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. It gives superficial branches to the
skin, 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
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 ...
.
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 in women.
The
deep branch of the perineal nerve (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.
Function
The perineal nerve 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 ...
.
The superficial branches supply sensation to the perineum, and the
scrotum in men or the
labia majora 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
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.
Clinical significance
The latency of the perineal nerve can be measured 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 ...
.
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"
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{{Authority control
Nerves of the lower limb and lower torso