The bulbospongiosus is a muscle located in the perineum, which is a surface that is found next to the coccyx in humans. Although the muscle is present in both genders, the exact location differs. The male bulbospongiosus is located on the penis bulb while in females it is found over the vestibular bulb, which is also known as the clitoral bulb. Functionally, the muscle also differs between genders with the male version being involved in erection of the penis and ejaculation while the female muscle is used for clitoral erection.
The exact location of the muscle is just in front of the anus and along the middle of the perineum. There are actually two parts to the muscle that are symmetrical. The origin of the bulbospongiosus is from the tendon part of the perineum and from there it runs to either the bulb of the penis or the vestibular bulb. In anatomy the muscle is said to be superficial — in other words it is on the surface.
The bulbospongiosus is innervated by the same nerve, the perineal, in both male and female bodies. It is a branch of the pudendal nerve. In shape the bulbospongiosus is different from many muscles in that the fibers don’t run parallel to each other but instead diverge outwards. The fibers in the middle of the muscle are the ones, which wrap around the bulb.
In males, the main functions of the bulbospongiosus is to increase the feeling of orgasm and assist with erection and ejaculation. An erection is achieved using the anterior part of the muscle, which is the section that is toward the front of the body. This part of the muscle contracts during erection, which puts pressure on a vein that runs into the penis.
In women the bulbospongiosus contributes to the feeling of orgasm and is involved in clitoral erection. The muscle is also involved in closing the vagina. Aside from the functions that are unique to male and females there are also some actions that are common to both.
The muscle is involved in emptying the urethra’s canal after the person has emptied his or her bladder. During urination the muscle is relaxed for most of the process and only becomes active towards the end. The middle part of the muscle can also help the urethra to become erect through compression of certain tissues in the bulb of the penis.