Biology Quiz On Heart Functions! Quiz

The atrioventricular valves and semilunar valves are responsible for controlling the direction of blood flow in the body. The atrioventricular valves, including the tricuspid valve and the mitral valve, separate the atria from the ventricles and prevent blood from flowing back into the atria when the ventricles contract. On the other hand, the semilunar valves, including the aortic valve and the pulmonary valve, are located at the exit of the ventricles and prevent blood from flowing back into the ventricles when they relax. Therefore, it is true that the direction of blood flow is controlled by these valves.

The statement is true because coronary arteries are responsible for supplying the heart muscle with oxygen and nutrients. These arteries branch off from the aorta and wrap around the heart, ensuring that the heart receives the necessary blood flow to function properly. Without adequate oxygen and nutrients, the heart muscle would not be able to contract effectively, leading to various heart-related issues. Therefore, the statement is correct.

The left atrium collects blood from the pulmonary veins. The pulmonary veins carry oxygenated blood from the lungs back to the heart. Once the blood enters the left atrium, it is then pumped into the left ventricle and eventually sent out to the rest of the body through the aorta.

Myogenic muscle contraction refers to the ability of the heart muscle to contract on its own, without the need for external nerve stimulation. The heart has its own internal pacemaker, known as the sinoatrial node, which generates electrical impulses that cause the heart to contract rhythmically. This intrinsic ability of the heart to initiate and coordinate its own contractions is essential for maintaining a steady heartbeat and ensuring proper blood circulation throughout the body.

The right atrium collects blood from the superior and inferior vena cava.