Lumbosacral Plexus Organization Flashcards Preview

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Flashcards in Lumbosacral Plexus Organization Deck (20)
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1

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

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

State segmental origin and to what is communicates to:

Lumbosacral trunk

Semental Origin:L4,5

Communicates to sacral plexus

10

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

11

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)

12

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

13

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

14

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

15

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

16

State course, division, segmental origin, fiber type and distribution:

Nerve to qudratus femoris

  • Course: exits through the greater sciatic foramen below piriformis, in the space medial to the sciatic nerve and superior to the superior gemellus. Runs vertically and deep to the obturator internus, gemelli and quadratus femoris
    • Most lateral
  • Division: anterior division of sacral plexus
  • Segmental origin: L5,S1
  • Fiber type: motor
  • Distribution: quadratus femoris and inferior gemellus

17

State course, division, segmental origin, fiber type and distribution:

Sciatic nerve

  • Course: exits the greater sciatic foramen, inferior to piriformis (may go pierce muscle belly).
  • Division: anterior and posterior divisions of sacral plexus
    • Common fibular nerve is part of posterior division of sacral plexus
    • Tibial nerve is part of anterior division of sacral plexus
  • Segmental origin: L4,5,S1,2,3
  • Fiber type: motor and sensory
  • Distribution:
    • Motor: muscles innervated by tibial, common fibular, superficial fibular, deep fibular, medial plantar and lateral plantar (all arise from either tibial or common fibular branch of sciatic)
    • Sensory: via medial sural cutaneous (from tibial), lateral sural cutaneous (from commmon fibular), fibular communicating branch (from common fibular) and sural nerve (from the joining of medial and lateral sural via fibular communicating branch); supplying skin of posterior and lateral aspect of leg and lateral side of foot

18

State course, division, segmental origin, fiber type and distribution:

Tibial nerve

  • Course: one of the terminal branches of the sciatic nerve, arises from the sciatic nerve and descends vertically through the center of the popliteal fossa.
  • Division: anterior division of sacral plexus
  • Segmental origin: L4,5,S1,2,3
  • Fiber type: motor and sensory
  • Distribution:
    • Motor: biceps femoris, semitendinosus, semimembranosus, gastrocnemius (both heads), plantaris, soleus, FHL, FDL, tibialis posterior, popliteus, foot intrinsic muscles (via medial and lateral plantar nerves)
    • Sensory: via medial sural cutananeous nerve, supplying skin of lateral part of the posterior aspect of leg and lateral side of foot

19

State course, division, segmental origin, fiber type and distribution:

Common fibular nerve

  • Course: one of the terminal branches of the sciatic nerve, runs lateral to the tibial nerve and descends near the medial border of the biceps femoris muscle and exits the popliteal fossa superficial to the lateral head of the gastrocnemius.
  • Division: posterior division of sacral plexus
  • Segmental origin: L4,5,S1,2
  • Fiber type: motor and sensory
  • Distribution:
    • Motor: biceps femoris short head,
      • Deep fibular: EHL, EDB, tibialis anterior, EDL, fibularis tertius, EHB
      • Superficial fibular: fibularis longus and brevis
    • Sensory: via lateral sural cutaneous, supplying skin of lateral part of the posterior aspect of leg and lateral side of foot

20

State course, division, segmental origin, fiber type and distribution:

Pudental nerve

  • Course: passes deep to the sacrotuberous ligament through the lesser sciatic foramen into the perineum, medial to internal pudendal artery.
  • Division: anterior divisions of sacral plexus
  • Segmental origin: S2,3,4
  • Fiber type: motor and sensory
    • Motor: puborectalis, pubococcygeus and iliococcygeus
    • Sensory:
  • Distribution: structures in perineum: sensory to genitalia; muscular branches to perineal muscles, external urethral sphincter, and external anal sphincter