The heart

• What is the role of the circulatory system?

  To transport oxygen and nutrients
• What are the three main components of the circulatory system?

  Blood, blood vessels, and heart
• What does blood carry in the circulatory system?

  Oxygen and nutrients
• How does the heart function in the circulatory system?

  It pumps blood to keep it moving
• What is the structure of the heart?

  • Four chambers: two atria and two ventricles
  • Thick muscular walls
  • Valves between chambers and vessels
• How many chambers does the heart have?

  Four chambers
• What are the top chambers of the heart called?

  Atria
• What is the individual top chamber of the heart called?

  Atrium
• What are the bottom chambers of the heart called?

  Ventricles
• What is the function of valves in the heart?

  To prevent blood from flowing backwards
• Describe the blood flow through the heart.

  1. Blood enters via vena cava and pulmonary vein
  2. Flows into right atrium and left atrium
  3. Atria contract, pushing blood into ventricles
  4. Ventricles contract, sending blood to pulmonary artery and aorta
  5. Cycle repeats approximately 70 times a minute
• How many times does the heart cycle in a minute?

  Approximately 70 times
• What is the role of pacemaker cells in the heart?

  To produce electrical impulses for contraction
• What is an artificial pacemaker used for?

  To regulate heart contractions
• What is the definition of an artery?

  A vessel carrying blood away from the heart
• What is the definition of a vein?

  A vessel carrying blood to the heart
• Can arteries carry deoxygenated blood?

  Yes, like the pulmonary artery
• Can veins carry oxygenated blood?

  Yes, like the pulmonary vein
• What are coronary arteries and their function?

  • Small arteries branching off the aorta
  • Supply oxygenated blood to the heart muscle
  • Ensure heart muscle receives nutrients
• What do coronary arteries supply to the heart?

  Oxygenated blood
• Why does the heart need its own supply of blood?

  To receive oxygen and nutrients