Blood vessels in the body

Cards (10)

  • Humans have a double circulatory system because blood moves through the heart twice (pulmonary and systemic circulation)
    • Allows lots of oxygenated blood to be transported quickly
  • Pulmonary circulation - The right side of the heart and blood vessels carries deoxygenated blood from your heart to the lungs and back again
  • Systemic circulation - The left side of the heart pumps oxygenated blood to every part of the body that uses oxygen
  • Artery structure:
    • Thick layers of muscle in walls to allow them to stretch to withstand the high blood pressure
    • Elastic fibres to recoil back into their original shape
    • Small lume to help maintain high blood pressure
  • Artery function:
    • Carry blood with high oxygen away from the heart to the organs or body
  • Vein structure:
    • Thinner muscular and elastic walls than arteries because blood is under low pressure
    • Larger lumen as well
    • Valves to prevent back flow of blood
  • Vein function:
    • Carry blood with low oxygen from organs towards the heart
  • Capillary structure:
    • Very thin walls (one cell thick) to make sure there is a short diffusion distance for oxygen
  • Capillary structure:
    • Very narrow lumens which only allow one red blood cell to pass through at a time - slows blood flow to increase the time that oxygen and glucose can diffuse into cells
  • Capillary function:
    • Capillaries connect arteries and veins
    • Found close to all cells where substances easily diffuse between the blood and cells