Slowest acting buffer system in the body -

Ans. is 'd' i.e., Renal buffer * Not all the buffer systems begin work at the same time. Chemical buffers respond first, followed by the respiratory system and finally, the renal system :# When blood plasma pH rises above or falls below normal, chemical buffers respond instantaneously. Chemical buffers often restore blood plasma to a normal pH within a fraction of a second.# If pH remains outside the normal range for more than 1 to 2 minutes, the respiratory system changes the rate and depth of breathing. This adjusts the amount of CO2, which, in turn, afters H+ ion concentration and helps stabilize pH.# If the pH continues outside the normal range despite the involvement of chemical buffers and the respiratory system, the renal physiological buffer system becomes involved. The renal system can neutralize more acids or bases than either of the other systems; however, its the slowest to respond, taking as long as 24 hours to be initiated.