The perineal nerve is a nerve of the pelvis. It arises from the

pudendal nerve The pudendal nerve is the main nerve of the perineum. 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 fem ...

in the

pudendal canal The pudendal canal (also called Alcock's canal) is an anatomical structure in the pelvis through which the internal pudendal artery, internal pudendal veins, and the pudendal nerve pass. Structure The pudendal canal is formed by the fascia of the ...

. It gives superficial branches to the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...

, and a deep branch to

muscles Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of musc ...

. It supplies the skin and muscles of the

perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...

. Its latency is tested with

electrodes An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials dep ...

Structure

The perineal nerve is a branch of the

. It lies below the

internal pudendal artery 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. Structure The internal pudendal artery is the terminal branch of the anterior trunk of ...

. It accompanies the

perineal artery The perineal artery (superficial perineal artery) arises from the internal pudendal artery, and turns upward, crossing either over or under the superficial transverse perineal muscle, and runs forward, parallel to the pubic arch, in the interspa ...

. It passes through the pudendal canal for around 2 or 3 cm. Whilst still in the canal, it divides into superficial branches and a deep branch. The superficial branches of the perineal nerve become the

posterior scrotal nerves The posterior scrotal branches (in men) or posterior labial branches (in women) 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 r ...

in men,Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 263 and the

posterior labial nerves The posterior labial nerves are branches of the pudendal nerve. The counterparts in males are the posterior scrotal nerves. See also * Anterior labial nerves The anterior labial nerves are branches of the ilioinguinal nerve. The nerves innervat ...

in women. The

deep branch of the perineal nerve The deep branch of the perineal nerve (or muscular branches) 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, ischiocavern ...

(also known as the "muscular" branch) travels to the muscles of the perineum. Both of these are superficial to the

dorsal nerve of the penis The dorsal nerve of the penis is the deepest division of the pudendal nerve; it accompanies the internal pudendal artery along the ramus of the ischium; it then runs forward along the margin of the inferior ramus of the pubis, between the superio ...

or the

dorsal nerve of the clitoris 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. It travels from below the infe ...

Function

The perineal nerve supplies the skin and muscles of the

. The superficial branches supply sensation to the perineum, and the

scrotum The scrotum or scrotal sac is an anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scrotum co ...

in men or the

labia majora The labia majora (singular: ''labium majus'') are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva. The labia majo ...

in women. The deep branch supplies

superficial transverse perineal muscle The transverse perineal muscles (transversus perinei) are the superficial and the deep transverse perineal muscles. Superficial transverse perineal ...

, the

bulbospongiosus muscle The bulbospongiosus muscle (bulbocavernosus in older texts) is one of the superficial muscles of the perineum. It has a slightly different origin, insertion and function in males and females. In males, it covers the bulb of the penis. In fema ...

, the

ischiocavernosus muscle The ischiocavernosus muscle (erectores penis ''or'' erector clitoridis in older texts) is a muscle just below the surface of the perineum, present in both men and women. Structure It arises by tendinous and fleshy fibers from the inner surface o ...

, the

bulb of penis Just before each crus of the penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both ver ...

levator ani 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. It is attached to the inner surface of each side of the ...

, and the

external anal sphincter The external anal sphincter (or sphincter ani externus ) is a flat plane of skeletal muscle fibers, elliptical in shape and intimately adherent to the skin surrounding the margin of the anus. Anatomy The external anal sphincter measures about 8 ...

Clinical significance

The latency of the perineal nerve can be measured with

. It is used to test nerve function.

Additional images

File:Gray837.png, Sacral plexus of the right side. (Perineal nerve visible at center right.)

References

External links

* - "The Female Perineum: The Perineal Nerve" * * * {{Authority control Nerves of the lower limb and lower torso