The New International Encyclopædia/Anastomosis

ANAS′TOMO′SIS (Gk. ἀναστόμωσις, an opening of the mouth, from ἀνἀ, ana, again + στόμα, stoma, mouth). An anatomical term used to express the union of the vessels which carry blood or other fluids, and also, for convenience’ sake, the junction of nerves. The veins and

Arteries Anastomosing.

lymphatics anastomose to form large single trunks as they approach their ultimate destinations. The arteries break up into small branches, for the supply of the tissues, and each small vessel again communicates with others given off above and below. At each large joint there is a very free anastomosis, so that the safety of the limb beyond may not be entirely dependent on the single arterial trunk passing into it, exposed as it is to all the obstructive influences of the different motions of the limb. After the main artery has been permanently obstructed, the anastomosing vessels enlarge, so as to compensate for the loss; but after a time, only those whose course most resembles the parent trunk continue enlarged, and the others gradually regain their ordinary dimensions.