Ischiocavernosus muscle

Where is it located and which layer does it belong to?

This muscle is part of the pelvic floor, which is formed by the perineal muscles and conventionally divided into three layers.

The ischiocavernosus muscle (m. ischiocavernosus) is part of the superficial layer of the urogenital region muscles, located beneath the skin and superficial fascia. Topographically, it is situated laterally along the inferomedial margins of the puboischiatic rami of the hip bone.

The fascia forms sheaths for three superficial muscles: medially lies the bulbospongiosus muscle (m. bulbospongiosus), laterally — the ischiocavernosus muscle (m. ischiocavernosus), and posteriorly — the superficial transverse perineal muscle (m. transversus perinei superficialis). The tendons of the superficial muscle layer join in the midline at the perineal body (centrum tendineum perinei).

Topographical features in males

In men, the ischiocavernosus muscle is associated with the structures of the penis (penis).

It covers the initial parts of the two corpora cavernosa (corpus cavernosum penis) — the crura of the penis (crura penis). These crura attach to the inferior rami of the pubis and ischium.

The corpora cavernosa are surrounded by the tunica albuginea (tunica albuginea). The fascia of the penis (fascia penis) is a continuation of the proper fascia of the perineum and covers the bodies superficial to the tunica albuginea.

Topographical features in females

In women, the topography of m. ischiocavernosus involves the crura of the clitoris (crura clitoridis).

In the chapter on the female perineum, the ischiocavernosus muscle is described as a muscle that originates from the ischium and covers the skin of the clitoris.

In the superficial layer, the bulbospongiosus muscle (m. bulbospongiosus) is located medially. In women, deep to each such muscle lies the vestibular bulb (bulbus vestibuli) — a robust venous plexus, homologous to the bulb of the penis in males.

Adjacent structures of the urogenital region

The same fragments of the superficial layer and urogenital diaphragm indicate:

• Bulbospongiosus muscle (m. bulbospongiosus) — located medially in the superficial layer. In men, it covers the bulb of the penis; in women, the vestibular bulb lies deep to it.
• Superficial transverse perineal muscle (m. transversus perinei superficialis) — located posteriorly and runs from the ischial tuberosity to the perineal body.
• Urogenital diaphragm (diaphragma urogenitale) — located beneath the first layer of muscles, forming the middle layer. It represents fused fascial layers stretched between the pubic bones; it includes the deep transverse perineal muscle (m. transversus perinei profundus).

Class and exam questions

What else to study on this topic

• Corpus cavernosum of the penis
• Bulbospongiosus muscle (m. bulbospongiosus)
• Urogenital diaphragm
• Superficial transverse perineal muscle

Other topics in the "Anatomical Structures" section

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