Anatomy, Abdomen and Pelvis, Pudendal Nerve
Kevin J. Kinter, Bruce W. Newton
Abstract
The pudendal nerve carries motor and sensory axons arising from the ventral rami of the sacral spinal nerves S2-S4. The nerve is paired, meaning that it is found bilaterally, one on the left and one on the right side of the body. The left and right pudendal nerves give off branches, innervating regions of the rectal canal, anus, perineum, and external genitalia. Interestingly, due to the regions it innervates, the nerve’s name is originally derived from the Latin word “pudendum”, meaning “thing to be ashamed of”. The nerve is important for carrying sensations from the clitoris and penis, labia minora, vaginal vestibule and the lower one-fifth of the vaginal canal, and the posterior aspects of the labia majora and scrotum. It is involved in controlling somatic muscles involved in penile and clitoral erection and in ejaculation in males. Additionally, this nerve innervates the external anal and external urethral sphincters. Based on its location, the nerve can be susceptible to injury, most notably during childbirth. Pudendal nerve injuries can result in loss of sensation in the nerve's distribution, fecal and urinary incontinence, and sexual dysfunction.