Question

Having been lost in the desert for 2 days without water, Alexandra is badly dehydrated. What would be the impact on her stroke volume, heart rate and mean arterial pressure?

While riding a bicycle up A Mountain, you experience significantly increased venous return. What would be the impact on your stroke volume, heart rate and mean arterial pressure?

After being shot multiple times while robbing the Circle K, Thelma is losing a lot of blood. What would be the impact on her stroke volume, heart rate and mean arterial pressure?

Answer 1

Alexandra is badly dehydrated. Due to dehydration the blood volume decreases and since blood volume decreases, the stroke volume also decreases. Decrease in blood volume also decreases the blood pressure and since blood pressure decreases the mean arterial pressure also decreases as mean arterial pressure is dependent upon systolic and diastolic pressure. To compensate this decreased blood volume and blood pressure the heart beats fast which increases the heart rate to pump more blood out of the heart per minute. Hence there will be decreased stroke volume, decreased mean arterial pressure and increased heart rate in Alexandra due to dehydration.