The lymphatic endothelium is a specialised form of

epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

, distinct from but similar to vascular endothelium. A

lymph Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to ...

capillary A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...

endothelial cell is distinct from other endothelial cells in that

collagen fiber Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whol ...

s are directly attached to its

plasma membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (t ...

. Although

lymphatic Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to ...

s were first described by

Hippocrates Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of ...

in 400BC and rediscovered as "milky veins in the gut of a well fed dog" in the 17th century by

Gasparo Aselli Gaspare Aselli (or Asellio) ( – 9 September 1625). was an Italian physician noted for the discovery of the lacteal vessels of the lymphatic system. Aselli discovered (or rediscovered) the chylous vessels, and studied systematically the signific ...

, they were ignored for centuries until in 1937

Howard Florey Howard Walter Florey, Baron Florey (24 September 189821 February 1968) was an Australian pharmacologist and pathologist who shared the Nobel Prize in Physiology or Medicine in 1945 with Sir Ernst Chain and Sir Alexander Fleming for his role in ...

showed that lymphatics enlarge in inflammation. At this stage vascular and lymphatic endothelia were seen to be morphologically distinct and lymphatic vessels considered less important. Later it was discovered that VEGF-R3 and

VEGF-C Vascular endothelial growth factor C (VEGF-C) is a protein that is a member of the platelet-derived growth factor / vascular endothelial growth factor (PDGF/VEGF) family. It is encoded in humans by the ''VEGFC'' gene, which is located on chromosom ...

VEGF-D C-fos-induced growth factor (FIGF) (or vascular endothelial growth factor D, VEGF-D) is a vascular endothelial growth factor that in humans is encoded by the ''FIGF'' gene. Function The protein encoded by this gene is a member of the platelet- ...

were the key growth factors controlling lymphatic endothelial proliferation. Markers of lymphatic endolthelium were not discovered until relatively recently. These being LYVE-1 (Jackson et al., 1999) and

podoplanin Podoplanin is a protein that in humans is encoded by the ''PDPN'' gene. Structure and function Podoplanin is a mucin-type protein with a mass of 36- to 43-kDa. It is relatively well conserved between species, with homologues in humans, mice, rat ...

(Kerjaschki, 1999).

See also

References

Further reading