The thick-walled segment that enters the horn of the uterus is the

The thick-walled segment that enters the horn of the uterus is the

• A. Isthmus
• B. Infundibulum
• C. Ampulla
• D. Interstitial portion

Answer: (A)

The part of the fallopian tube that actually enters the uterine horn is the interstitial (intramural) portion. This segment runs through the myometrium and opens into the uterine cavity at the cornu, so it is the thick-walled portion that connects the tube to the horn. The infundibulum is the funnel-shaped end near the ovary with fimbriae; the ampulla is the wider middle section where fertilization often occurs; and the isthmus is a narrow, thick-walled segment approaching the uterus but does not pass through the uterine wall into the horn.

The part of the fallopian tube that actually enters the uterine horn is the interstitial (intramural) portion. This segment runs through the myometrium and opens into the uterine cavity at the cornu, so it is the thick-walled portion that connects the tube to the horn. The infundibulum is the funnel-shaped end near the ovary with fimbriae; the ampulla is the wider middle section where fertilization often occurs; and the isthmus is a narrow, thick-walled segment approaching the uterus but does not pass through the uterine wall into the horn.