How can the body lose water?

1 Answer
Feb 26, 2017

Exhalation, Perspiration, Urination and Defacation.


The Human Body which is composed of more than 70% water is in a constant state of balancing the amount of water necessary to maintain homeostasis.

Water can be lost from the body in several methods.

Exhalation - When the body exhales to eliminate carbon dioxide waste from the process of cellular respiration, there is a tiny amount of water vapor that is included in each exhalation. Just exhale on a cold mirror and whatch the moiture condense on the mirrors surface.

Perspiration - The body sweats out water for the purpose of cooling the body surface during exertion and to eliminate water produced as a waste product of the process of cellular respiration. The body has two basic types of sweat glands which elimnate water through prespiratin. Eccrine glands produce perspiration that is 99% water and 1% salt. These glands are providing a moisture barrier that elimnates heat and cools the body. Apocrine glands typically also excrete bacteria with the water that can lead to body odor.

Urination - When the body filters out nitrogen waste in the form of urea and uric acid, these wastes are carried out f the body in a stream of water from the kidneys and eliminated through the urethra.

Defecation - While the large intestine is responsible to try and reabsorb water from the solid waste of the digestive tract, there is some water that is lost through defecation. However, when the colon is invected with a virus or bacterial infection the waste moves through the large intestine faster than the water can be re-absorbed and is evacuated from the body with a higher concentration of moisture in the form of diahrea.