acid-base balance Flashcards
define acid
arrhenius, bronsted-lowry, lewis
- sour taste, turns litmus red, reaction with metal = flammable gas
- arrhenius: dissociation in water = H+ion
- bronsted-lowry: substance donate hydrogen ion
- lewis: compound that is potential electron pair acceptor
define base
arrhenius, bronsted-lowry
arrhenius: dissociating to produce hydroxide
bronsted-lowry: accpts H+ ion
lewis: potential electron pair donor
pH =
-log(base 10) [H+]
strength of H ion in body.
lower pH = more H+, more acidic, stronger acid.
pH of arterial blood vs venous blood
arterial blood = 7.35-7.45
venous blood 7.30-7.40
physiological acid-base balance in body - how? 3 examples
buffer system
- carbon dioxide/carbonic acid/bicarbonate (in plasma) - CO2 that enters body enters equilibrium. bicarbonate filters out of kidney, of lung converts back to CO2 to be exhaled.
- phosphate buffer system (intracellular
- protein buffer system (imidazole groups -[ on protein, pka ~7 - easily accept/donate H+ around pH of blood], albumin [ has imidazole groups], hemoglobin)
respiratory acidosis - where is this occuring what is building up? what are some causes? compensation?
lungs cant remove enough CO2 that being produced by body. - hypoventilate
excess CO2 builds up. - increase CO2 drive equilibrium toward bicarbonate and H+ = increase H+ = increase pH, pH decreases.
cause: neuromuscular disease, cervical spine injury, CNS disease, end-stage head trauma, drug overdose, cardiopulmonary disease – heart lung disease, damage in CNS that controls respiration.
compensation: kidney reabsorbs HCO3- and eliminated H+
respiratory alkalosis - what organ is cause? - what molecule is in short supply? causes? compensation?
- lungs remove too much CO2 = hyperventilate
- deficit of CO2, pushes equilibrium towards CO2, less HCO3-, less H+ = increase pH
cause: hypoxemia (not enough O2 in system - lung compensate by breathing faster), head injury, progesterone (not serious, body recognizes slow increase - adjusts), toxins in liver disease, pneumonia, asthma, excessive controlled ventilation.(in hospital)
compensation: kidney eliminates HCO3- and reabsorbs H+ (keep H+, to decrease pH)
metabolic acidosis
body produces excess acid, kidneys dont remove enough acid, ingesting excess exogenous acid, or excess loss of bicarbonate
- body producing too much H+ (in whatever form); injest acid or thing that produces acidic metabolites; kidney isnt functioning = loss of bicarbonate.
body produces too much acid
metabolic acidosis
external to equilibrium - H+ is high , pH is low
when too much bicarbonate loss. equilibirum shift to bicarbonate but keep losing. H+ builds up = decreased pH
metabolic acidosis - causes for loss of bicarbonate
diarrhea
type 2 renal tubular acidosis
metabolic acidosis - causes for acid accumulation
CAT MUDPILES
type I and IV renal tubular acidosis
compensation for metabolic acidosis
hyperventilation removes CO2 (to pull equilibrium towards CO2) : max effect achieved in 6-12 hours.
kidney eliminates acid and reabsorbs HCO3-. pushes equilibrium to CO2 which is then breathed out. response takes 3-5 days.
CAT MUDPILES
C - CO, CN-, congenital heart failure
A- aminoglycosides
T - toluene,teophyline
M- methanol U - uremia D- diabetic ketoacidosis (or alcoholic/starvation ketoacidosis) P - paracetamol, phenformin, paraldehyde I - iron, isoniazid, inborn errors of metabolism L - lactic acidosis E - ethanol, ethylene glycol S - salicylates/ASA
metabolic alkalosis
excess accumulation of bicarbonate or excess loss of H+
rare
too much HCO3- infused = shift to CO2 = less H+ = increase pH.
straight loss of H+ = increase pH
causes of bicarbonate accumulation
causes of acid loss
a. only when infused with bicarbonate - overdo it
b. vomiting - getting rid of gastric acid, diuretics, low potassium, insufficient fluid in system, when people take too many antacids = “milk-alkali syndrome”
