Lumbar Plexus

Question 1

General knowledge

Answer 1

Formed from T12, L1-4
Nerves from plexus supply lower abdomen and ant/med portions of lower extremities
Saphenous - largest and longest femoral cutaneous branch

Question 2

Iliohypogastric

Answer 2

Central rami: T12, L1

Distribution: skin and muscles of lower back, hip, and lower abdomen

Question 3

Ilioinguinal

Answer 3

Ventral rami: L1
Distribution:
Skin - of upper medial thigh, external genitalia
Muscles - lower abdominal wall

Question 4

Genitofemoral

Answer 4

Ventral rami: L1-2

Distribution: skin of upper ant thigh (upper femoral triangle) and external genitalia

Question 5

Lateral femoral cutaneous

Answer 5

Ventral rami: L2-3
Distribution:
Skin - of the lateral thigh

Question 6

Femoral

Answer 6

Ventral rami: L2-4
Distribution:
Skin - ant/med surface of the thigh, through the ant femoral cutaneous
Muscles - sartorius, iliopsoas, quadriceps demotic, pectineus

Question 7

Saphenous

Answer 7

Ventral rami: L2-4
Distribution: skin of med lower leg
Pathway: Passes deep to sartorius w/femoral artery in adductor canal
Pierces fascia latae b/w gracilis and sartorius tendons to become subcutaneous, then accompanies great saphenous vein
Leaves adductor canal above the knee via infrapatellar branch and continues down med lower leg

Question 8

Obturator

Answer 8

Ventral rami: L2-4
Distribution:
Skin - circular area of medial thigh above knee
Muscles - adductor longus/magnus/brevis, gracious, pectineus, obturator externus