external anal sphincter

Structure

3 parts:

• subcutaneous
• superficial
• deep (intermingles with the puborectalis muscle posteriorly)

Origin

• Skin & fascia surrounding anus & coccyx via anococcygeal ligament

Insertion

• Perineal body

Innervation

• Inferior anal nerve Main action:
• Closes anal canal
• Works with bulbospongiosus to support & fix perineal body

More general terms

• skeletal muscle (voluntary muscle)

Additional terms

• anal sphincter
• perineum