FN Flashcards
Function of water in the body fluids
- carries nutrients and wastes
- maintains structure of lg molecules
- acts as a lubricant and cushion
- aid in metabolic reactions
Function of water in fluid balance
- solvent for vitamins and minerals
- regulates body temp
- maintains blood volume
Proportions of water in body composition
males higher than females
lean individuals higher than obese
elderly higher than infants
teens higher than elderly
Intracellular fluid
fluid inside the cell
Extracellular fluid
fluid outside the cell
Interstitial fluid
fluid surrounding the cell
Intravascular fluid
fluid in the blood
Electrolyte balance
electrolytes facilitate movement of molecules across the selectively permeable membrane
Electrolytes inside the cell
potassium (K), magnesium (Mg), phosphate (P) and sulfate (S)
Electrolytes outside the cell
sodium (Na), chloride (Cl) and calcium (Ca)
Electrolyte imbalance: diarrhea & vomitting
osmosis moves water out of the cell, electrolytes and water needed to rehydrate
Hormones involved in fluid balance
antidiuretic hormone (ADH), renin, aldosterone, angiotensin
ADH
released due to dehydration
signalled by hypothalamus
conserves water & excretes potassium
Renin
enzyme released when BP is low
signalled by kidney cells
reabsorbs sodium, thus water
angiotensinogen to angtiotensin 1
stimulates adrenal glands to release aldosterone
signals kidneys to excrete potassium
Angiotensin 2
constricts blood vessels, increases BP
Fluid balance proportions
2/3 intracellular fluid
1/3 extracellular fluid