Question

Trace a drop of blood through the mammalian heart (begin at vena cavae and end with aorta). Include all vessels and valves through which it must pass. Which valves are open and which are closed during the different phases of the cardiac cycle?

Answer 1

Blood enters the right atrium from the venae cavae, flows through the open tricuspid valve to the right ventricle, is pumped into the pulmonary arteries, returns as oxygenated blood to the left atrium via pulmonary veins, passes through the open mitral valve to the left ventricle, and is finally ejected through the aorta during systole.

Step-by-step explanation:

Tracing the path of a drop of blood through the mammalian heart starting from the vena cavae and ending with the aorta involves following the blood through various vessels and heart chambers, including valves that open and close during different phases of the cardiac cycle. Initially, in diastole, the right atrium receives deoxygenated blood from the body through the superior and inferior venae cavae. The tricuspid valve is open, allowing blood to flow into the right ventricle.

During ventricular systole, the tricuspid valve closes to prevent backflow, and the pulmonary valve opens, permitting blood to be propelled into the pulmonary arteries and then to the lungs for oxygenation. Blood returns to the heart through the pulmonary veins into the left atrium. The mitral valve, which is open during diastole, allows blood to enter the left ventricle.