Ischiocavernosus muscle

The ischiocavernosus is a paired superficial perineal muscle located in the urogenital triangle. It covers the crus of the penis in males and the crus of the clitoris in females. This muscle plays an important role in sexual function by compressing the underlying erectile tissue to maintain engorgement. It is one of the components of the superficial perineal pouch and is innervated by the deep branch of the perineal nerve (from the pudendal nerve, S2–S4).

Structure

The ischiocavernosus is a narrow, elongated skeletal muscle with striated fibers. It arises from the ischial tuberosity and ischial ramus and extends anteriorly to overlie the erectile bodies of the genitalia.

Origin and Insertion

• Origin: Ischial tuberosity and ischiopubic ramus
• Insertion (male): Crus of penis and tunica albuginea of the corpus cavernosum
• Insertion (female): Crus of clitoris

Fascial Coverage

• Invested in Gallaudet's (deep perineal) fascia
• Located superficial to the perineal membrane

Location

The ischiocavernosus lies within the superficial perineal pouch of the urogenital triangle and is situated laterally along the pubic arch. It is more prominent in males due to the size of the erectile structures it overlays.

Function

• Male:
  • Compresses crus of penis to restrict venous outflow
  • Maintains erection of penis during sexual arousal
• Female:
  • Compresses crus of clitoris
  • Assists in clitoral erection

Innervation

• Deep branch of perineal nerve (from pudendal nerve, S2–S4)

Blood Supply

• Perineal branches of the internal pudendal artery

Clinical Significance

• Sexual dysfunction: Weakness of ischiocavernosus may contribute to erectile dysfunction
• Perineal repair: Important to identify and preserve during reconstructive or trauma surgeries
• Muscle training: May be targeted in pelvic floor therapy to improve sexual function