QHS Patient Education Topics

The heart consists of four chambers: two atria (upper chambers) and two ventricles (lower chambers). The ventricles are the main pumping chambers responsible for pushing blood out of the heart and into the circulatory system. The right ventricle pumps oxygen-poor blood to the lungs for oxygenation, while the left ventricle pumps oxygen-rich blood to the rest of the body. The walls of the left ventricle are thicker and stronger than those of the right ventricle, reflecting the greater force needed to pump blood throughout the body.

The heart has four valves that ensure blood flows in the right direction and prevents backflow. The tricuspid valve separates the right atrium from the right ventricle, while the mitral valve separates the left atrium from the left ventricle. These valves open and close in coordination with the heart’s pumping cycle to allow blood to move forward efficiently. The pulmonary valve and aortic valve control blood flow out of the right ventricle into the lungs and out of the left ventricle into the body, respectively.

The coronary arteries supply the heart muscle (myocardium) with oxygen-rich blood, ensuring the heart can function properly. The left coronary artery branches into the left anterior descending artery and the circumflex artery, providing oxygenated blood to the left side of the heart. The right coronary artery supplies the right side of the heart. These arteries wrap around the heart, delivering oxygen and nutrients to the myocardium while removing waste products.

The heart’s conduction system coordinates the heartbeat by generating and transmitting electrical impulses. It includes the sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, and Purkinje fibers. The SA node, located in the right atrium, initiates the heartbeat by sending electrical signals that cause the atria to contract. The AV node delays the signal briefly to allow the ventricles to fill with blood before contracting. The bundle of His and Purkinje fibers then transmit the signal to the ventricles, causing them to contract and pump blood out of the heart.

Understanding the intricate workings of the heart, including its ventricles, valves, coronary arteries, and conduction system, is vital for appreciating the complexity of this vital organ and maintaining optimal heart health.