Heart 101

The outermost layer of the heart. The coronary arteries run along this layer.

The middle and thickest layer. Made of pure muscle and does the work of contracting. It is the part that is damaged during a heart attack.

The thin innermost layer that lines the hearts' chambers and folds back onto itself to form the heart valves. It is watertight to prevent leakage of blood into the other layers. The cardiac conduction system is found in this layer.

Surrounds the heart in a double-walled sac. Serves as support and protection and anchors the heart to the diaphragm and great vessels. Fluid called pericardial minimizes friction of these layers as they rub against each other with every heartbeat.

Receiving chamber for deoxygenated blood. O2 saturation is only 60-75%. CO2 concentration is high. Delivers blood to the right ventricle.

Pumps blood to the lungs to get O2. Pressure is relatively low and muscle bulk is relatively thin. Only has to transport blood to the lungs.

Receiving chamber for blood returning from lungs. O2 saturation should be at 100%. Delivers blood to left ventricle.

Pumps oxygenated blood to the body. Generates the highest pressures; must pump blood to the whole body and resist against the actual blood pressure. Muscle bulk is 3x more than the right ventricle.

Mescular band of tissue dividing the right/left sides of the heart.

Separates the atria

Separates the ventricles.

Separate a ventricle from an artery and have 3 half-moon-shaped cusps.

This valve is located between the right ventricle and the pulmonary artery. One of the Semilunar valves

This valve is located between the left ventricle and the aorta. One of the Semilunar valves

Located between an atrium and a ventricle. Supported by Chordae tendineae (tendinous cords), which are attached to papillary muscles and anchor the valve cusps to keep the closed AV valves from flopping backwards (preventing backflow of blood)

Located between the right atrium and ventricle, has three cusps. An atrioventricular valve

Also called Bicuspid valve, located between the left atrium and ventricle. It has 2 Cusps. An atrioventricular valve

reflects the closure of the mitral and tricuspid valve.

reflects the closure of the aortic and pulmonic valves.

Between S1 and S2 the heart beats and expels blood

Between S2 and the next S1 the heart rests and fills with blood.

Large vein that returns deoxygenated blood to the right atrium from the head, neck, and upper chest and arms

Large vein that returns deoxygenated blood to the right atrium from the lower chest, abdomen and legs.

Large artery that takes deoxygenated blood from the right ventricle to the lungs to load up on oxygen and unload carbon dioxide. It is the ONLY artery that carries deoxygenated blood.

The largest artery in the body. Takes oxygenated blood from the left ventricle to the systemic circulation to feed all the organs of the body.

Superior or Inferior vena cava > right atrium > trucuspid valve > right ventricle > pulmonic valve >> pulmonary artery >> lungs >> pulmonary veins >> left atrium >> mitral (bicuspid) valve >> left centricle >> aortic valve >> aorta >> Body