<prompt> Lumbar plexus is situated inAnterior portion of psoasPosterior portion of psoasAnterior portion of quadratus lumborumPosterior portion of quadratus lumborum  <response>: Ans. b Posterior portion of psoas Ref. BDC anatomy Vol. II 3rd ed., 278LUMBAR PLEXUS The lumbar plexus lies in the posterior part of the substance of the PSOAS MAJOR muscle. It is formed by the ventral rami of the upper 4 lumbar nerves.Its branches include:- Ilioinguinal nerve L1- Lateral cutaneous nerve of the thigh L2, L3 dorsal divisions- Lumbosacral trunk L4, 5; ventral trunk- Genitofemoral nerve L1, L2, ventral divisions- Obturator nerve L2, 3, 4; dorsal divisions- Femoral nerve L2, 3, 4; dorsal divisions- Iliohypogastric nerve L1Branches of the lumbar plexusNerveSegmentMuscleMotionSensationIliohypogastricT12 -L1 Inter oblique External oblique Transversus abdominusAnterior abdominal wall Inferior abdominal wall Upper lateral quadrant of buttockIlioinguinalL1Internal obliqueAnterior abdominal wall Internal medial inguinal ligament GenitaliaGenitofemoralL1-L2CremasterTesticular Inferior medial inguinal ligament Spermatic cordLateral femoral cutaneousL2-L3 Anterior, lateral and posterior aspect of thighFemoral Nerve1. Anterior division L2-L4 Sartorius, Pectineus Medial aspect of lower thigh Adduction of thigh Anterior medial skin of thigh2. Posterior division Quadriceps Knee extension Patellar movement Anterior thigh hip and kneeObturator nerve1. Anterior division L2-L4 Gracilis Adductor longus Adductor brevis PectineusThigh adduction Posterior medial thigh Medial knee Hip2. Posterior division Adductor magnus Obturator externusThigh adduction with lateral hip rotationKnee 