Hollow, muscular, four-chambered (left and right atria, and left and right ventricles) organ located in the middle of the thoracic cavity between the lungs in the space called the mediastinum
The heart is about the size of a clenched fist and weighs approximately 255 g (9 oz) in women and 310 g (10.9 oz) in men
Heart location
Extends vertically from the left second to the left fifth intercostal space (ICS) and horizontally from the right edge of the sternum to the left midclavicular line (MCL)
Heart shape
Can be described as an invertedcone, with the upper portion (near the left second ICS) as the base and the lower portion (near the left fifth ICS and the left MCL) as the apex
Precordium
The anterior chest area that overlies the heart and great vessels
Pulmonary circulation
The right side of the heart pumps blood to the lungs for gas exchange
Systemic circulation
The left side of the heart pumps blood to all other parts of the body
Great vessels
The large veins and arteries leading directly to and away from the heart
Great vessels
Superior vena cava
Inferior vena cava
Pulmonary artery
Pulmonary veins
Aorta
Superior vena cava
Returns blood to the right atrium from the upper torso
Inferior vena cava
Returns blood to the right atrium from the lower torso
Pulmonary artery
Exits the right ventricle, bifurcates, and carries blood to the lungs
Pulmonary veins
Return oxygenated blood to the left atrium (two from each lung)
Aorta
Transports oxygenated blood from the left ventricle to the body
