Capillaries

• What do arterioles branch into?

  capillaries - the smallest of the blood vessels
• Where are substances exchanged between blood and body tissues?

  at capillaries
• What happens between cells and capillaries?

  Substances (eg glucose and oxygen) are exchanged between cells and capillaries

  • so capillaries are adapted for efficient diffusion
• Where are capillaries ALWAYS FOUND?

  Very near cells in exchange tissues, so there is a short diffusion pathway
• What are the walls of capillaries like?

  Only one cell thick = shortens the diffusion pathway
• Why are there a large number of Capillaries|?

  To increase surface area for exchange
• What are capillary beds?


  Networks of capillaries in tissue
• briefly state the 3 adaptations of capillaries for efficient diffusion?

  Always found very near cells in exchange tissues

  Walls only one cell thick

  Large number of capillaries