GCSE Biology

• What is the role of the circulatory system?

  To transport oxygen and nutrients to the body's tissues
• What are the three main components of the circulatory system?

  The blood, blood vessels, and heart
• How does the heart function in the circulatory system?

  The heart pumps blood to keep it moving through the blood vessels
• What is the structure of the circulatory system?

  • Composed of the heart, blood vessels, and blood
  • Functions as a double circulatory system with two loops:

  1. Deoxygenated blood to lungs for oxygenation
  2. Oxygenated blood to the body
• How many chambers does the heart have?

  Four chambers
• What are the names of the top and bottom chambers of the heart?

  The top chambers are called atria and the bottom chambers are called ventricles
• What prevents blood from flowing backwards in the heart?

  Valves
• Describe the path blood takes through the heart.

  1. Blood enters via the vena cava and pulmonary vein
  2. Flows into the right atrium (deoxygenated) and left atrium (oxygenated)
  3. Atria contract, pushing blood into ventricles
  4. Ventricles contract, sending blood into pulmonary artery and aorta
  5. Cycle repeats
• How many times does the heart cycle in a minute?

  About 70 times a minute
• What is the function of the pacemaker cells in the heart?

  They produce electrical impulses that cause the heart to contract
• What is an artificial pacemaker used for?

  To regulate the heart's rhythm when pacemaker cells do not function properly
• What is the difference between arteries and veins?

  Arteries carry blood away from the heart, while veins carry blood to the heart
• Can arteries carry deoxygenated blood?

  Yes, for example, the pulmonary artery carries deoxygenated blood
• Can veins carry oxygenated blood?

  Yes, for example, the pulmonary vein carries oxygenated blood
• What are coronary arteries and their function?

  • Small arteries that branch off the aorta
  • Supply oxygenated blood to the heart muscle
  • Ensure the heart muscle receives necessary nutrients
• What is the purpose of the coronary arteries?

  To supply oxygenated blood to the heart muscle
• What are the three main types of blood vessels discussed in the video?

  Arteries, capillaries, and veins
• What is the primary function of arteries?

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

  To exchange nutrients and oxygen with tissues
• What do veins do in the circulatory system?

  They carry blood back to the heart
• How does the structure of arteries relate to their function?

  Arteries have thick walls with muscle and elastic tissue to withstand high pressure
• Why do arteries need to be strong and elastic?

  To bear the high pressures of blood pumped from the heart
• What is the lumen of a blood vessel?


  The hole or space in the middle of the vessel
• How are capillaries adapted for their function?

  They have walls that are only a single cell thick and are permeable
• Why is the total cross-sectional area of capillaries larger than that of arteries?

  Because there are many capillaries, which allows for lower blood pressure and slower flow
• What is the pressure of blood in capillaries compared to arteries?

  The pressure is much lower in capillaries than in arteries
• What is the primary function of veins?

  To transport blood back to the heart
• Why do veins have valves?

  To prevent blood from flowing backwards
• How do you calculate the rate of blood flow?

  By dividing the volume of blood by the time it took to flow
• If 2500 ml of blood passes through the aorta in 8 minutes, what is the rate of blood flow?

  $320 \text{ ml/min}$
• What are the structural differences between arteries, capillaries, and veins?

  • Arteries: Thick walls, strong and elastic, small lumen
  • Capillaries: Single cell thick walls, permeable, tiny lumen
  • Veins: Thin walls, large lumen, valves present
• What are the key functions of the three types of blood vessels?

  • Arteries: Carry blood away from the heart
  • Capillaries: Exchange nutrients and waste with tissues
  • Veins: Return blood to the heart