Circulatory System 2 - 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?

  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 the heart
• What type of tissue do arteries have to maintain strength?

  Thick layer of muscle tissue
• What type of tissue do arteries have to allow stretching?

  Thick layer of elastic tissue
• What is the lumen of a blood vessel?

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

  Walls are single cell thick and permeable
• What is the total cross-sectional area of capillaries compared to arteries?

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

  Lower pressure allows for substance exchange
• What do veins transport back to the heart?

  Blood
• What is unique about the lumen of veins?

  They have the largest lumens of blood vessels
• Why do veins have relatively thin walls?

  Blood in veins is at low pressures
• What do veins have to prevent blood from flowing backwards?

  Valves
• How do you calculate the rate of blood flow?

  • Divide the volume of blood by time
  • Example: 2500 ml in 8 minutes
  • Rate = $\frac{2500 \text{ ml}}{8 \text{ min}} =$$320 \text{ ml/min}$
• What should you do if you haven't seen the other videos on the heart and blood?

  • Check the links in the description