CAPILLARIES

Annotations:

• Arteries branch into arterioles which further branch into capillaries. From the capillaries the blood reaches the tissues.

1. form a network throughout every tissue in the body except the cornea and cartilage.
   1. CAPILLARY BEDS
2. walls are extremely thin
   1. single layer of endothelial cells
      1. enough for one RBC at a time to squeeze through
3. tiny gaps between the individual cells that form the epitheliuem
   1. allows some components of blood to seep through
      1. These form tissue fluid
4. Blood loses a great deal of it's original pressure by the time it reaches capillaries
   1. when it enters the capillaries, the blood pressure is around 35mm Hg
   2. by the time it reaches the far end of the capillary the blood pressure will have dropped to 10 mm Hg