The human circulatory system can be thought of as a closed system of interconnecting pipes through which fud is continuo

[answerhappygod]

The Human Circulatory System Can Be Thought Of As A Closed System Of Interconnecting Pipes Through Which Fud Is Continuo 1 (37.97 KiB) Viewed 35 times

The human circulatory system can be thought of as a closed system of interconnecting pipes through which fud is continuously circulated by two pumps. The two synchronous pumps, the right and left ventricles of the heart work as simple two-stroke force pumps. The muscles of the heart roguate the force by contracting and relaxing. The contraction (ayntole) lasts about 02 seconds, and a complete systolo/diastole (contraction/relaxation) cycle tants about 0.8 seconds. For blood pressures and speeds in the normal range, the volume flow rate of blood through a blood vessel is directly proportional to the pressure difference over a longth of the vessel and to the fourth power of the radius of the vessel The total mechanical energy per unit volume of blood just as it leaves the heart is: E 1 pgh+ P + 5pu? V The first term on the right side of the equation is the gravitational potential energy per unit volume of blood, where is the density is the acceleration due to gravity, and his the height of the blood with respect to the height of the heart. The second term is the blood pressure just as the blood leaves the heart. The work done by the heart creates the blood pressure. The third term is the kinetic energy per unit volume of blood, where is the velocity of the blood as it leaves the heart. (Note: The density of blood equals 1050 kg/m 3 and the acceleration due to gravity is 9.8 mis 2) Why is diastolic blood pressure much lower than systolic blood pressuro? (Note: A typical systola diastole reading in mmHg is 120/80.) O A. Because the heart exerts no force on the blood during diastole O B. Because the heart exerts more force on the blood during diastole OC. Because the radi of the blood vessels decrease during diastole, while the force exerted by the heart on the blood remains the same OD. Because the radi of the blood vessels increase during diastole, while the force exerted by the heart on the blood remains the same