Body fluid accounts for more than 50% of a healthy adult’s body weight and water plays a critical role in human health.
Three possible body functions are listed below. Decide which are functions of water and which are not.
Body Functions
yes or no
Acts to maintain body temperature
Protects against bacterial infections
Provides lubrication for organs

Dehydration occurs when water excretion __________________________ water intake. Individuals at risk include the elderly, infants, people exercising heavily for prolonged periods in the heat, and individuals suffering from both short and prolonged bouts of vomiting and diarrhea. Most problems associated with dehydration can be avoided if they are recognized and treated early. If left untreated, however, dehydration can lead to severe consequences including seizures, brain damage, shock, or even death.

1. One of the main functions of water in the body is to dissolve substances and facilitate their transport, which occurs in the blood flow and in the transport of transcellular substances. This allows the water to fulfill the function of:

Maintain body temperature, contributing to changes in circulation that lead to the maintenance and loss of heat.
Protection against infection, by conducting leukocytes and immune system cells to the site of infection.
Lubrication and cleaning of tissues and organs, where water is part of the bloodstream and other body fluids that remove waste products and can keep organic surfaces lubricated (urine, synovial fluid, serous fludi, among others).

2. Water balance refers to the maintenance of an adequate amount of water in the body, which depends on intake and excretion.

When water intake decreases or excretion increases, there is a water imbalance -linked to the electrolytes dissolved in it- leading to dehydration and electrolyte imbalance in the body.

These can be causes of dehydration:

a) Decreased intake, due to not having water or liquids to ingest.

b) Increased water loss due to:

increased sweating in hot environments.
Vomiting.
Diarrhea.
Polyuria, or increased urine volume.