Your Professor’s stroke volum e at rest is 90 mL (because he has a big heart - believe it or not). His systolic pressure is 135 m m Hg and diastolic is 90 mm Hg. W hen reading your exam s, his systolic pressure climbs to 150 mm Hg while diastolic pressure is unchanged. Assume no change in compliance of his arteries. Your Professor’s stroke volume while reading your exams
A) Increases to about 150 mL B) Increases to about 120 mL C) Decreases to about 60 mL D) Is unchanged E) Can’t be determined because sympathetic stimulation constricts the veins
If the flow through an artery obeys Poiseuille’s law, decreasing the radius of an artery by a factor of 2 should
A) Increase the resistance by a factor of 2 B) Increase the resistance by a factor of 4 C) Increase the resistance by a factor of 8 D) Increase the resistance by a factor of 16 E) Decrease the resistance by a factor of 8