Blood, Electrolytes, and Intravenous Infusions
2-3
2-3. PROCESSES FOR MAINTAINING WATER BALANCE
The body must maintain fluid balance to achieve homeostasis. The body achieves this balance by adjusting fluid output to equal fluid intake so that the amount of water in the body does not change. We have three sources of fluid intake: the fluids we drink, water in the foods we eat, and water formed by catabolism of tissues. Fluid output is regulated by four organs: the kidneys (which excrete urine), the lungs (which exhale moisture, carbon dioxide, and air), the skin (which excretes perspiration), and the intestines (which excrete moisture in the feces). The volume of urine excreted is the most subject to change. The more fluid the person drinks, the greater the volume of urine excreted; the less fluid consumed, the less the urine flow. This urine regulation is accomplished by a hormone present in the blood stream.
