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Biology-Related Homework Help Anatomy and Physiology Topic started by: ppk on May 11, 2011



Title: What is the advantage of the lower relative increase in stroke volume?
Post by: ppk on May 11, 2011
Sabrina's resting heart rate is 80 beats per minute, and her resting stroke volume is 50 mL per beat. What is her cardiac output? When she exercises, her heart rate increases to 100 beats per minute and her stroke volume increases to 55 mL per beat. What happens to her cardiac output? What is the advantage of the lower relative increase in stroke volume?


Title: Re: What is the advantage of the lower relative increase in stroke volume?
Post by: bio_man on May 14, 2011
CO = HR × SV. CO = 80 beats/min × 50 mL/beat = 4000 mL/min at rest. During exercise: 100 beats/min × 55 mL/beat = 5500 mL/min. Overstretching of the heart muscle during venous return could damage it; thus a relatively higher heart rate is a safer way to increase cardiac output.