The ilioinguinal and iliohypogastric nerves can be severed during a low transverse incision or entrapped during closure, especially if incisions extend beyond the lateral borders of the rectus abdominis muscle (Rahn, 2010). These nerves carry sensory information only, and injury leads to loss of sensation within the areas supplied. Rarely, chronic pain may develop (Whiteside, 2005).
he T 10 dermatome approximates the level of the umbilicus. Analgesia to this level is suitable for labor and vaginal birth. Regional analgesia for cesarean delivery or for puerperal sterilization ideally extends to T4'
Mons Pubis, Labia, and Clitoris
The pudenda-commonly designated the vulva-includes all structures visible externally from the symphysis pubis to the perineal body. This includes the mons pubis, labia majora and minora, clitoris, hymen, vestibule, urethral opening, greater vestibular or Bartholin glands, minor vestibular glands, and paraurethral glands (Fig. 2-3). he vulva receives innervations and vascular support from the pudendal nerve (p. 22).
he mons pubis is a fat-illed cushion overlying the symphysis pubis. After puberty, the mons pubis skin is covered by curly hair that forms the triangular escutcheon, whose base aligns with the upper margin of the symphysis pubis. In men and some hirsute women, the escutcheon extends farther onto the anterior abdominal wall toward the umbilicus.
Labia majora usually are 7 to 8 cm long, 2 to 3 cm wide, and 1 to 1.5 cm thick. They are continuous directly with the mons pubis superiorly, and the round ligaments terminate at their upper borders. Hair covers the labia majora, and apocrine, eccrine, and sebaceous glands are abundant. Beneath the skin, a dense connective tissue layer is nearly void of muscular elements but is rich in elastic fibers and fat. his fat mass provides bulk to the labia majora and is supplied with a rich venous plexus. During pregnancy, this vasculature may develop varicosities, especially in multiparas, from increased venous pressure created by the enlarging uterus. hey appear as engorged tortuous veins or as small grapelike clusters, but they are typically asymptomatic and require no treatment.
Each labium minus is a thin tissue fold that lies medial to each labium majus. he labia minora extend superiorly, where each divides into two lamellae. From each side, the lower lamellae fuse to form the frenulum of the clitoris, and the upper lamellae merge to form the prepuce (see Fig. 2-3). Inferiorly, the labia minora extend to approach the midline as low ridges of tissue that join to form the fourchette. The labia minora dimensions vary greatly among individuals, with lengths from 2 to 10 cm and widths from 1 to 5 cm (Lloyd, 2005).
Structurally, the labia minora are composed of connective tissue with numerous vessels, elastin ibers, and very few smooth muscle ibers. hey are supplied with many nerve endings and are extremely sensitive (Ginger, 20i1i1a; Schober, 2015). The epithelia of the labia minora difer with location. Thinly keratinized stratiied squamous epithelium covers the
Glans of clitoris
Inferior fascia of levator ani mm./
External anal sphincter m.