USCR Fluids Flashcards
What is physiological homeostasis?
balance of fluids, electrolytes, acids&bases regulated by multiple processes.
These processes regulate fluid intake&output, movement of water and substances dissolved in in.
Function of fluid in the body?
transport of nutrients/waste, electrolytes, oxygen
lubricant
insulator& shock absorber
assist in regulating/maintaining body temperature
all metabolic reactions in the body occur in a fluid environment
Fluid compartments in the body?
extracellular: plasma, interstitial, intravascular
Intracellular
Transcellular fluid: cerebrospinal, pleural, synovial fluids and fluids in GI tract; separated from other fluids by epithelium.
Intracellular fluid (ICF) is all the fluid within body cells, approx. 40% of body weight. Extracellular fluid (ECF) is all the fluid outside cells; 20% of body weight, divided into: -interstitial fluid, including lymph: fluid between cells and outside blood vessels: 15% -intravascular fluid: blood plasma: 5%
What does ICF & ECF contain?
oxygen from lungs
dissolved nutrients from GI tract
excretory products of metabolism (carbon dioxide)
electrolytes
Water body composition of infant, adult, older adult?
infant: 70-80%
Adult 50-60%
Older adult: 45-55%
4 methods in which electrolytes and water move throughout the body?
osmosis
diffusion
filtration
carrier-mediated transport
What is osmosis?
water movement through a semi-permeable membrane from a low solute concentration to a high solute concentration
What is diffusion?
movement of molecules from high concentration to low concentration
What is filtration?
movement of water and solutes across a membrane from high pressure to low pressure
What is carrier-mediated active transport?
assisted movement of molecules across plasma membrane that would not otherwise be able to move
EX: sodium-potassium pump
What are electrolytes?
chemical compounds found in all body fluids, dissolved into ions
carry an electrical charge as ions and exchange for other ions with the same charge
vital for many body functions and carefully regulated
ingested and used for basic physiological processes
stored for future use or excretes
solute [solid] dissolved into solvent [liquid] (expressed as mmol/L, mmol of electrolyte per L of solvent)
What electrolytes are in ECF?
sodium
chloride
bicarbonate
What electrolytes are in ICF?
potassium
magnesium
phosphate
Function of sodium?
maintenance of fluid balance
maintenance of PH balance
transmission pf nerve impulses
important for muscle contraction
Normal serum sodium?
135-145mmol/L
What is hyponatremia?
decrease sodium level
Causes of hyponatremia?
net loss of sodium or net gain of water vomiting diarrhea excessive sweating extensive burns use of diuretics excessive water intake (polydipsia)
What is hypernatremia?
increase sodium level
Causes of hypernatremia?
net loss of fluids or excess salt intake fever diarrhea excessive intake of table salt or IV saline solution inadequate fluid intake
Signs & symptoms of hyponatremia?
Serum Na < 135mmol/L anorexia/Nausea & vomiting/abdominal pain Lethargy/confusion/apprehension seizure/coma postural hypertension tachycardia dry mm
Action demands for hyponatremia?
diet high in sodium
weighing daily
limit water intake
put safety measures in place (seizures)
Signs & symptoms of hypernatremia?
Serum Na > 145 mmol/L dry, red swollen tongue dry/sticky mm thirst oliguria postural hypertension disorientation seizures
Action demands for hypernatremia?
diet low in sodium
increase fluid intake (PO or IV)
safety measures to prevent falls
oral care
Potassium function?
maintenance of regular heart rhythm
conduction of neuromuscular impulses
muscle contraction
PH maintenance
normal potassium range: 3.5-5.0 mmol/L