The Heart and Circulation

• What is the primary function of the heart?

  To pump blood around the body
• What are the two types of circulatory systems mentioned?

  • Single circulatory system (e.g., fish)
  • Double circulatory system (e.g., humans)
• How does the single circulatory system in fish work?

  Deoxygenated blood is pumped to the gills, becomes oxygenated, and then goes to the organs.
• What is a disadvantage of the single circulatory system?

  It loses pressure, causing slower blood travel to the organs and less oxygen delivery.
• How does the double circulatory system in humans differ from the single circulatory system?

  Blood passes through the heart twice, enabling rapid oxygen delivery to body cells.
• What are the four chambers of the human heart?

  • Left atrium
  • Right atrium
  • Left ventricle
  • Right ventricle
• What separates the atria from the ventricles in the heart?

  Valves
• What is the function of the vena cava?

  To bring oxygenated blood from the body to the heart
• What is the role of the pulmonary artery?

  To carry deoxygenated blood from the heart to the lungs
• What does the pulmonary vein do?

  It carries oxygenated blood from the lungs to the heart
• What is the function of the aorta?

  To pump oxygenated blood from the heart to the body
• Describe the pattern of blood flow through the heart.

  1. Blood enters the left and right atria
  2. Atria contract, forcing blood into the ventricles
  3. Ventricles contract, pumping blood out of the heart
  4. Valves prevent backflow into the atria
• Why does the left ventricle have a thicker muscular wall than the right ventricle?

  Because it pumps blood around the entire body, needing greater force.
• What is the purpose of the coronary arteries?

  To supply oxygen to the muscle cells of the heart
• What is the role of oxygen in the heart muscle cells?

  It is used in respiration to provide energy for contraction
• What controls the natural resting heart rate?

  A group of cells in the right atrium called the pacemaker
• What is an artificial pacemaker?

  It is a device that corrects irregular heart rates.
• What should you be able to describe after this lesson?

  • The structure of the heart
  • How the heart pumps blood around the body