Lumbosacral Plexus Organization Flashcards
State course, division, segmental origin, fiber type and distribution:
Subcostal nerve
- Course: pass posterior to the lateral arcuate ligaments into the abdomen, and run inferolaterally on the anterior surface of the quadratus lumborum (Fig. 2.97). They pass through the transversus abdominis and internal oblique muscles to supply the external oblique and skin of the anterolateral abdominal wall.
- Division: no division
- Segmental origin: T12
- Fiber type: sensory
- Distribution: overlying skin, superior to iliac crest and inferior to umbilicus
State course, division, segmental origin, fiber type and distribution:
Lateral cutaneous branch of Iiliohypogastric nerve
- Course: runs downward over the posterolateral aspect of the iliac crest.
- Division: no division
- Segmental origin: L1
- Fiber type: sensory
- Distribution: superolateral quadrant of buttocks
State course, division, segmental origin, fiber type and distribution:
Ilioinguinal nerve
Course: passes through inguinal canal
Division: no division
Segmental origin: anterior rami of L1
Fiber type: sensory
Distribution: skin over medial femoral triangle
State course, division, segmental origin, fiber type and distribution:
Lateral femoral cutaneous nerve
- Course: passes deep and lateral to the inguinal ligament, located on the anterolateral aspect of thigh.
- Division: posterior division of lumbar plexus
- Segmental origin: L2,3
- Fiber type: sensory
- Distribution: anterior and lateral aspect of thigh
State course, division, segmental origin, fiber type and distribution:
Genitofemoral nerve
- Course: Descends anterior surface of psoas
major, near saphenous hiatus just below inguinal ligament. - Division: no division
- Segmental origin: anterior rami of L1,2
- Fiber type: sensory and motor
- Distribution
- Sensory: scrotum/labia and lateral part of femoral triangle
- Motor: cremaster muscle
State course, division, segmental origin, fiber type and distribution:
Femoral nerve
- Course: most lateral structure of the femoral triangle (runs lateral to the femoral artery) and deep to the sartorius muscle.
- Division: posterior division of lumbar plexus
- Segmental origin: L2,3,4
- Fiber type: motor and sensory
- Distribution:
- Motor: sartorius, vastus lateralis, vastus medialis, vastus intermedius, rectus femoris, pectineus
- Sensory: via its anterior cutaneous branches of femoral nerve
State course, division, segmental origin, fiber type and distribution:
Obturator nerve
- Course:
- Anterior branch: superficial to obturator externus and adductor brevis and deep the pectineus.
- Posterior branch: pierces through the belly of obturator externus and runs posterior to adductor brevis and anterior to adductor magnus
- Division: anterior division of lumbar plexus
- Segmental origin: L2,3,4
- Fiber type: motor and sensory
- Distribution:
- Motor: adductor brevis, adductor longus, adductor magnus and gracilis
- Sensory: via cutaneous branches of obturator nerve skin on middle part of medial thigh
State course, division, segmental origin, fiber type and distribution:
Accessory obturator nerve
- Course:
- Division: anterior division of lumbar plexus
- Segmental origin: L3,4
- Fiber type: motor and sensory
- Distribution:
- Motor: pectineus
- Sensory: via cutaneous branches of obturator nerve skin on middle part of medial thigh
State segmental origin and to what is communicates to:
Lumbosacral trunk
Semental Origin:L4,5
Communicates to sacral plexus
State course, division, segmental origin, fiber type and distribution:
Anterior cutaneous branch of femoral
- Course: the more anterior branch runs down the midline of the thigh and terminates close to the patella and the more medial branch runs closely (just laterally) to the greater saphenous vein.
- Division: posterior division of lumbar plexus
- Segmental origin: L2,3,4
- Fiber type: sensory
- Distribution: anterior and medial aspect of thigh
State course, division, segmental origin, fiber type and distribution:
Posterior cutaneous branch of femoral nerve
- Course: runs through the greater sciatic foramen deep to the piriformis near the sciatic nerve and the gluteus maximus. Can be located below the inferior border of gluteus maximus and between the ischial tuberosity and greater trochanter and between biceps femoris and semitendinosus muscles
- Division: none
- Segmental origin: S1,2,3
- Fiber type: sensory
- Distribution: Supplies skin of inferior half of buttocks (through inferior clunial nerves), skin over posterior thigh and popliteal fossa, and skin of lateral perineum and upper medial thigh (via its perineal branch)
State course, division, segmental origin, fiber type and distribution:
Saphenous Nerve
- Course: traverses adductor canal, pierces deep fascia of medial aspect of the knee and descends with the greater saphenous vein down the medial aspect of the leg.
- Terminal branch of femoral nerve.
- Division: posterior division of lumbar plexus
- Segmental origin: L2,3,4
- Fiber type: sensory
- Distribution: skin on medial side of leg and foot
State course, division, segmental origin, fiber type and distribution:
Superior gluteal nerve
- Course: runs through the greater sciatic notch and superior to the piriformis
- Located deep to the gluteus medius and superficial to gluteus minimus
- Usually accompanied by superior gluteal arteries
- Division: posterior division of sacral plexus
- Segmental origin: L4,5,S1
- Fiber type: motor
- Distribution: gluteus medius, gluteus minimus, tensor fascia lata
State course, division, segmental origin, fiber type and distribution:
Inferior gluteal nerve
- Course: runs through the greater sciatic foramen, inferior to the piriformis.
- Usually accompanied by inferior gluteal artery and vein
- Division: posterior division of sacral plexus
- Segmental origin: L5,S1,2
- Fiber type: motor
- Distribution: gluteus maximus
State course, division, segmental origin, fiber type and distribution:
Nerve to obturator internus
- Course: exits through the greater sciatic foramen below piriformis, in the space medial to the sciatic nerve and superior to the superior gemellus.
- located lateral to the internal pudendal artery
- Division: anterior division of sacral plexus
- Segmental origin: L5,S1
- Fiber type: motor
- Distribution: obturator internus and superior gemellus