Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining.
These tubal cilia are essential to the movement of the egg through the tube into the uterus. If the tubal cilia are damaged by infection, the egg may not get 'pushed along' normally but may stay in the tube.
Infection can also cause partial or complete blockage of the tube with scar tissue, physically preventing the egg from getting to the uterus.
Any process (such as infection, endometriosis, tumors, or scar tissue in the pelvis (pelvic adhesions) that cause twisting or chinking of the tube) that damages the Fallopian tube or narrows its diameter increases the chance of an ectopic pregnancy: a pregnancy developing in the Fallopian tube or another abnormal location outside the uterus.
These tubes bear the name of Gabriele Falloppio (also spelled Falloppia), a 16th-century (c. 1523-62) Italian physician and surgeon who was expert in anatomy, physiology and pharmacology. He was an early expert on syphilis and one of the great surgeons of the age. Of the various works by Falloppio only the "Observationes anatomicae", a work of great originality, was published during his lifetime. In it he made a number of contributions to the knowledge of centers of ossification, to the detailed account of muscles, and to the understanding of the vascular system and the kidneys. His description of the uterine tubes was sufficiently accurate that they bear his name. With Vesalius and Eustachi, Fallopio is often seen as one of the three heroes of anatomy. (Historical information based on the Catalog of the Scientific Community of the 16th and 17th Centuries by Richard S Westfall for the Galileo Project.)