rafi_mokdadLv1

25 Jan 2023

Problem 4: 40 points

The typical rate at which blood is expelled from the heart is about mL . Blood enters the right half of the heart at a pressure of about 0 Pascal and flows to the lungs at a mean pressure of 1,466 Pascal. Blood returns to the left half of the heat through the pulmonary veins at a mean pressure of 1,067 Pascal. The blood is then discharged from the heart through the aorta at a mean pressure of 12,000 Pascal.

 

 

A. Estimate the total work performed by the heart. Clearly state any assumptions and express your answer in J/kg. (10 points)

 

B. The ascending aorta is approximately 2.6 cm in diameter. The aortic arch is approximately 5 cm above the heart. What is the pressure in the aorta at the beginning of the aortic arch during discharge? (You can assume the blood is experiencing high shear rates.) Clearly state any assumptions. (15 points)

 

C. One of the semilunar valves separates the left ventricle from the aorta. If the pressure in the left ventricle is 91.3 mmHg (12,173 Pascal) during the start of aortic discharge, what is the friction coefficient () for the semilunar valve? Clearly state any assumptions. (15 points)