How Do Sweat Glands Work?

How Do Sweat Glands Work? What causes body odor? The milky substance reacts with the bacteria present in the skin and the byproduct of this reaction is an unpleasant, offensive smell or 'body odor'.

How Do Sweat Glands Work?

By Mr Ghaz, January 18, 2011

Image Credit

How Do Sweat Glands Work?

Image Credit

Normal body temperature is, by tradition, 37°C (98.4°F), though there are variations and daily fluctuations from person to person. It is essential, however, that the normal temperature or core temperature is kept more or less constant. If the outside temperature rises too much, the core temperature is maintained by losing heat through the sweat glands as perspiration.

Image Credit

A small amount of body heat is lost each day directly through the lungs and through the skin without involving the sweat glands at all. But, as can be imagined, this is a fairly inefficient way of losing heat. It is not a very flexible method, because you cannot increase your breathing-like a panting dog-if it gets very hot.

Image Credit

In fact, most of the heat loss that occurs every day results from perspiration. However, the liquid sweat usually evaporates from the skin before it can be noticed and for this reason it is known as ‘insensible perspiration’. It is this evaporation that allows heat to be lost. It works on the principle that liquid needs energy to evaporate-like turning boiling water into steam. In humans that energy comes from the surface of the skin, and the effect of evaporating sweat is to use up some of the heat and energy in the skin, thereby leaving you cooler. Once you have become so hot that the sweat is beginning to pour off your skin, the system has actually reached the stage where it can only just cope-it is working at its most efficient at the so-called ‘insensible’ stage.

Types of Sweat Gland

Image Credit

The body is covered in sweat glands that produce liquid. Before puberty only one set is functioning-the eccrine glands which are all over the body except in the lips and some parts of the sexual organs. There are many of these glands in thick-skinned areas such as the palms of hands and the soles of the feet, and their activity is controlled both by the nervous system and some hormones. This means that as well as responding to changes in temperature, they also react under other conditions, hence the sweaty hands of excitement and the unexpected hot flush of the menopause.

Image Credit

The other glands, the apocrine glands, are much more complicated than the eccrine glands. Under a microscope they look like worm casts-highly complicated coils. They develop and start to function during adolescence and are found in the in the armpits, the groin and the areola of the breast. They are not associated with the nervous system, but the thick milky substance which they produce does cause body odor, if the body is not washed regularly. This is because the milky substance reacts with the bacteria present in the skin and the byproduct of this reaction is an unpleasant, offensive smell or ‘body odor’.

Overheating

Image Credit

Sweat from the eccrine glands is not simply water-it consists of a wide range of chemicals found in the body, the most important of which is salt. People who sweat very heavily from working or living in a hot environment may lose up to five liters (9 pt) of liquid a day. In this case, they not only have to replace the lost fluid, but the lost salt, too-salt tablets are usually recommended. Failure to do this can result in serve muscular cramps and headaches, a condition known as heat exhaustion. It is possible, however, to adapt to living in a hot environment; the body itself adjusts and excretes less salt.

Image Credit

If the body does not adapt fully to very hot weather, a person can run the risk of suffering from heat stroke. This is a very serious condition in which the body stops sweating completely, and the core temperature rises dramatically. If the person is not quickly cooled down, brain damage may occur and ultimately death-fortunately this is an exceedingly rare condition.

Image Credit

Overheating can also be seen when people have a fever. Bacteria and viruses produce toxic substances which the body reacts to by turning the thermostat control higher. This raises the core temperature so feverish people sweat a lot.

Keeping Cool

Image Credit

The principle of perspiration as the body’s own cooling systems works most efficiently in a reasonable dry atmosphere. If it is humid as well as hot, sweat has no chance of drying off and the film of perspiration that covers the skin stops the cooling off process. This is why hot humid climates are so uncomfortable to live in, compared with hot dry climates, because it is impossible to stay cool. Likewise, tight-fitting clothes make you feel so hot and sticky-your skin is bathed in a film of sweat just as if you were in a tropical rain forest.

4 comments

Add a comment

0 answers +0 votes
Post comment Cancel
Ron Siojo
0
This comment has 0 votes  by
Posted on Jan 18, 2011
Genicuta-Andreea
0
This comment has 0 votes  by
Posted on Jan 18, 2011
chy99
0
This comment has 0 votes  by
Posted on Jan 17, 2011
Ken Brace
0
This comment has 0 votes  by
Posted on Jan 17, 2011