Which part of the uterine tube is closest to the uterus?

• A. Infundibulum
• B. Ampulla
• C. Isthmus
• D. Fimbriae

Answer: (C)

Segments of the uterine tube are arranged from the uterus outward in a specific order, and the one nearest the uterus is the isthmus. This proximal portion forms the connection to the uterine side, has a relatively narrow lumen and thicker muscular wall to help move gametes toward the uterus. The other parts lie further away toward the ovarian end: the infundibulum is the funnel-shaped end with fimbriae that sweep up the oocyte, and the ampulla is the wider, middle portion where fertilization commonly occurs. So, the isthmus is the section closest to the uterus because it sits just outside the uterine wall and leads into the proximal part of the tube.