<prompt> Which of the following defines hematocrit:March 2013Number of erythrocytes in bloodPercentage of the blood, by volume, occupied by erythrocytesRatio of erythrocytes to leucocytesRatio of erythrocytes to all blood cells  <response>: Ans. B i.e. Percentage of the blood, by volume, occupied by erythrocytesHematocritIt is also known as packed cell volume PCV or erythrocyte volume fraction EVFIt is the volume percentage of red blood cells in bloodIt is normally about 45 for men and 40 for women. 