Which muscle forms the posterior part of the pelvic diaphragm, arising from the ischial spine and inserting into the lateral margins of the sacrum and coccyx?

• A Puborectalis
• B Iliococcygeus
• C Piriformis
• D Coccygeus ✓

Explanation

The coccygeus (ischiococcygeus) completes the pelvic diaphragm posteriorly, running from the ischial spine to the lateral border of the lower sacrum and coccyx. Puborectalis is the sling around the anorectal junction, iliococcygeus is a part of levator ani arising from the tendinous arch rather than the ischial spine, and piriformis lies on the pelvic wall above the diaphragm, not within it.

Reference: Moore Clinically Oriented Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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