Exam 3 Flashcards
(90 cards)
osmosis
movement of WATER down a concentration gradient
-from low solute to high solute across semi permeable membrane
diffusion
movement of molecules from high concentration to low concentration
shifting of water
water follows electrolytes
colloids
substances that increase colloid osmotic pressure (oncotic pressure)
-MOVE FLUID FROM INTERSTITIAL COMPARTMENT TO PLASMA (BLOOD) COMPARTMENT
3 primary colloids: albumin, globulin, fibrinogen
hydrostatic pressure
force of fluid in compartment pushing AGAINST A CELL MEMBRANE, generated by BP, force that pushes water OUT of vascular system into interstitial space
oncotic pressure (colloid osmotic)
caused by plasma colloids (large molecules) in solution, plasma has LOTS of colloids, interstitial space has little, plasma proteins attract water, pulling fluid from tissue space INTO vascular space
electrolytes influence
fluid balance, acid base balance, nerve impulses, muscle contraction, heart rhythm, etc
what are electrolytes
substances that are electrically charged when in solution (K+, Mg+, Na+, Ca+, P-, Cl-, HCO3-)
concentrations of electrolytes are dependent on
electrolyte intake, absorption, distribution, and excretion
hyponatremia
low sodium
hypernatremia
high sodium
sodium
water follows sodium, governs osmolality, influences water distribution, aids in acid-base balance, activates muscle and nerve cells, ion movement important in action potentials
hyponatremia causes
GI losses, renal losses, skin losses, fasting diets, polydipsia, excess hypotonic fluid
S/S: confusion/altered LOC, anorexia, muscle weakness, can lead to seizures/coma
dilutional hyponatremia
hypervolemic, increased BP, weight gain, bounding pulse
depletional hyponatremia
hypovolemic, lower BP, tachy pulse, dry skin, weight loss
treatment of hyponatremia
SLOW sodium replacement, PO/IV, IV NS, fluid restriction, treat underlying problem
hypernatremia causes
IV fluids, tube feeds, near drowning in salt water-> excess sodium intake, not enough water intake or too much water loss-> cognitively impaired, diarrhea, high fever, heat stroke, profound diuresis
-S/S: altered LOC/confusion, seizure, coma, extreme thirst (hyperosmolality), dry sticky mucous membranes, muscle cramps
treatment of hypernatremia
if water loss is cause-> add water
if sodium excess is cause-> remove sodium
GRADUALLY ACHIEVE NORMAL LEVEL
hypokalemia
low potassium
hyperkalemia
high potassium
potassium
intracellular cation, helps regulate cell excitability and electrical status, helps control intracellular osmolality, diet is main source, kidneys main source of K loss-> pee out K
causes of hypokalemia
renal or GI losses, DIURESIS, acid base disorders (K in extracellular space goes into intracellular space)
-S/S: CARDIAC RHYTHM DISTURBANCES-LETHAL, muscle weakness, leg cramps, decreased bowel motility: constipation, nausea, ileus
causes of hyperkalemia
decreased K OUTPUT (renal failure, not peeing), burns, crush injuries, sepsis, anything with massive cell injury, drugs, K sparing diuretics, ACE, ARBs, NSAIDS
-S/S: cardiac rhythm disturbances, muscle weakness, cramps, abdominal cramping, diarrhea, vomiting
hyperkalemia treatment
diuretics
