm blood vessels
- approx. 100 sweat glands
- approx. 15 sebum glands
- approx. 12 cold receptors
- 5 hairs
- 2 heat receptors

page up

> hair

> scalp

> hair types

Set up