Final answer:
The pudendal nerve is essential for urinary continence, voluntary micturition, and sexual functions by controlling the external urethral sphincter and muscles of the perineum. It originates from the S2-S4 nerves of the sacral plexus and innervates structures like the bulbourethral glands and the corpus spongiosum in males.
Step-by-step explanation:
The pudendal nerve is a crucial nerve arising from the S2-S4 nerves of the sacral plexus, playing a vital role in the urogenital and anorectal regions of the body. It allows for the voluntary control of the external urethral sphincter and the muscles around the anus. Specifically, it facilitates the functions of voluntary micturition and maintaining continence by contracting during the filling of the bladder. Sympathetic activity via the hypogastric nerves reduces contraction of the detrusor muscle while, as the bladder fills, afferent signals activate parasympathetic neurons leading to detrusor contraction and bladder emptying through the help of released acetylcholine.
The deep muscles of the perineum and the bulbourethral glands (Cowper's glands) are also innervated by branches of the pudendal nerve. The bulbourethral glands are responsible for secreting mucus during sexual stimulation, which neutralizes the acidic environment of the urethra and aids in lubrication. In males, the pudendal nerve contributes to the process of erection and ejaculation by innervating the areas that include the corpus spongiosum and the external urethral sphincter. The healthy function of this nerve is essential for both urinary and sexual health.