Fluids & Electrolytes Flashcards
what is an electrolyte?
a compound that releases ions when in water
what are cations?
positive charged ions
what are anions?
a negative charged ion
what are strong electrolytes?
a compound that seperates into ions in water and conducts an electric current in water
ex: NaCl + H2O = Na+ + Cl-
what are non-electrolytes?
dissoves as molecules in water
doesn’t produce ions in water
no electric current in water
what part of the body contain electrolytes?
all body fluids
what are functions of electrolytes?
1) co-factor for optimal enzyme activity
2) maintains fluid balance (osmosis)
3) maintains acid-base balance (pH)
4) carries electrical currents
what are 3 major fluid compartments that electrolytes are composed?
intracellular fluid
plasma
interstitial fluid
what is the composition of electrolytes in extracellular (interstitial fluid/plasma) fluid?
1) na+ = major positive charged ion
both similar in plasma and interstitial fluid
2) Cl- = major negative charged ion
anion concentrations similar in both EXCEPT protein (higher in plasma)
what are the intracellular electrolyte composition?
K+ = major positive charge ion (cation)
Mg2+ = important to activate enzymes
phosphate = major negative charged ion (anion)
larger concentrations of protein anions
what is a weak electrolyte?
produces few ions
some does not completely seperate
what is acid?
a solution with excess H+ (hydrogen) ions
“sharp/sour”
what is a base?
a solution that has an excess of OH- (hydroxide) ions
“alkali)
substances that can accept hydrogen ions
what is a buffer?
a solution that resists change in pH on the addition of an acid/base
typically a mixture of a weak acid/salts acts as a weak base
what is pH?
a measure of how acidic or basic a solution is
p = potential
h = hydrogen
low pH = higher concentration of hydrogen ions
what is the range of a pH scale and what is considered acidic, basic, and neutral?
range = 0-14
acidic = < 7
basic = > 7
nautral = 7
how big of a jump is each pH level to one another?
10x
ex: pH 3 is 10x more hydrogen as pH 4 due to inverse scale
what are sources of acids?
CO2 released from total combustion of carbs
large amounts of acids from normal metabolic processes
nitrogeneous waste
HCl from gastric juices
what are sourcs of bases?
bile salts + pancreatic juice
intake of alkaline drugs
what are 3 lines on defence to regulate pH?
1) blood buffer
2) respiratory regulation
3) renal regulation
what is the blood buffer system?
minimize change in hydrogen ions by converting strong acids + bases into weaker ones chemically
weak acid + its salt
- in any buffer system
- changes to weaker ones
- works in fractions of a second
what is respiratory regulation?
carbonic acid is dissolved as CO2 in plasma
hyperventilation lowers co2 + H2CO3 ( carbonic acid) int plasma
decreased/inadequate ventilation raises CO2 + H2CO3 in plasma
what is renal control?
kidneys slectively retain/excrete H+ ions
reabsorb bicarbonate form urine
kidneys play a major role in preventing a change in pH
what is the function of a buffer?
resist change in pH when strong acid/base is added to the solution
what comprises of the carbonic/bicarbonate buffer system?
carbonic acid (H2CO3) = weak acid
sodium bicarbonate (HCO3-) = weak base
what happens when a strong acid is added to a buffer system?
sodium bicarbonate converts strong acid to weak acid (carbonic acid) to resist change in pH
what happens when a strong base is added to a buffer system?
carbonic acid converts strong base to weak base (sodium bicarbonate) to resist change in pH
how do protein buffer systems work?
3 amino acids can act as buffers
free amino group ends with 2 hydrogen, but can act as a base (absorbs an extra H+) if pH falls
free carboxyl group (COOH) group ends at right end of amino acid and can act as a donor of hydrogen if pH rises
what is acidosis?
blodd pH under 7.35
very acidic
what are 2 causes of acidosis?
abnormally high Pco2 in systematic aterial blood
inadequate exhalaion of CO2
what is metabolic acidosis?
abnormally low HCO3- in stsematic arterial blood
what is alkalosis?
blood pH above 7.45
very basic
what are 2 causes of alkalosis?
abnormally low Pco2 in systematic arterial blood
hyperventilation due to high altitudes
what is metabolic alkalosis?
abnormally high HCO3- in stematic arterial blood
what does hyperventilation and hypoventilation cause?
respiratory acidosis (hyperventilation)
respiratory alkalosis (hypoventilation)
