The essentials
Behind the breastbone, tilted to the left, between the two lungs.
- Size
- About the size of your fist
- Weight
- 250 to 350 g
- Daily
- Beats about 100,000 times
- Location
- Behind the sternum, slightly left
- Blood supply
- Left and right coronary arteries
- Function
- Pumps blood to the lungs and body
Read all anatomy notes · 13
Aorta
Carries oxygen-rich blood from the left ventricle to the whole body.
Superior vena cava
Returns oxygen-poor blood from the head and arms to the right atrium.
Right atrium
Receives blood from the body before it goes to the lungs.
Left ventricle
The thickest chamber; it pushes blood into the aorta under pressure.
Pulmonary trunk
Leaves the right ventricle and splits toward each lung.
Left atrium
Receives oxygenated blood from the pulmonary veins and passes it to the left ventricle.
Right ventricle
Pumps blood to the lungs through the pulmonary trunk.
Posterior mitral leaflet
The mitral valve separates the left atrium and ventricle and prevents backflow during ventricular contraction. Only one of its two leaflets is represented here.
Aortic valve
Its three cusps separate the left ventricle from the aorta. They close to prevent blood flowing back into the ventricle.
Great cardiac vein
Runs alongside the anterior interventricular artery, then reaches the coronary sinus. It drains blood from part of the heart muscle.
Anterior interventricular artery
A branch of the left coronary artery. It follows the groove between the ventricles and supplies the anterior wall and part of the septum.
Right coronary artery
Follows the groove between the right atrium and ventricle. It supplies oxygen to part of the heart muscle.
Coronary sinus
A venous collector on the back of the heart. It receives several cardiac veins and empties into the right atrium.