Functions of the Dermis
These include:
- giving mechanical protection to the body from bumps and knocks; the collagen has an important role in this function
- providing oxygen and nutrients, via blood in the tiny vessels that run in the ground substance, to the living part of the epidermis
- removing waste products of metabolism from the epidermis, which are also carried away in the blood
- providing shape and form to the body, by holding all its structures together
- contributing to skin color, particularly in people with little melanin in the epidermis.Organs in the dermis have special functions of their own
- regulation of body temperature through control of blood flow and sweating
- skin sensations of touch, pain, heat and cold.
Sweating
One of the important functions of skin is in helping to control body temperature.
All primates (a group that includes apes and humans) have glands in the skin from which they produce sweat (see Special Skin Structures) and control body temperature by evaporation (horses have them too). This sweat, which we don't notice, is called insensible perspiration. Evaporation needs heat energy, so evaporating sweat removes heat from the body and keeps down the body temperature (a process called thermoregulation). Sweat production is a response sometimes to external temperature changes, sometimes to internal stimuli - such as a highly seasoned curry! - and occasionally to stress, as a reaction to increased production of adrenalin.
Control of body temperature through sweat production is essential for life. Unfortunately this mechanism encourages effects which are now considered unacceptable, such as excessive wetness and unpleasant markings on clothing, and body odor (malodor).
Most of the sweat produced by the body comes from the eccrine glands. Up to two litres can be lost in an hour! While its primary function is temperature control, eccrine sweat also provides a useful method of removing acids and some waste products (toxins) from the body.
Men sweat more than women do; on the other hand, women have a higher perspiration pH (pH 7) compared with men (pH 5.61).