the lungs and the heart

Cards (4)

  • the alveoli are surrounded by capillaries
  • oxygen diffuses from the air into the bloodstream through the walls of the alveoli, while carbon dioxide moves out of the bloodstream and into the alveoli.
  • The circulatory system is made up of of the heart, blood vessels and blood.
  • the circulatory system is made up of the heart, blood vessels and blood