acid base Flashcards
what does the maintenance of plasma [H+] depend upon?
depends heavily on buffers and excretion of CO2 and nitrogenous waste
what is the average acid production in a day?
total co2 = 25 mol/day
unmetabolised acids = 50 mmol/day
plasma [H+] = 40nmol/L
where does glucose metabolism take place?
mainly skeletal muscle and RBCs
what is the intermediary anaerobic process for glucose?
glucose = 2 lactate + 2 H+
what is the incomplete ketogenesis metabolism for triglycerides?
triglycerides = free fatty acids + H+
free fatty acids = ketones + H+
how is amino acid metabolism (urea genesis)?
neutral amino acids results in the generation of H+
what is the basic definition of a buffer?
a buffer is a solution which resists change in pH when an acid or base is added
what is pH?
pH = -log10[H+]
what is academia?
low blood pH
what is acidosis?
abnormal process or condition that lows arterial pH
what is the acid disassociation constant?
Ka
what is the negative logarithm of Ka?
pka
what is the pka equation?
pKa= -log10Ka
what does the Henderson-Hasselbach equation explain?
explains how acids and bases contribute to pH and therefore H+?
why in physiology does bicarbonate act as a base and CO2 an acid?
CO2 is acting as an acid when dissolved in plasma, CO2 becomes an acid, which dissociates to release H+.
HCO3- accepts a proton to form carbonic acid , which is converted to CO2 for excretion in the lungs
what does blood ph depend upon?
depends not on absolute amounts of CO2 or HCO3 but on the ratio of the two?
what is the pKA of bicarbonate buffering in blood?
6.1
why can’t bicarbonate buffer CO2?
because of the equation
H+ + HCO3- = H2CO3 = CO2 + H2O. which would mean buffering by bicarbonate would only result in the production of more CO2
what is mono hydrogen phosphate and dihydrogen phosphate important buffers in?
they are important buffers in urine?
NH3 is an important buffer in?
urine
what forms a buffer pair in ammonia?
ammonium ions
what is the principle non-bicarbonate buffer?
haemoglobin
what does the buffering system Haemoglobin do?
it reduces CO2.
it increases production of HCO3-
formation of HHb from Hb
what is the main predominant plasma protein buffer?
albumin
where are the sites of acid-base metabolism?
liver
lungs
kidneys
GI tract
what is the Acid-Base in the lungs?
in a healthy person, the rate of elimination is equal to the rate of production so that blood pCO2 remains constant
what is the acid-base in the kidneys, in a nutshell?
excretion of H+ ions in the distal tubule
reabsorption of bicarbonate in the proximal tubule
regeneration of bicarbonate in the distal tubule
