cardiac anatomy 2nd

• Heart


  Organ made up of several tough layers of muscle that pumps blood throughout the body
• Pericardium


  • Thin layer that covers the exterior of the heart
• Endocardium


  • Lines the inside walls of the heart
• Heart chambers


  • Two upper (atrium) and two lower (ventricles)
• Atrium


  Upper chambers that receive blood coming into the heart
• Ventricles


  Lower chambers that pump blood out of the heart
• Heart valves


  • Tricuspid, mitral, pulmonary, and aortic valves that open and close to keep blood moving
• Pumping cycle


  1. Oxygen-depleted blood returns to heart

  2. Enters right atrium

  3. Flows to right ventricle

  4. Pumped to lungs via pulmonary arteries

  5. Oxygen-rich blood returns to left atrium

  6. Goes to left ventricle

  7. Pumped throughout body via aorta
• The heart beats 100,000 times a day, 40 million times a year, and up to 3 billion times over an average lifespan
• Conditions that can disrupt a normal heartbeat


  Myocardial infarction (heart attack), heart disease, hypertension
• Circulatory system


  • Network of veins, arteries, and capillaries spanning over 60,000 miles throughout the body