Origin and Distribution of the Lumbosacral Plexusin Sus scrofa (Mammalia:Suidae)

Abstract

The aim of the present study was describe the origin and distribution of the lumbosacral plexus of Sus scrofa. Thirty specimenswere fixed in 10% formalin solution and prepared according to the macroscopic dissection procedures.TheSus scrofa presented five (40%) or six (60%) lumbar vertebrae and the plexus was derived from L2 to S4 spinal nerves.Eight nerves were originated from the plexus and distributed to the pelvic limb: (1) lateral femoral cutaneous, from L2-L4, branched in the psoas minor, psoas major and internal abdominal oblique muscles; (2) femoral, from L3-L6, supplied the psoas major, psoas minor, iliacus, pectineus and quadriceps femorismuscles; emitted the saphenous nerve that innervates the sartorius muscle; (3) obturator, from L3-L6, distributed to the gracilis, obturator externus, pectineus and adductor muscles; (4) cranial gluteal, from L4-S1,branched the middle gluteal and piriformis muscles; (5) caudal gluteal, from L6-S2, supplied the superficial gluteal muscle; (6) sciatic, from L4-S2, innervated the tensor fasciae latae, middle, accessory and deep gluteal, semitendinosus, semimembranosus, biceps femoris, piriformis, gemelli and quadratus femoris muscles; emitted the (a) tibial nerve, that innervates the caudal muscles of the leg and divided into medial and lateral plantar nerves, terminating as plantar digital nerves; (b) common fibular nerve, divided into superficial and deep fibular nerves, that supplied the cranial and lateral muscles of the leg, terminating as dorsal digital nerves; (7) pudendal, from S2-S4, distributed to perineal muscles; emitted the dorsal nerves of clitoris and penis; (8) caudal rectal, from S2-S4, branched to perineal muscles.