Question

Select the correct statements about the heart.

• A. Blood flows at tremendous pressure through the heart, so valves are absent.
• B. Deoxygenated blood flows on the right side and oxygenated blood flows on the left side.
• C. The atrium and the ventricle on the right side contract simultaneously, and the atrium and the ventricle on the left side contract simultaneously.
• D. The two atria contract simultaneously, and the two ventricles contract simultaneously.

Answer 1

Answer: (B), (D)

The correct options are
B Deoxygenated blood flows on the right side and oxygenated blood flows on the left side.
D The two atria contract simultaneously, and the two ventricles contract simultaneously.

Deoxygenated blood flows on the right side and oxygenated blood flows on the left side. Blood flows into the atria. When the atria are filled, they contract simultaneously. The blood then flows to the ventricles, which then contract simultaneously. Valves are present between the atria and ventricles that prevent the backflow of blood when the ventricles contract and relax.