NURS 271 EXAM #1 (All answered)

*ACID-BASE IMBALANCES* correct answers What is homeostasis? correct answers = balance between acids & bases in the body *without balance our cells can't function properly! H+ conc = measured by pH levels (inversely proportional) & are responsible for the acidity/alkalinity of the body - incr H+ conc = decr pH = acidosis - decr H+ conc = incr pH = alkalosis What pH indicates a normal acid base balance? acidosis? alkalosis? correct answers - normal pH = 7.35-7.45 - acidosis pH 7.35 - alkalosis pH 7.45 What are the normal Arterial Blood Gas (ABG) values? correct answers *we collect arterial blood to assess acid-base balance... pH = 7.35-7.45 PaCO2 (partial. pressure of CO2 in arterial blood) = 35-45 mm/Hg - indicates pts breathing effectiveness (respiratory component) HCO3- (bicarbonate) = 22-26 mEq/L - indicates effectiveness of renal regulation of metabolic acids (metabolic component) PaO2 (partial pressure of O2) = 80-100 mm/Hg - indicates pts oxygenating effectiveness SaO2 = 95-100% What are chemical buffers? correct answers = chemicals (weak. acid + base) found in all body fluids that regulate pH by combining w excess acids & bases *1st line of defense against acid base imbalances (aka buffers system) 1) bicarbonate = buffers extracellular fluid (blood & interstitial fluid) ex: respiratory & renal systems 2) phosphate = buffers intracellular & renal tubular fluids ex: renal tubules 3) protein = buffers intracellular fluid & blood ex: albumin & plasma proteins (most plentiful in body!) Explain the bicarbonate buffer system. correct answers = HCO3- (bicarbonate base) & H2CO3 (weak carbonic acid) that compose the most important buffer in extracellular fluid! - normal blood pH = normal HCO3-:H2CO3 = 20:1 *when this ratio deviates, the blood pH is altered - MOA... excess metabolic acid = HCO3- uses H+ to form H2CO3 carbonic anhydrase (enzyme) excretes H2CO3 as CO2 & H2O via the respiratory tract lack of metabolic acid = H2CO3 releases H+ ions