Fluid, Electrolyte, and Acid Base Balance

Fluid, Electrolyte, and Acid Base Balance

After studying this chapter, the reader should be able to

1. Explain what is meant by the terms fluid balance and electrolyte balance.

2. Compare the composition of intracellular and extracellular fluids.

3. Identify the hormones that play important roles in regulating fluid balance and electrolyte balance.

4. Describe the movement of fluid within the extracellular and intracellular fluids.

5. Discuss the mechanisms by which sodium and potassium ion concentrations are regulated to maintain electrolyte balance.

6. Explain the buffering systems that balance the pH of the intracellular and extracellular fluids.

7. Identify the most frequent threats to acid-base balance.

8. Explain how the body responds when the pH of body fluids varies outside normal limits.

9. Describe metabolic alkalosis.

10. Compare respiratory acidosis with metabolic acidosis.

Overview

The maintenance of fluid, electrolyte, and acid-base balance is crucial for life. Our cells require physical and chemical homeostasis of surrounding tissues to function. Electrolytes are ions released through the ­dissociation of inorganic compounds able to conduct an electrical current in a solution. The amount of water and electrolytes gained from food and beverages, on a daily basis, is equal to the amount the body loses to the environment. The body replaces lost water and electro-lytes and excretes any excess. Electrolytes are dissolved in the water of body fluids. When electrolyte concentra-tions are altered, water concentrations are also altered by adding or removing solutes. The reverse is also true, by either concentrating or diluting electrolyte concen-trations. This chapter provides information about fluid composition and distribution in the internal environ-ment and discusses the ways our organs function to balance fluids, electrolytes, acids, and bases.