The left ventricle is responsible for pumping oxygenated blood into the systemic circulation through the aorta. The other chambers serve different roles in circulating blood.

The right atrium collects deoxygenated blood from the body via the vena cava. The other chambers have roles related to pumping or receiving blood differently.

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs where it is oxygenated. The other vessels have distinct roles in the circulatory system.

The mitral valve, also known as the bicuspid valve, regulates blood flow from the left atrium to the left ventricle. The other valves are positioned on the right side or manage outflow from the ventricles.

The tricuspid valve regulates the flow of blood from the right atrium to the right ventricle. It is distinct from other valves that manage flow in other regions of the heart.

The aorta is the main artery that carries oxygenated blood from the left ventricle to the systemic circulation. The other vessels have different roles in blood transport.

The atrioventricular (AV) node delays the electrical impulse from the atria to the ventricles, ensuring proper filling before contraction. The other structures have different roles in initiating or conducting electrical signals.

The mitral valve prevents blood from flowing backward from the left ventricle into the left atrium during systole. The other valves regulate flow between other chambers or outflow tracts.

The myocardium is the thick, muscular layer that enables the heart to generate force for blood circulation. The other layers serve as inner lining or protective coverings.

Coronary arteries deliver oxygen-rich blood directly to the myocardium, which is essential for the heart's continuous contraction. Other structures are not directly supplied by these arteries.

Pulmonary veins carry oxygenated blood from the lungs back to the left atrium. The other options describe functions of different vessels.

The aortic valve closes during ventricular diastole to prevent blood from flowing back into the left ventricle. The other valves control blood flow in other parts of the heart.

The Bundle of His carries the impulse from the AV node to the bundle branches and then to the Purkinje fibers in the ventricles. The other structures play different roles in the conduction system.

Systole is the phase when the ventricles contract to pump blood out of the heart. Diastole is the relaxation phase when the heart fills with blood.

The pericardium is a double-layered sac that protects the heart and contains lubricating fluid to reduce friction. The other layers are involved in contraction or form the inner lining of the heart.

The correct sequence starts with deoxygenated blood entering the right atrium, moving to the right ventricle, then to the pulmonary artery, reaching the lungs for oxygenation, and returning via the pulmonary veins to the left atrium before being pumped out through the left ventricle and aorta. The other sequences present incorrect orders.

In cases of AV node failure, the Purkinje fibers can act as an escape pacemaker, maintaining a slow but steady ventricular rhythm. The other options do not serve as a backup pacemaker in such scenarios.

The thick and muscular myocardium of the left ventricle is crucial for generating the high pressures required to pump blood throughout the systemic circulation. The other features do not contribute to high-pressure generation.

The interventricular septum is the muscular wall that separates the left and right ventricles. The interatrial septum divides the atria, while the other structures are components of the great vessels.

Papillary muscles contract during ventricular systole to tense the chordae tendineae, thereby preventing the atrioventricular valves from inverting. This function is critical for maintaining one-way blood flow in the heart.