Anatomy of the Heart

• Where is the heart located?

  In the thorax between the lungs
• What protects the heart?

  The ribs protect the heart
• What are the two layers of the pericardium?

  • Outer fibrous layer
  • Inner serous pericardium
• What is the function of the fibrous pericardium?

  Prevents overfilling of the heart
• What type of tissue is the fibrous pericardium made of?

  Dense connective tissue
• What does the serous pericardium consist of?

  A double layered serous membrane
• What is the visceral layer of the serous pericardium also known as?

  Epicardium
• What is the pericardial cavity?

  A potential space between layers
• What are the three layers of the heart wall?

  1. Endocardium (INNER)
  2. Myocardium (MIDDLE)
  3. Epicardium (OUTER)
• What are the four chambers of the heart?

  1. Right atrium
  2. Left atrium
  3. Right ventricle
  4. Left ventricle
• What is the function of the fibrous skeleton of the heart?

  Separates the atria from the ventricles electrically
• What do heart valves prevent?

  Backflow of blood
• What are the two types of AV valves?

  1. Tricuspid (RIGHT AV)
  2. Bicuspid or mitral (LEFT AV)
• What are the two types of semilunar valves?

  1. Pulmonary
  2. Aortic
• How are AV valves opened?

  By blood flowing from atria to ventricles
• What anchors the AV valves?

  Chordae tendineae to papillary muscles
• What prevents eversion of the AV valves?

  Contraction of papillary muscles
• When do valves open?

  When ventricular pressure is less than atrial pressure
• What do semilunar valves guard?

  The entrances of the aorta and pulmonary trunk
• How are semilunar valves opened?

  By the force of blood as ventricles contract
• What happens to blood during relaxation of the ventricles?

  Blood flows backwards in the aorta
• What happens to the cusps of the semilunar valves during relaxation?

  They are pushed shut by pooling blood
• What is coronary circulation?

  • Blood delivered to myocardium during ventricular relaxation
  • Involves left and right coronary arteries
• What are the branches of the left coronary artery?

  1. Anterior interventricular
  2. Circumflex
• What are the branches of the right coronary artery?

  1. Marginal artery
  2. Posterior interventricular
• Where do cardiac veins drain into?

  Coronary sinus which empties into the right atrium
• What is angiography used for?

  To examine blood vessels and organs
• What does an electrocardiogram (ECG) measure?

  Electrical activity of the heart
• What are the three shortcuts in foetal circulation?

  1. Foramen ovale
  2. Ductus arteriosus
  3. Ductus venosus
• What is the function of the foramen ovale?

  Connects the right to the left atria
• What does the ductus arteriosus connect?

  Connects the pulmonary trunk to the arch of aorta
• What does the ductus venosus connect?

  Connects umbilical vein to inferior vena cava
• What changes occur at birth regarding circulation?

  1. Newborn takes first breath
  2. Lungs expand, left atrium pressure increases
  3. Blood rushes into pulmonary circulation
  4. Foramen ovale closes to become fossa ovalis
  5. Umbilical vessels close
• What are the adult structures that correspond to foetal structures?

  • Ductus venosus → Ligamentum venosum
  • Foramen ovale → Fossa ovalis
  • Ductus arteriosus → Ligamentum arteriosum