The longest portion the fallopian tube is
A. Interstinal portion
B. isthmus
C. Infundibular portion
D. Ampullary portion
Correct Answer: D. Ampullary portion
Explanation: The longest portion of the fallopian tube is the ampulla.
Summary of fallopian tube parts (from uterus outward):
1. Intramural (interstitial)
2. Isthmus
3. Ampulla ← longest and widest section; common site of fertilization
4. Infundibulum (with fimbriae)
So, the ampulla is the longest portion.
Other Options Details :
These terms refer to the anatomical parts of the fallopian tube (uterine tube) in the female reproductive system. Here is a clear description of each:
A. Interstitial (Intramural) Portion
• Also called the uterine portion.
• The narrowest part of the fallopian tube.
• Located within the wall of the uterus (myometrium).
• Connects the uterine cavity to the rest of the tube.
• Approximately 1 cm long and 0.1 mm in diameter.
Clinical note: Interstitial ectopic pregnancies can occur here and are serious due to heavy bleeding.
B. Isthmus
• A narrow, thick-walled, straight portion of the tube.
• Located just after the interstitial part, closer to the uterus.
• About 2–3 cm long.
Functions as a sperm reservoir and assists transport of the fertilized ovum to the uterus.
C. Infundibular Portion
• The lateral funnel-shaped part of the tube.
• Opens into the pelvic cavity.
• Ends in fimbriae (finger-like projections) that help capture the ovulated egg from the ovary.
• The widest opening compared to other parts.
D. Ampullary Portion
• The widest and longest section (about 7–8 cm).
• Highly tortuous region.
• Most common site of fertilization (sperm meets the ovum here).
• Also a common site of ectopic pregnancy.
Summary Table
Portion Structure Key Function Notes
Interstitial (Intramural) Narrow, within uterus Passage to uterus Dangerous ectopic site
Isthmus Narrow, straight, thick wall Sperm reservoir & transport Near uterus
Ampulla Wide and long Fertilization occurs here Common ectopic site
Infundibulum Funnel-shaped Collects ovum via fimbriae Opens to pelvic cavity
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Writer: Vandita Singh, Lucknow (GS India Nursing Group)