PCO2 increase leads to:

Ans. B Shift of Oxy-Hb dissociation curve to rightRef: Ganongs Physiology, 23rd ed. pg. 611 and Ganong, I 25th ed. pg. 640-41 * Oxygen- hemoglobin dissociation curve is sigmoid 'S' shaped because binding of one oxygen molecule to heme increases the affinity of second heme molecule for oxygen and so on.Factors affecting affinity of Hb for oxygen and causing the shift of curve are:Left shiftRight Shift* This means the affinity of oxygen to Hb is increased and oxygen is bound more tightly to hemoglobin* This means the affinity of O2 to Hb is decreased which favours release of oxygen to tissue.* Factors leading to left shift are# Alkalosis or | pH# |pCO2 (CO2 ) content of blood)# |Temperature (Hypothermia)#| 2,3 DPG* Factors leading to right shift are:# Acidosis or | pH# | PCO2 (CO2 content of blood)# | Temperature (Hypothermia)# | 2,3 DPGIncreased carbon dioxide inblood will lead to respiratory acidosis, and shift curve to right.