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11. Which of the following will increase mean circulatory pressure? a. a decreas

ID: 3514202 • Letter: 1

Question

11. Which of the following will increase mean circulatory pressure? a. a decrease in blood volume b. an increase in total peripheral resistance c. a decrease in the capacitance of the stressed volume d. an increase in the unstressed volume e. a decrease in cardiac contractility 12. Circle the incorrect answer. An increase in venous pressure (preload) will result in an increase in a. shortening velocity b. cardiac muscle fiber length c. pressure during isovolumetric relaxation d. end-diastolic volume e. end-systolic volume 13. Sympathetic stimulation of the heart a. increases the heart rate. b. increases the contractility of the heart. c. shifts the Frank-Starling curve to the left. d. Both (a) and (b) above are correct e. All of the above are correct. 14. Draw a typical ECG signal. If the R-R interval is 800 ms what is the heart rate? If the heart rate is 90 beats/min, what is the cycle length?

Explanation / Answer

C. Decrease in the capacitance of stressed volume

Mean circulatory pressure is a function of volume fluid within the system and capacitance of the system. Decrease in the capacitance of system (due to vessel wall contraction) will increase mean circulatory filling pressure. Where as decrease in the blood volume decreases mean circulatory filling pressure