question_answer 28)

  What would be the cardiac output of a person having 72 heart beats per minute and a stroke volume of 50 mL? (a) 360 mL                           (b) 3600 mL                         (c) 7200 mL                         (d) 5000 mL

Answer:

                                                      (d) Cardiac Output (i) The volume of blood pumped by each ventricle per minute is called the cardiac output. It is 500 mL or 5 liters in a healthy individual. It is determined by multiplying the heart rate with the volume of blood ejected by each ventricle during each beat, which is called as stroke volume. Cardiac output = Heart rate x Stroke volume             =72 beats/min x 0.08 litre/beat = 5.5 litre/min (iii) Cardiac index is the minute volume per sq. m. of body surface area. Its normal value is 3.3 lit/min/sq.m.