Which two muscles join the external anal sphincter in attaching centrally to the perineal body?

Which two muscles join the external anal sphincter in attaching centrally to the perineal body?

• A. Superficial transverse perineal and bulbospongiosus
• B. Bulbospongiosus and ischiocavernosus
• C. Superficial transverse perineal and ischiocavernosus
• D. All three

Answer: (A)

The perineal body is a central anchoring point where several pelvic floor muscles converge to stabilize the anal canal. The external anal sphincter attaches centrally to this structure, and two muscles extend to join it there: the superficial transverse perineal muscle, which originates from the ischiopubic ramus and inserts into the perineal body, and the bulbospongiosus, which also attaches to the perineal body and blends with the sphincter fibers near the midline. The ischiocavernosus does not attach to the perineal body; it runs to the crus of the penis or clitoris rather than to this central tendon. So the muscles that join the external anal sphincter at the perineal body are the superficial transverse perineal and bulbospongiosus.

The perineal body is a central anchoring point where several pelvic floor muscles converge to stabilize the anal canal. The external anal sphincter attaches centrally to this structure, and two muscles extend to join it there: the superficial transverse perineal muscle, which originates from the ischiopubic ramus and inserts into the perineal body, and the bulbospongiosus, which also attaches to the perineal body and blends with the sphincter fibers near the midline. The ischiocavernosus does not attach to the perineal body; it runs to the crus of the penis or clitoris rather than to this central tendon. So the muscles that join the external anal sphincter at the perineal body are the superficial transverse perineal and bulbospongiosus.