Lumbar Plexus Flashcards
Where is the lumbar plexus located?
Posterior abdominal wall
What forms the lumbar plexus?
Ventral rami of L1 - L4
Name the 4 nerves found laterally to psoas in descending order
- Iliohypogastric
- Ilioinguinal
- Lateral cutaneous of the thigh
- Femoral
Name the nerve found anterior to the psoas
Genitofemoral
Name the nerve and trunk found medial to the psoas
Obturator nerve and lumbosacral trunk
Where does the iliohypogastric nerve originate?
L1
What is the sensory function of the iliohypogastric nerve?
Innervate skin of abdominal wall just above inguinal ligament
What is the motor function of the iliohypogastric nerve?
Give branches to anterior abdominal wall muscles except rectus abdominis
Where does the ilioinguinal nerve originate?
L1
What is the sensory function of the ilioinguinal nerve?
Innervate skin of the groin and scrotum or labium majora
What is the motor function of the ilioinguinal nerve?
Give branches to anterior abdominal wall muscles except rectus abdominis
What is the sensory function of the lateral cutaneous nerve of the thigh?
Innervate skin over the lateral surface of the thigh
Describe the route of the lateral cutaneous nerve of the thigh to enter the thigh
Crosses iliac fossa in front of iliacus and enters the thigh behind the inguinal ligament
Where does the femoral nerve originate?
L2 - L4
What is the sensory and motor function of the femoral nerve?
Innervate muscle and skin at the front of the thigh
Where does the obturator nerve originate?
L2 - L4
How does the obturator nerve leave the pelvis?
Passes through obturator foramen into thigh
What is the sensory function of the obturator nerve?
Innervate skin on the medial surface of the thigh
What is the motor function of the obturator nerve?
Give branches to adductor group of muscles in thigh
Where does the genitofemoral nerve originate?
L1 - L2
What are the 2 branches of the genitofemoral nerve?
- Genital
2. Femoral
Where does the genital branch of the genitofemoral nerve supply?
Motor function to cremaster muscle
Where does the genital nerve pass after the genitofemoral nerve divides?
Spermatic cord in males / Inguinal canal in females
Where does the femoral branch of the genitofemoral nerve supply?
Sensory function to a small area of skin of the thigh
