CHAMBERS OF THE HEART

CHAMBERS OF THE HEART

There are four chambers in the heart.the right sided chambers are the right atrium and right ventricles and the left sided are the left atrium and the left ventricle.the right atrium is separated from the left atrium by  a thin membrane called the interatrial septum

Right Atrium

The right atrium receives de-oxygenated blood from the body through the superior vena cava (head and upper body) and inferior vena cava (legs and lower torso). The sinoatrial node sends an impulse that causes the cardiac muscle tissue of the atrium to contract in a coordinated, wave-like manner. The tricuspid valve, which separates the right atrium from the right ventricle, opens to allow the de-oxygenated blood collected in the right atrium to flow into the right ventricle.

Right Ventricle

The right ventricle receives de-oxygenated blood as the right atrium contracts. The pulmonary valve leading into the pulmonary artery is closed, allowing the ventricle to fill with blood. Once the ventricles are full, they contract. As the right ventricle contracts, the tricuspid valve closes and the pulmonary valve opens. The closure of the tricuspid valve prevents blood from leaking back  into the right atrium and the opening of the pulmonary valve allows the blood to flow into the pulmonary artery toward the lungs.

Left Atrium

The left atrium receives oxygenated blood from the lungs through the pulmonary veins. As the contraction triggered by the electrical impulse from sinoatrial node progresses through the atria, the blood passes through the mitral valve into the left ventricle.

Left Ventricle

The left ventricle receives oxygenated blood as the left atrium contracts. The blood passes through the mitral valve into the left ventricle. The aortic valve leading into the aorta is closed, allowing the ventricle to fill with blood. Once the ventricles are full, they contract. As the left ventricle contracts, the mitral valve closes and the aortic valve opens. The closure of the mitral valve prevents blood from backing into the left atrium and the opening of the aortic valve allows the blood to flow into the aorta and flow throughout the body. This chamber has a much thicker muscular wall than the right ventricle (blood has to travel farther through body) and it forms the apex (tip) of the heart. This chamber pumps blood through the aortic semilunar valve into the aorta.

Papillary Muscles

The papillary muscles attach to the lower portion of the interior wall of the ventricles. They connect to the chordae tendineae, which attach to the tricuspid valve in the right ventricle and the mitral valve in the left ventricle. The contraction of the papillary muscles opens these valves. When the papillary muscles relax, the valves close.

Chordae Tendineae

The chordae tendineae are tendons linking the papillary muscles to the tricuspid valve in the right ventricle and the mitral valve in the left ventricle. As the papillary muscles contract and relax, the chordae tendineae transmit the resulting increase and decrease in tension to the respective valves, causing them to open and close. The chordae tendineae are string-like in appearance and are sometimes referred to as “heart strings.”