Lymph capillary

Lymph capillary
Diagram showing the formation of lymph from interstitial fluid (labeled here as "Tissue fluid"). Note: how the tissue fluid is entering the blind ends of lymph capillaries (indicated by deep green arrows)
Details
Identifiers
Latin	vas lymphocapillare
Code	TH H3.09.02.0.05004
TA	A12.0.00.044
FMA	5028
*Anatomical terminology* [edit on Wikidata]

Lymph capillaries or lymphatic capillaries are tiny, thin-walled vessels located in the spaces between cells (except in the central nervous system and non-vascular tissues) which serve to drain and process extra-cellular fluid. Upon entering the lumen of a lymphatic capillary, the collected fluid and associated cells (notably white blood cells) is known as lymph. Each lymphatic capillary carries lymph into a lymphatic vessel, which in turn connects to a lymph node. Lymph is ultimately returned to the venous circulation.

Lymphatic capillaries are slightly larger in diameter than blood capillaries, and have closed ends (unlike the loop structure of blood capillaries). Their unique structure permits interstitial fluid to flow into them but not out. The ends of the endothelial cells that make up the wall of a lymphatic capillary overlap. When pressure is greater in the interstitial fluid than in lymph, the cells separate slightly, like the opening of a one-way swinging door, and interstitial fluid enters the lymphatic capillary. When pressure is greater inside the lymphatic capillary, the cells adhere more closely, and lymph cannot escape back into interstitial fluid. Attached to the lymphatic capillaries are anchoring filaments, which contain elastic fibers. They extend out from the lymphatic capillary, attaching lymphatic endothelial cells to surrounding tissues. When excess interstitial fluid accumulates and causes tissue swelling, the anchoring filaments are pulled, making the openings between cells even larger so that more fluid can flow into the lymphatic capillary.^[1]

Lymph capillaries have a greater internal oncotic pressure than blood capillaries, due to the greater concentration of plasma proteins in the lymph.

References

↑ Tortora, Gerard J.: "Principles of Human Anatomy - 10th edition", page 512. John Wiley and Sons, Inc., 2005. lymph enters the lymph capillaries by osmosis

Arteries and veins

Vessels

Arteries	Nutrient artery Arteriole Metarteriole

Capillaries	Types Continuous Fenestrated Sinusoidal Precapillary sphincter Precapillary resistance

Veins	Vena comitans Superficial vein Deep vein Emissary veins Venous plexus Venule

Lymph	Lymphatic vessel Lymph Lymph capillary

Circulation

Systemic	Left heart → Aorta → Arteries → Arterioles → Capillaries → Venules → Veins → Vena cava → (Right heart)

Pulmonary	Right heart → Pulmonary arteries → Lungs → Pulmonary vein → Left heart

Microanatomy

Lymphatic vessels

Nodal	Lymph capillary Lymphatic vessel Afferent lymph vessel Efferent lymph vessel

Other	Lymph trunk Lymph Lymphangion

This article is issued from Wikipedia - version of the 9/9/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.