In a natural cycle, fertilisation of the human oocyte most commonly occurs in which anatomical site?
- A Ampulla of the fallopian tube ✓
- B Isthmus of the fallopian tube
- C Uterine cavity at the fundus
- D Ovarian surface just after follicular rupture
Correct answer: A. Ampulla of the fallopian tube
Explanation
The ovulated oocyte is picked up by the fimbriae and fertilisation normally occurs in the ampulla, the widest and longest portion of the tube. The isthmus acts as a sperm reservoir and regulates transport, but it is not the usual site of gamete fusion. Implantation, not fertilisation, occurs in the uterine cavity, typically six to seven days after fertilisation at the upper posterior uterine wall.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.