The pudendal nerve is the main nerve of the perineum. It is a mixed nerve and also conveys sympathetic autonomic fibers. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter.
The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis.
The ischiocavernosus muscle is a muscle just below the surface of the perineum, present in both men and women.
The bulbospongiosus muscles are a subgroup of the superficial muscles of the perineum. They have a slightly different origin, insertion and function in males and females. In males, these muscles cover the bulb of the penis, while in females, they cover the vestibular bulbs.
The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia.
The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends.
The inferior rectal artery is an artery that supplies blood to the lower third of the anal canal below the pectinate line.
The perineal nerve is a nerve of the pelvis. It arises from the pudendal nerve in the pudendal canal. It gives superficial branches to the skin, and a deep branch to muscles. It supplies the skin and muscles of the perineum. Its latency is tested with electrodes.
The ischioanal fossa is the fat-filled wedge-shaped space located lateral to the anal canal and inferior to the pelvic diaphragm. It is somewhat prismatic in shape, with its base directed to the surface of the perineum and its apex at the line of meeting of the obturator and anal fasciae.
The pudendal canal is an anatomical structure formed by the obturator fascia lining the lateral wall of the ischioanal fossa. The internal pudendal artery and veins, and pudendal nerve pass through the pudendal canal, and the perineal nerve arises within it.
The posterior scrotal branches are two in number, medial and lateral. They are branches of the perineal nerve, which is itself a branch of the pudendal nerve. The pudendal nerve arises from spinal roots S2 through S4, travels through the pudendal canal on the fascia of the obturator internus muscle, and gives off the perineal nerve in the perineum. The major branch of the perineal nerve is the posterior scrotal/posterior labial.
The inferior rectal nerves usually branch from the pudendal nerve but occasionally arises directly from the sacral plexus; they cross the ischiorectal fossa along with the inferior rectal artery and veins, toward the anal canal and the lower end of the rectum, and is distributed to the sphincter ani externus and to the integument (skin) around the anus.
The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term "inferior fascia of urogenital diaphragm", used in older texts, is considered equivalent to the perineal membrane.
The superficial perineal pouch is a compartment of the perineum.
The deep perineal pouch is the anatomic space enclosed in part by the perineum and located superior to the perineal membrane.
The urogenital triangle is the anterior part of the perineum. In female mammals, it contains the vulva, while in male mammals, it contains the penis and scrotum.
The anal triangle is the posterior part of the perineum. It contains the anus in mammals.
The dorsal nerve of the clitoris is a nerve in females that branches off the pudendal nerve to innervate the clitoris. The nerve is important for female sexual pleasure, and it may play a role in clitoral erections.
The anterior labial nerves are branches of the ilioinguinal nerve. The nerves labia majora. The equivalent nerves in the male are the anterior scrotal nerves.
The deep branch of the perineal nerve is a nerve of the perineum. It is a branch of the perineal nerve, from the pudendal nerve. It supplies the superficial transverse perineal muscle, bulbospongiosus muscle, ischiocavernosus muscle, the bulb of penis, levator ani, and the external anal sphincter.
