Question
The ischial spine corresponds to which level?
| A. |
S3-S5 |
| B. |
Tip of the coccyx |
| C. | L4 |
| D. |
S2 |
|
Correct Answer » D Explanation |
 |
The ischial spine is a bony projection on the posterior part of the ischium, one of the bones that make up the pelvis. It sits between the greater and lesser sciatic notches, at the level of the lower border of the acetabulum. It serves as an important anatomical landmark in both clinical and surgical settings.
Location: The ischial spine generally corresponds to the S2 vertebral level and serves as an attachment point for the sacrospinous ligament and an important reference in obstetric measurements.
Some fibers of the superior gemellus muscle originate from the upper margin of the lesser sciatic notch and attach to the ischial spine.The posterior fibers of the levator ani, specifically the posterolateral fibers of the iliococcygeus muscle, arise from the pelvic surface of the ischial spine.
The apex of the coccygeus muscle also originates from the ischial spine.
Clinical Significance: The internal pudendal vessels and pudendal nerve wind around the dorsal aspect of the ischial spine before entering the perineum.
