HEART AND GREAT VESSELS

• Heart

  • 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
  • About the size of a clenched fist
  • Weighs approximately 255 g (9 oz) in women and 310 g (10.9 oz) in men
  • Extends vertically from the left second to the left fifth intercostal space (ICS)
  • Extends horizontally from the right edge of the sternum to the left midclavicular line (MCL)
  • Can be described as an inverted cone
  • Upper portion, near the left second ICS, is the base
  • Lower portion, near the left fifth ICS and the left MCL, is the apex
• Precordium

  The anterior chest area that overlies the heart and great vessels
• Pulmonary circulation

  Right side of the heart pumps blood to the lungs for gas exchange
• Systemic circulation

  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
• Superior and inferior vena cava

  • Return blood to the right atrium from the upper and lower torso, respectively
• Pulmonary artery


  • Exits the right ventricle, bifurcates, and carries blood to the lungs
• Pulmonary veins

  • Two from each lung, return oxygenated blood to the left atrium
• Aorta

  • Transports oxygenated blood from the left ventricle to the body