blood vessels

• 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 in this video?

  Arteries, capillaries, and veins
• What is the role of arteries in the circulatory system?


  • Carry blood away from the heart
  • Transport oxygenated blood (except pulmonary arteries)
• What is the role of capillaries in the circulatory system?


  • Exchange nutrients and oxygen with tissues
  • Remove waste products like carbon dioxide
• What is the role of veins in the circulatory system?


  • Carry blood back to the heart
  • Transport deoxygenated blood (except pulmonary veins)
• Why do arteries need to be strong and elastic?


  To withstand high pressures from blood pumped out of the heart
• What structural features help arteries manage high blood pressure?


  Thick layers of muscle and elastic tissue
• 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 a single cell thick and are permeable
• What happens to blood pressure as it moves from arteries to capillaries?


  It decreases
• Why do capillaries have a large total cross-sectional area?


  To allow for lower blood pressure and slower flow for exchange
• What is the primary function of veins?


  To transport blood back to the heart
• What structural features do veins have to assist their function?


  Thin walls, large lumens, and valves
• What is the purpose of valves in veins?


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


  By dividing the volume of blood by the time taken
• 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 key differences between arteries, capillaries, and veins?

  • Arteries: Thick walls, high pressure, carry blood away from the heart
  • Capillaries: Thin walls, low pressure, exchange substances
  • Veins: Thin walls, large lumens, carry blood back to the heart with valves
• What is the largest artery in the body?

  The aorta