The pudendal nerve is a major somatic nerve of the sacral plexus, arising from the ventral rami (anterior divisions) of the spinal nerves S2, S3 and S4. After its formation, the pudendal nerve descends and passes between the piriformis and ischiococcygeus muscles. It then leaves the pelvis through the lower part of the greater sciatic foramen, crosses the sacrospinous ligament (close to its insertion to the ischial spine), and then re-enters the pelvis through the lesser sciatic foramen. After re-entering the pelvis, it accompanies the internal pudendal artery and vein, coursing anterosuperiorly through the pudendal canal (also referred to as Alcock’s canal - a structure formed by the fascia of the obturator internus muscle). Inside the pudendal canal, the nerve divides into branches, first giving off the inferior rectal nerve, then the perineal nerve, before continuing as the dorsal nerve of the penis or clitoris.
The pudendal nerve supplies motor control to ho various pelvic muscles, the external urethral sphincter and the external anal sphincter. The perineal nerve innervates muscles of the perineum and pelvic floor, such as the Bulbospongiosus, Ischiocavernosus, and Levator ani muscles (including the iliococcygeus, pubococcygeus and puborectalis). The levator ani muscles can also receive innervation directly from the anterior ramus of the S4 nerve root.
The pudendal nerve also provides the sensation to external genitalia of both sexes and the skin around the anus, anal canal and perineum through its branches. The inferior rectal nerve innervates the perianal skin and lower third of the anal canal, the Perineal nerve innervates the skin of the perineum, labia minora and majora or posterior scrotum, and the dorsal nerve of the penis or clitoris provides innervation to the skin of the penis or clitoris. As such, the pudendal nerve is responsible for the afferent component of penile and clitoral erection.
A pudendal nerve block is a form of analgesia occasionally given before vaginal childbirth, episiotomy and other minor vaginal procedures. To administer a pudendal nerve block, the patient is placed in the lithotomy position, and the ischial spine is palpated transvaginally. Local anaesthetic is then injected into the tissues around the ischial spine. It is essential to aspirate before injecting local anaesthetic to ensure that the local anaesthetic is not administered into the systemic circulation. The procedure is then completed on the other side.
In summary, the pudendal nerve is formed from the sacral plexus and arises from the ventral rami of the spinal nerves S2, S3 and S4. It provides motor control to various pelvic muscles, the external urethral sphincter and the external anal sphincter. It also provides sensation to external genitalia of both sexes and the skin around the anus, anal canal and perineum. The anatomical course of the pudendal nerve varies between individuals; however, its close association to the ischial spine is generally consistent.
The pudendal nerve block is a form of analgesia occasionally given before vaginal childbirth, episiotomy and other minor vaginal procedures. To administer a pudendal nerve block, the patient is placed in the lithotomy position, and the ischial spine is palpated transvaginally. Local anaesthetic is then injected into the tissues around the ischial spine. It is essential to aspirate before injecting local anaesthetic to ensure that the local anaesthetic is not administered into the systemic circulation. The procedure is then completed on the other side.
The pudendal nerve block is an important procedure that helps to manage pain during childbirth and other minor vaginal procedures. As the pudendal nerve is accompanied by the internal pudendal artery, proper aspiration before the injection of local anaesthetic is required to avoid potential complications.
The pudendal nerve is a mixed nerve that is composed of both sensory and motor fibers. It has a variety of functions, and an understanding of the pudendal nerve is important in order to be able to administer a pudendal nerve block, a form of pain relief used in certain clinical situations.
The pudendal nerve originates from the sacral plexus and passes out between the fourth and fifth sacral vertebrae. It then passes through the ischiorectal fossa and downwards into Alcock's canal, where it branches out and innervates the muscles of the perineal region and pelvic floor.
The pudendal nerve also has sensory innervation that provides sensation to the glans and prepuce of the penis and clitoris, as well as the skin of the scrotum and labia. Anterior branches of the pudendal nerve also innervate the levator ani muscles as well as the external urethral sphincter. A branch of the pudendal nerve known as the inferior rectal nerve provides motor supply to the external anal sphincter, and is thus responsible for the voluntary and somatic control of faecal and urinary continence.
The pudendal nerve provides sensory innervation to the external genitalia of both sexes. This is achieved through the following three branches of the pudendal nerve:
The pudendal nerve can also be blocked in order to provide pain relief in certain clinical situations. This procedure is known as a Pudendal Nerve Block. It is occasionally given before vaginal childbirth, episiotomy, and other minor vaginal procedures.
In order to administer a pudendal nerve block, the patient is first placed in the lithotomy position, and the ischial spine is palpated transvaginally. Local anaesthetic is then injected into the area around the ischial spine, and the same procedure is then completed on the opposite side.
It is important to note that the pudendal nerve is accompanied by the internal pudendal artery. As a result, it is essential to aspirate before injecting local anaesthetic during a pudendal nerve block. This ensures that local anaesthetic is not administered into the systemic circulation.
In conclusion, the pudendal nerve has a range of motor and sensory functions, and an understanding of the anatomy of the pudendal nerve is important in order to be able to administer a pudendal nerve block. This procedure provides pain relief in certain clinical situations, and is typically administered prior to vaginal childbirth, episiotomy, and other minor vaginal procedures. However, it is important to note that it is essential to aspirate before injecting local anaesthetic, as the pudendal nerve is accompanied by the internal pudendal artery.
