Fluid, Electrolyte, & Acid-Base Balance

Bodily fluids comprised of

Water and Solutes

Water is a

Universal solvent

Electrolytes

dissociate into ions when dissolved in water

Electrolytes can

conduct an electrical curren

Nonelectrolytes

do not dissociate into ions when dissolved in water

Nonelectrolytes cannot

conduct an electrical current

Extracellular Fluid (ECF)

fluid outside the cells

Extracellular Fluid take up ___ of bodily fluids

33%

Intracellular Fluid (ICF)

fluid inside the cell

Intracellular Fluid take up ____ of bodily fluids

67%

Fluid movements are regulated by

osmotic and hydrostatic pressures

Osmotic pressure

amount of force applied to a solution, preventing solvent (water) from moving across the semipermeable membrane

Hydrostatic pressure

amount of pressure exerted by a fluid onto the semipermeable membrane

Water moves freely along ____ gradients

osmotic

Osmolality

moles of solute per kg of wate

ECF gets more solute

water leaves cell

ECF loses more solute

water enters cell

Water intake must equal

water output

Dehydration

the loss of water OR the loss of water and solutes together

Edema

Atypical accumulation of interstitial fluid (IF) in tissue

hydrostatic edema

Increased fluid flow out of blood

osmotic edema

Decreased fluid return to blood

Salts control ____, provide ____ for excitability

fluid movements, minerals

Sodium-water balance is linked with

BP and blood volume control mechanisms

Hyponatremia

inadequate amounts of sodium

Hypernatremia

excessive amounts of sodium

Hypokalemia

inadequate amounts of potassium

Hyperkalemia

excessive amounts of potassium

Hypokalemia occurs from

fluid loss from vomiting & diarrhea

Hyperkalemia is caused by

renal failure & K+-sparing diuretics

Calcium and Phosphate Regulation

Important for blood clotting, membrane permeability, & neuromuscular excitability

Hypocalcemia

inadequate calcium

Hypercalcemia

excess calcium

Normal pH

7.35 – 7.45

acidosis

<7.35 pH

alkalosis

>7.45 pH

Strong acids & bases

will completely dissociate in water

Weak acids & bases

only partly dissociate in water

Chemical buffers

compounds resist pH changes caused by strong acids/base

Physiological buffers

Use processes such as respiration & filtration to alter blood pH

alkaline reserve

free-floating HCO3- ions

Hyperventilation

increased respiratory rate & depth

Hypoventilation

decreased respiratory rate & depth

hypercapnia

PCO2 gets too high

hypocapnia

PCO2 gets too low

the most important respiratory function indicator

PCO2

Respiratory Acidosis

CO2 accumulates in blood

Respiratory Alkalosis

CO2 eliminated from blood faster than produced

renal pH regulation

Eliminate acids from cellular metabolism

Metabolic Alkalosis

HCO3- accumulates in blood

Metabolic Acidosis

HCO3- eliminated in excess

Renal malfunction leads to

Respiratory compensation

Respiratory malfunction leads to

Renal compensation

Partially Compensate

pH will remain low/high

Fully Compensate

pH will be corrected to neutral