Antiperspirant Awareness: It's Mostly No Sweat (cont.)
Given the amount of money people spend on personal hygiene products, it would seem that an offensive body odor shouldn't be much of a problem. However, according to Gray's Anatomy, most people have several million sweat glands distributed over their bodies, providing plenty of opportunity for odors to develop.
There are two types of sweat glands. The eccrine glands, which we are born with and which are the most numerous, produce most of the sweat in the underarms. These glands open directly onto the surface of the skin. Apocrine glands, which are triggered by emotions, develop in areas abundant in hair follicles, such as the scalp, underarms, and genitals. These glands only begin to secrete sweat after puberty, and have little, if anything, to do with temperature regulation.
The sweat glands are located in the middle layer of skin called the dermis, which is also made up of nerve endings, hair follicles, and blood vessels. A sweat gland is a long, coiled, hollow tube of cells. Sweat is produced in the coiled part in the dermis, and the long part is a duct that connects the gland to the opening, or pore, on the skin's outer surface. When the sweat gland is stimulated, the cells secrete perspiration that travels from the coiled part of the gland up through the straight tube and out onto the skin's surface.
The American Academy of Dermatology (AAD) says that perspiration is 55 percent to 60 percent fluid, mainly water. Perspiration also contains salt (sodium chloride), as well as trace amounts of other substances, such as ammonia, calcium, chloride, copper, lactic acid, phosphorous, and potassium. These substances, called electrolytes, help to regulate the balance of fluids in the body. The most abundant electrolytes are phosphorous and sodium, which cause sweat to sting the eyes and give sweat its salty taste.
The loss of excessive amounts of salt and water from the body can quickly dehydrate a person and can lead to circulatory problems, kidney failure, and heat stroke. So, although it's literally cool to sweat, it's also important that people drink fluids when exercising or when outside in high temperatures.
People tend to interchange the words "antiperspirant" and "deodorant," but as regulated by the FDA, they are not the same. Antiperspirants have an aluminum-based compound as their main, "active" ingredient, which can be any number of compounds within an established concentration and dosage form. The active ingredient gives antiperspirants their sweat-blocking ability by forming a temporary plug within the sweat duct that stops the flow of sweat to the skin's surface.