The Heart and Circulation

• What type of circulatory system do fish have?

  Single circulatory system
• Where does deoxygenated blood go in fish?

  To the gills for oxygenation
• What happens to blood after it collects oxygen in fish?

  It passes to the organs
• What is a disadvantage of a single circulatory system?

  Blood loses pressure before reaching organs
• What type of circulatory system do humans have?

  Double circulatory system
• Where does deoxygenated blood go in humans?

  To the lungs for oxygenation
• What is the benefit of a double circulatory system?

  Blood can travel rapidly to body cells
• How many chambers does the human heart have?

  Four chambers
• What are the names of the upper chambers of the heart?

  Left atrium and right atrium
• What are the names of the lower chambers of the heart?

  Left ventricle and right ventricle
• What separates the atria from the ventricles?

  Valves
• What blood vessel brings deoxygenated blood from the body to the heart?

  Vena cava
• What blood vessel carries blood from the heart to the lungs?

  Pulmonary artery
• What blood vessel carries oxygenated blood from the lungs to the heart?

  Pulmonary vein
• What blood vessel pumps blood from the heart to the body?

  Aorta
• What happens when blood enters the atria?

  The atria contract and force blood into ventricles
• What prevents blood from flowing backwards into the atria?

  Valves in the heart
• Why does the left side of the heart have a thicker muscular wall?

  It pumps blood around the entire body
• What is the function of the coronary arteries?

  To supply oxygen to heart muscle cells
• What do coronary arteries branch out of?

  Aorta
• What is the role of oxygen in heart muscle cells?

  Used in respiration for energy
• What controls the natural resting heart rate?

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

  A group of cells controlling heart rate
• What can doctors implant if the pacemaker fails?

  An artificial pacemaker
• What is an artificial pacemaker?

  A small electrical device
• What is the purpose of an artificial pacemaker?

  To correct irregularities in heart rate
• What is the pattern of blood flow through the heart?

  1. Blood enters the left and right atria.
  2. Atria contract, forcing blood into ventricles.
  3. Ventricles contract, pushing blood out of the heart.
  4. Valves prevent backflow into atria.
• What are the key components of the human heart's structure?

  • Four chambers: left atrium, right atrium, left ventricle, right ventricle
  • Valves separating atria and ventricles
  • Major blood vessels: vena cava, pulmonary artery, pulmonary vein, aorta
  • Thicker muscular wall on the left side
• What are the differences between single and double circulatory systems?

  Single circulatory system:

  • Found in fish
  • Blood passes through the heart once

  
  

  Double circulatory system:

  • Found in humans
  • Blood passes through the heart twice
  • Allows for faster oxygen delivery