Fluid, Electrolyte & Acid-Base Balance

Body Fluids Your body is 66% water Not evenly distributed – separated into compartments Able to move back and forth through the cell membranes to maintain an equilibrium

Water Balance Exists when total water intake equals total water output

Fluid Compartments Intracellular fluid – fluid inside cells [ICF] Extracellular fluid – fluid outside cells and all other body fluids Interstitial fluid- Solution that surrounds cells of eukaryotes

Edema Condition in which fluid accumulates in the interstitial compartment. Sometimes due to blockage of lymphatic vessels or by a lack of plasma proteins or sodium retention

Fluid Balance Average daily intake is 2500 ml [ fluids, food and metabolic water] Average daily output is 2500 ml [ urine, feces, perspiration, insensible perspiration]

Electrolytes Molecules that release ions in water. Can affect amount of water, pH balance, and muscle function

Electrolyte Balance Concentration of individual electrolytes in the body fluid compartments is normal and remains relatively constant. Electrolytes are dissolved in body fluids

Electrolyte Balance Because of sodium and potassium influence, water will move between compartments Example: if high [sodium], then water will move from intracellular space to extracellular space due to osmotic pressure

Acid - Base Balance Blood - normal pH of 7.2 – 7.45 3 buffer systems to maintain normal blood pH Copy Table 18.1 on page 500

Maintenance of Acid-Base Balance Respiratory System: removal of CO2 by lungs – stabilizes the ECF, has direct effect on Carbonic Acid – Bicarbonate Buffer System Urinary System: removal of H+ ions by kidneys