These plexi help enhance and coordinate many functions such as muscle contraction, maintenance of body coordination and control, reaction to sensation etc. The sacral plexus comprises of spinal levels from L4-S4 and innervates the pelvis, genitals, thighs, buttocks, calves and feet. The sacral plexus lies in the back of the pelvis, between the piriformis muscle and the pelvis fascia and nerves coming from this plexus converge toward the lower part of the greater sciatic foramen and unite to form a flattened band, which continues primarily as the sciatic nerve. All nerves that root from the plexus either have anterior or posterior divisions and the posterior division has less nerves than the anterior. The posterior division contains the superior gluteal nerve (L4-S1), inferior gluteal nerve (L5-S2) and the nerve to piriformis (S1, S2). The anterior division contains the nerve to quadratus femoris (L4-S1), the nerve to obturator internus ( L5-S2), the posterior femoral cutaneous nerve ( S1-S3), Pudendal (S2-S4) and Coccygeal (S5-Co1). The sciatic nerve, which is the largest nerve in the body, is a combination of two nerves: the tibial nerve and the common fibular nerve. The tibial nerve (L4-S3), comes from the anterior division and branches off into the medial and lateral plantar nerves and the common fibular nerve (L4-S2), comes from the posterior division of the plexus and branches off into the superficial and deep nerves. These come together to make the sacral…
