ANASTOMOSIS, or Anastomoses, in Anatomy, is sometimes used to express such an Opening of the Mouths of the Vessels, as lets out their Contents. See VESSEL, etc. The Word is formed from the Greek ἀναστόμωσις (anastomōsis), from ἀνά (ana, through) and στόμα (stoma, mouth).
Anastomoses are more frequently used to denote the opening of two Vessels into one another; or the Union and Juncture of the Mouths of two Vessels, whereby they come to communicate with one another. There are various Anastomoses of this kind, e.g., of an Artery with an Artery, a Vein with a Vein, or a Vein with an Artery. See ARTERY, and VEIN. The Circulation of the Blood in the Fetus is effected by means of the Anastomoses, or Inosculation of the Vena Cava with the Pulmonary Vein; and of the Pulmonary Artery with the Aorta. See FETUS.
The same Circulation is also performed in Adults, by the Anastomoses or Continuations of the Capillary Arteries with the Veins. See CIRCULATION OF THE BLOOD. After the Circulation of the Blood through the Heart, Lungs, and large Blood-Vessels, was demonstrated by Harvey; it was only guessed how the Extremities of the Arteries transmitted the Blood to the Veins: till Leeuwenhoek’s Microscopes had discovered the Continuations of the Extremities of those Vessels, in Fish, Frogs, etc.—However, there were not wanting those who doubted the like Continuations of the Extremities of the Arteries and Veins in human Bodies and Quadrupeds; since those Animals it had hitherto been chiefly seen in satisfactorily, were either such Fish, or amphibious Kinds, as have but one Ventricle in their Hearts, and their Blood actually cold; beside that their Blood does not circulate with such Rapidity, as in Animals whose Hearts have two Ventricles. This difference in the principal Organs of Circulation, moved Mr. Cowper to make Experiments on Animals, whose Organs differ only from the Human in their gross Figure, and not in their intimate Structure. —The Result was a plain Discovery of the like Continuations of the Arteries and Veins in the Omentum of a Cat. George Frederick Francus, of Frankenau, a Physician of Copenhagen, published, in the Year 1705, a learned and copious Work, titled "Anastomoses Revelatae."
