Bulbocavernosus

Bulbocavernosus

The bulbocavernosus muscle(also known as the bulbospongiosus muscle) is a muscle of the perineum, which is the region of the body located between the pubic symphysis and the coccyx. This muscle plays a crucial role in the function of the pelvic floor and is involved in various physiological processes.

Anatomy

The bulbocavernosus muscle is part of the superficial perineal muscles. It is located in both males and females, although its structure and function differ slightly between the sexes.

In Males

In males, the bulbocavernosus muscle covers the bulb of the penis. It is responsible for compressing the bulb of the penis, which helps in emptying the urethra after urination and during ejaculation. The muscle also contributes to the rigidity of the penis during erection by compressing the deep dorsal vein of the penis.

In Females

In females, the bulbocavernosus muscle is split into two halves that cover the vestibular bulbs on either side of the vaginal opening. It functions to constrict the vaginal orifice and is involved in clitoral erection and the contraction of the vagina during orgasm.

Innervation

The bulbocavernosus muscle is innervated by the pudendal nerve, which arises from the sacral plexus. The pudendal nerve provides motor innervation to the muscle, allowing it to contract and perform its functions.

Function

The primary functions of the bulbocavernosus muscle include:

• Urination: Assists in expelling the last drops of urine from the urethra in males.
• Ejaculation: Plays a role in the expulsion of semen during ejaculation in males.
• Sexual Function: Contributes to the erection of the penis in males and the clitoris in females, and aids in vaginal contraction during orgasm in females.

Clinical Significance

The bulbocavernosus muscle can be involved in certain medical conditions and procedures:

• Pelvic Floor Dysfunction: Weakness or dysfunction of the bulbocavernosus muscle can contribute to pelvic floor disorders, such as urinary incontinence or sexual dysfunction.
• Bulbocavernosus Reflex: This reflex is used clinically to assess the integrity of the sacral spinal cord segments S2-S4. It involves the contraction of the bulbocavernosus muscle in response to squeezing the glans penis or clitoris.

Also see

• Perineum
• Pudendal nerve
• Pelvic floor
• Erection
• Ejaculation