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
• What is the structure of the heart?

  • Four chambers: two atria and two ventricles
  • Thick muscular walls
  • Valves between chambers and vessels
• How does the heart function in the circulatory system?

  It pumps blood to keep it moving
• How many chambers does the heart have?

  Four chambers
• What is the individual chamber of an atrium called?

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

  Atria
• 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, pushing blood into pulmonary artery and aorta
  5. Cycle repeats
• How many times does the heart cycle in a minute?

  About 70 times
• What do pacemaker cells do?

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

  To regulate heart contractions
• What does the term artery refer to?

  Any vessel carrying blood away from the heart
• What prevents blood from flowing backwards in the heart?

  Valves
• What is the difference between arteries and veins?

  Arteries carry blood away; veins carry blood to
• What does the pulmonary artery carry?

  Deoxygenated blood away from the heart
• What does the pulmonary vein carry?

  Oxygenated blood to the heart
• How does the heart receive its own blood supply?

  • Through coronary arteries
  • Branch off the aorta
  • Supply oxygen and nutrients to heart muscle
• What do coronary arteries do?

  Supply oxygenated blood to the heart
• Why is it important for the heart to have its own blood supply?

  To ensure muscle tissue gets oxygen and nutrients