NURSE-UN24 - A_E I Exam 3 Study Guide.

NURSE-UN24 - A_E I Exam 3 Study Guide/NURSE-UN24 - A_E I Exam 3 Study Guide. Week 9: Fluid and Electrolyte Imbalance  Fluid surrounds all the cells in the body and is also inside cells. Body fluids contain electrolytes such as sodium and potassium; they also have a certain degree of acidity. Fluid, electrolyte, and acid-base balances within the body maintain the health and function of all body systems; the characteristics of body fluids influence body system function because of their effects on cell function. These characteristics include the fluid amount (volume), concentration (osmolality), composition (electrolyte concentration), and degree of acidity (pH). All of these characteristics have regulatory mechanisms that keep them in balance for normal function.  Water makes up about 80% of body weight in children, 60-65% in adults, and even less in older adults (about 45-50% due to decreased renal decrease thirst perception decrease muscle mass adipose tissue older adult). o Obese people have less water in their bodies than lean people because fat contains less water than muscle.