Fluid, Electrolyte & Acid-Base Balance

Fluid, Electrolyte & Acid-Base Balance EQ: How does our body maintain a balance of water and electrolytes?

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

LEFT SIDE ACTIVITY • Draw a diagram to explain water balance

Fluid, Electrolyte & Acid-Base Balance