3b - Lymphatics Flashcards
Unidirectional lymphatic vascular system consists of:
-lymphatic capillaries
-collecting lymphatic vessels
-lymph nodes
-thoracic duct and right lymphatic trunk
Lymphatic capillaries absorb:
-interstitial solutes
-macromolecules
-immune cells that extravasate from the blood vascular system
Lymph formation is facilitated by:
-discontinuous basement membrane
-button-like endothelial junctions
>allow passive paracellular flow
Collecting lymphatic vessels contain:
-zipper like junctions
-lymphatic valves
-contractile smooth muscle cells=enables unidirectional propulsion of lymph
Organization of a lymph node:
-afferent vessels
-a single efferent lymphatic vessel
Lymph drains into venous circulation through 4 lymphovenous valves:
-where the internal jugular vein and external jugular vein drain into subclavian vein
Forces that tend to move fluid outward on arterial side of a capillary:
-capillary pressure
-negative interstitial free fluid pressure
-interstitial fluid colloid osmotic pressure
*net OUTWARD force
Forces that tend to move fluid inward on arterial side of a capillary:
-plasma colloid osmotic pressure
Forces that tend to move fluid outward on venous side of a capillary:
-capillary pressure (less than at arterial side)
-negative interstitial free fluid pressure
-interstitial fluid colloid osmotic pressure
Forces that tend to move fluid inward on venous side of a capillary:
-plasma colloid osmotic pressure
*net INWARD force (due to capillary pressure being lower on venous side)
Lymphatics is the net movement of:
-fluid out of capillaries that needs to re-enter circulation
*creates negative interstitial pressure
What do lymphatics drain from tissues?:
-fluid
-proteins (high MW proteins)
-fats
Lymph flow is related directly to interstitial pressure and increases with:
-increased capillary permeability
-elevated capillary hydrostatic pressure
-decreased plasma colloid pressure
*elevated interstitial pressure
-lymph pump
-skeletal muscle pump
