Lymphatic Capillaries
| Home |Chapter: HAP - Lymphatic System
Lymphatic capillaries are microscopic vessels that form the beginning of the lymphatic system. They are larger in diameter than blood capillaries and have very thin walls, which allow easy entry of tissue fluid.
LYMPHATIC
CAPILLARIES
Lymphatic
capillaries are microscopic vessels that form the beginning of the lymphatic
system. They are larger in diameter than blood capillaries and have very
thin walls, which allow easy entry of tissue fluid.
Lymphatic
capillaries are found throughout the body except in the following areas:
Lymphatic Capillaries not present in:
|
AREA |
REASON |
|
Avascular
tissues |
No
blood supply |
|
Central
nervous system |
Specialized
circulation |
|
Splenic
pulp |
Specialized
lymphoid tissue |
|
Bone
marrow |
Blood
cell formation |
These
capillaries contain specialized one-way valves. These valves allow
interstitial fluid to enter the capillary but prevent it from flowing back
into the tissue space.
Lymphatic
capillaries are made up of endothelial cells. When the pressure of
interstitial fluid increases, it pushes open the valves, allowing fluid to
enter. When pressure normalizes, the valves close, preventing backward flow.
Attached
to lymphatic capillaries are anchoring filaments. These are fine
collagen fibers that connect endothelial cells to surrounding tissues. When
tissues swell or move, anchoring filaments pull the capillaries open, allowing
more fluid to enter.
