This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
Pa of the fallopian tube that acts as functional/anatomical sphincter 
Select and explain. 
A. Intramural, B. Isthmus, C. Amphulla, D. Infundibulum
A: Intramural
Answer: A: Intramural 
Explanation: Fallopian tube has 5 pas (lateral to medial); Fimbriae: Finger-like, ciliated projections which capture the ovum from the surface of the ovary. Infundibulum: Funnel-shaped opening near the ovary to which fimbriae are attached. Ampulla: Widest section of the uterine tubes. Feilization usually occurs here. Isthmus: Narrow section of the uterine tubes connecting the ampulla to the uterine cavity Interstitial (also known as intramural) pa that transverses the uterine musculature ref - BDC 6e vol2 pg385