Anatomy Lumbar And Sacral Plexus

Front 1

Iliohypogastric Nerve

Back 1

Source: lumbar plexus (ventral primary ramus of spinal nerve L1)

Branch: lateral and anterior cutaneous brs.

Motor(Efferent): muscles of the lower abdominal wall

Sensory(Afferent): skin of the lower abdominal wall, upper hip and upper thigh

Front 2

Ilioinguinal Nerve

Back 2

Source: lumbar plexus (ventral primary ramus of spinal nerve L1)

Branch: anterior cutaneous br. (also known as: anterior labial/scrotal n.)

Motor(Efferent): muscles of the lower abdominal wall

Sensory(Afferent): skin of the lower abdominal wall and anterior scrotum/labium majus

Front 3

Genitofemoral Nerve

Back 3

Source: lumbar plexus (ventral primary rami of spinal nerves L1-L2)

Branch: genital br., femoral br.

Motor(Efferent): cremaster m.

Sensory(Afferent): skin of the anterior scrotum/labia majora & upper medial thigh

Front 4

Lateral Femoral Cutaneous Nerve

Back 4

Source: lumbar plexus (ventral primary rami of spinal nerves L2-L3)

Branch: anterior & posterior brs.

Motor(Efferent): sympathetic motor innervation to skin

Sensory(Afferent): skin of the lateral thigh

Front 5

Femoral Nerve

Back 5

Source: lumbar plexus (ventral primary rami of spinal nerves L2-L4)

Branch: anterior femoral cutaneous brs., nn. to: sartorius m., rectus femoris m., vastus lateralis m., vastus intermedius m., vastus medialis m., pectineus m.

Motor(Efferent): sartorius, rectus femoris, vastus lateralis, vastus intermedius, vastus medialis, pectineus

Sensory(Afferent): skin of anterior thigh

Front 6

Obturator Nerve

Back 6

Source: lumbar plexus (ventral primary rami of spinal nerves L2-L4)

Branch: anterior and posterior brs.

Motor(Efferent): muscles of the medial thigh: adductor longus m., adductor brevis m. and adductor magnus m., gracilis m., obturator externus m.

Sensory(Afferent): skin of the lower medial thigh

Front 7

Lumbosacral Trunk

Back 7

Source: part of the ventral primary ramus of L4 united with the ventral primary ramus of L5

Branch: no named branches; it contributes to the formation of the sacral plexus

Motor(Efferent): muscles of the hip and posterior thigh

Sensory(Afferent): skin of the perineum, posterior thigh, leg and foot (excluding the medial side of the leg and foot)

Front 8

Superior Gluteal Nerve

Back 8

Source: sacral plexus (ventral primary rami of spinal nerves L4-L5, S1)

Branch: superior & inferior brs.

Motor(Efferent): gluteus medius m., gluteus minimus m., tensor fasciae latae m.

Sensory(Afferent): none

Front 9

Inferior Gluteal Nerve

Back 9

Source: sacral plexus (ventral primary rami of spinal nerves L5, S1-S2)

Branch: no named branches

Motor(Efferent): gluteus maximus m.

Sensory(Afferent): none

Front 10

Nerve to Piriformis

Back 10

Source: sacral plexus S1 S2

Branch:

Motor(Efferent):

Sensory(Afferent):

Front 11

Sciatic Nerve

Back 11

Source: sacral plexus (ventral primary rami of spinal nerves L4-L5 and S1-S3)

Branch: tibial n., common fibular (peroneal) n.

Motor(Efferent): semitendinosus m., semimembranosus m., biceps femoris m., ischioconylar part of the adductor magnus m.; its branches supply all muscles of the leg and foot

Sensory(Afferent): its branches supply the skin of the leg and foot (excluding the medial side of leg & foot)

Front 12

Tibial Nerve

Back 12

Source: sciatic n. anterior spinal nerves L4-L5 and S1-S3

Branch: medial sural cutaneous n., medial calcaneal brs., medial and lateral plantar nn.

Motor(Efferent): lots

Sensory(Afferent): skin of the plantar surface of the foot and toes; skin of the dorsal surface of the distal toes

Front 13

Common Fibular Nerve

Back 13

Source: sacral plexus (posterior rami of spinal nerves L4-L5 and S1-S2)

Branch: lateral sural cutaneous n., superficial and deep fibular nn.

Motor(Efferent): superficial fibular n., fibularis longus and brevis mm., deep fibular n., tibialis anterior m., extensor hallucis longus m., extensor digitorum longus m., fibularis tertius m., extensor digitorum brevis m.and extensor hallucis brevis m.

Sensory(Afferent): superficial fibular n.: distal 1/3 of the anterior surface of the leg, etc.

Front 14

Nerve to Quadratus Femoris

and Inferior Gemellus

Back 14

Source: sacral plexus (ventral primary rami of spinal nerves L4-L5, S1)

Branch: n. to the inferior gemellus m.

Motor(Efferent): quadratus femoris m., inferior gemellus m.

Sensory(Afferent): none

Front 15

Nerve to Obruator Internus

and Superior Gemellus

Back 15

Source: sacral plexus (ventral primary rami of spinal nerves L5-S2 )

Branch: n. to the superior gemellus m.

Motor(Efferent): obturator internus m., superior gemellus m.

Sensory(Afferent): none

Front 16

Posterior cutaneous Nerve of Thigh

aka posterior femoral cutaneous n.

Back 16

Source: sacral plexus (ventral primary rami of spinal nerves S1-S3)

Branch: inferior cluneal nn.; perineal br.

Motor(Efferent): sympathetic motor innervation to skin

Sensory(Afferent): skin of the lower buttock & posterior thigh

Front 17

Perforating Cutaneous Nerve

Back 17

Source: sacral plexus (ventral primary rami of spinal nerves S2-3)

Branch: no named branches

Motor(Efferent): none

Sensory(Afferent): skin of the inferomedial buttock

Front 18

Pudendal Nerve

Back 18

Source: ventral primary rami of spinal nerves S2-S4 (sacral plexus)

Branch: inferior rectal n., perineal n., dorsal n. of the clitoris/penis

Motor(Efferent): its branches supply: external anal sphincter, bulbospongiosus m., ischiocavernosus m., superficial & deep transverse perineus mm., sphincter urethrae m., sphincter urethrovaginalis, compressor urethrae

Sensory(Afferent): its branches supply: skin of the anus, posterior scrotum/labium majus, clitoris/penis

Front 19

Anococcygeal Nerve

Back 19

Source: coccygeal plexus (S4-C1)

Branch: no named branches

Motor(Efferent): none

Sensory(Afferent): skin overlying the coccyx