Minggu, 19 Agustus 2012

Why do we sweat ?


Why do we sweat ?
Perspiration, or sweat, is your body's way of cooling itself, whether that extra heat comes from hardworking muscles or from stress.
The average person has 2.6 million sweat glands in their skin! Sweat glands are distributed over the entire body  except for the lips, nipples and external genital organs. The sweat gland is in the layer of skin called the dermis along with other "equipment," such as nerve endings, hair follicles and so on.

Basically, the sweat gland is a long, coiled, hollow tube of cells. The coiled part in the dermis is where sweat is produced, and the long portion is a duct that connects the gland to the opening or pore on the skins outer surface. Nerve cells connect to the sweat glands.
There are two types of sweat glands:
Eccrine - the most numerous type that are found all over the body, particularly on the palms of the hands, soles of the feet and forehead
Apocrine - mostly confined to the armpits. They typically end in hair follicles rather than pores.  The former regulates body temperature,and is the primary source of excreted sweat, with the latter only secreting under emotional stresses, rather than those involved with body dehydration.

Eccrine sweat glands are controlled by the sympathetic nervous system and, when the internal temperature of the body rises, secrete a salty water based substance to the skin’s surface.This liquid then cools the skin and the body through evaporation, storing and then transferring excess heat into the atmosphere.

Both the eccrine and apocrine sweat glands only appear in mammals and, if active over the majority of the animal’s body, act as the primary thermo regulatory device. Certain mammals such as dogs, cats and sheep only have eccrine glands in specific areas- such as paws and lips -warranting the need to pant to control their temperature.

When the thick, odorless fluid from our apocrine glands sits on our skin, bacteria act upon it,which is what makes us smell.

Apocrine glands contain proteins and fatty acids, making their secretions thicker and giving them a milky or yellowish color.

Men tend to produce more sweat than women.

Sweat is made from fluid in your blood, which means that the more you sweat, the thicker your blood becomes and the harder your heart has to work to pump that blood.

An hour or two before exerting yourself outdoors in the heat, drink 16 ounces of water or sports drink, then take in between 5 and 12 ounces every 15 to 20 minutes while working or exercising,says Runner’s World magazine.

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