capillaries

• What is the diameter of a capillary?


  7 micrometers
• What is the thickness of a capillary?


  1 micrometer- THIN WALLS
• what do capillaries do?


  Capillaries are tiny blood vessels that connect arteries and veins, allowing for the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.
• Why are there gaps between flattened endothelium cells?


  Fenestrations allow for the passage and exit of tissue fluid and gas exchange. this makes the walls LEAKY for blood plasma and substances exiting
• Why do capillaries have a large SA?


  Arranged into capillary beds
• Why does blood flow slowly in the capillaries?


  the diameter of a RBC is the same diameter of the capillary, this slows blood flow so there is enough time for the exchange of gases
• Why is there a short diffusion distance?

  they are one cell thick for efficient gas exchange
• Why do RBC’s squeeze to pass through the capillaries?


  It gives them enough time to give up oxygen