Longest part of fallopian tube?

Ans. a (ampulla). (Ref. Williams, Obstetrics, 21st ed., 46)FALLOPIAN TUBE# Fallopian tube has following parts;- interstitial/intramural part,- isthmus,- ampulla,- fimbria.# An intermediate zone, the isthmus, 6 mm in length, lies between endometrium of the body and the mucous membram of the cervical canal.# The isthmic portion forms the lower uterine segment in late pregnancy.# Narrowest part of uterine tube is interstitial portion.# The ampulla:- Is the lateral, widest and lowest part of the tube and comprises roughly two-thirds of the tube.- Here the mucosa is arborescent with many complex folds.- Is the most common site of fertilization.- Is the most common site of tubal pregnancy.