Innervation of Female Reproductive Organs

An inferior group of a few small nerves arises from the inferior hypogastric plexus and from the nerve loops around the lower end of the ureter (see page 195). This third group is closely associated with small nerves given off from the anterior part of the inferior hypogastric plexus to the seminal vesicles, prostate gland, ejaculatory ducts, and the base of the urinary bladder. The prostatic and urethral nerve fibers communicate with branchlets of the pudendal nerves, and offshoots from these united nervelets innervate the corpora cavernosa, the corpus spongiosum and the part of the urethra within it, and the bulbourethral glands. The nerve fibers supplying the cavernous structures and their vessels are termed the penile cavernous nerves, whereas their ramifications are often called the cavernous plexuses.

FEMALE REPRODUCTIVE ORGANS

The autonomic nerves supplying the female genital organs have similar origins to those supplying the male genital organs.

The superior group coalesces to form two or three slender nerves, which accompany the ovarian artery and supply nerve fibers to it and to the ovary and outer parts of the uterine tube. Their terminal fibers communicate with uterine fibers innervating the inner end of the uterine tube. Most of the afferent fibers in these nerves enter the spinal cord through the posterior roots of the tenth and the eleventh thoracic nerve, although a number may enter through the ninth or twelfth nerves.

The middle group helps to supply the ovaries and the uterine tube and vessels and gives off fascicles to the common and external iliac arteries.

The inferior group consists of nerves that enter the cervix of the uterus and the vagina directly, often alongside branches of the uterine and vaginal vessels, and other nerves that ascend with or near the uterine artery, supplying nerve fibers to the body and fundus of the uterus, as well as to the artery and its branches. The terminal nerve fibers supply the uterine end and isthmus of the uterine tube, where they communicate with corresponding nerve fibers from the superior and middle groups of nerves.

The uterine nerves ramify throughout the myometrium. The fibers, which are predominantly unmyelinated and adrenergic in type, are most plentiful around the uterine end of the uterine tube, in the cervix, and near the arterial branches.

The nerves entering the upper part of the vagina contain tiny ganglia. They break up into nerve fibers that supply the vaginal arteries and give off fascicles to the muscular and mucous coats of the vagina and urethra, the erectile tissue of the vestibular bulb and corpora cavernosa clitoridis, and the greater and lesser vestibular glands. These nerves contain a mixture of sympathetic and parasympathetic efferent and afferent fibers.

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