B2.10 The Circulatory system

• The three parts of the circulatory system are the blood, the blood vessels, and the heart.
• A, C

  
• Right Atrium

  
• On each side of the heart, the atrium and ventricle are separated by a valve, which prevents the blood from flowing backwards.
• Left ventricle

  
• The _______ ventricle has thicker walls because it has to pump blood all the way around the body.

  left
• Which blood vessel carries deoxygenated blood from the heart to the lungs?

  Pulmonary artery
• The journey of blood around the body

  Body tissues ➔ vena cava ➔ right atrium ➔ right ventricle ➔ pulmonary artery ➔ lungs ➔ pulmonary vein ➔ left atrium ➔ left ventricle ➔ aorta ➔ body tissues
• Which blood vessel carries oxygenated blood from the heart to the body?

  Aorta
• The movement of blood between the ventricles and atria: 

  • The walls of the atria contract, pushing blood into the relaxed ventricles.
  • The walls of the ventricles contract, pushing blood out of the heart.
  • At the same time, more blood will enter the now-relaxed atria.
  • The cycle repeats
• Pacemaker cells are found in which chamber of the heart?

  Right atrium
• The coronary arteries supply the heart muscle with oxygen and nutrients.
• 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 path blood takes 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
• How many times does the heart cycle in a minute?

  About 70 times
• What cells act as a pacemaker in the heart?

  Pacemaker cells in the right atrium
• What do pacemaker cells produce?

  Electrical impulses
• What is an artificial pacemaker?

  A device that regulates heart contractions
• What does the term artery refer to?

  Any vessel carrying blood away from the heart
• What does the term vein refer to?

  Any 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
• What is the total number of times the heart beats in a day?

  Over 100,000 times
• What happens when pacemaker cells malfunction?

  Doctors can implant an artificial pacemaker
• How does the structure of the heart support its function?

  Thick walls and valves ensure efficient blood flow