Cardiovascular System

• 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 term for one atria?

  Atrium
• What prevents blood from flowing backwards in the heart?

  Valves
• 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
• How many times does the heart cycle in a minute?

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

  Pacemaker cells
• What do pacemaker cells produce?

  Electrical impulses
• What is an artificial pacemaker used for?

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

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

  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
• What system did we introduce in the last video?

  The circulatory system
• What is the primary function of the heart in the circulatory system?

  It acts as the system's pump
• What are the three types of blood vessels discussed?

  Arteries, capillaries, and veins
• What do arteries do with blood?

  They carry blood away from the heart
• What is the role of capillaries in the circulatory system?

  They exchange nutrients and oxygen with tissues
• How do veins function in the circulatory system?

  They carry blood back to the heart
• How is the structure of arteries related to their function?

  They are strong and elastic to handle high pressure
• Why do arteries have thick walls?

  To withstand high blood pressure
• What is the lumen of a blood vessel?

  The hole or space in the middle
• What is the significance of capillaries being only one cell thick?

  It allows for easy diffusion of substances
• How does the total cross-sectional area of capillaries compare to that of arteries?

  It is much larger than that of arteries
• Why does blood flow more slowly in capillaries?

  Because the total cross-sectional area is huge
• What do veins have that prevents blood from flowing backwards?

  Valves
• Why do veins have thinner walls compared to arteries?

  Because they carry blood at low pressures
• How do you calculate the rate of blood flow?

  Divide volume of blood by time
• If 2500 ml of blood passes in 8 minutes, what is the flow rate?

  320 ml per minute