Lumbar Plexus

Question 1

Where is the lumbar plexus located?

Answer 1

Posterior abdominal wall

Question 2

What forms the lumbar plexus?

Answer 2

Ventral rami of L1 - L4

Question 3

Name the 4 nerves found laterally to psoas in descending order

Answer 3

1. Iliohypogastric
2. Ilioinguinal
3. Lateral cutaneous of the thigh
4. Femoral

Question 4

Name the nerve found anterior to the psoas

Answer 4

Genitofemoral

Question 5

Name the nerve and trunk found medial to the psoas

Answer 5

Obturator nerve and lumbosacral trunk

Question 6

Where does the iliohypogastric nerve originate?

Answer 6

L1

Question 7

What is the sensory function of the iliohypogastric nerve?

Answer 7

Innervate skin of abdominal wall just above inguinal ligament

Question 8

What is the motor function of the iliohypogastric nerve?

Answer 8

Give branches to anterior abdominal wall muscles except rectus abdominis

Question 9

Where does the ilioinguinal nerve originate?

Answer 9

L1

Question 10

What is the sensory function of the ilioinguinal nerve?

Answer 10

Innervate skin of the groin and scrotum or labium majora

Question 11

What is the motor function of the ilioinguinal nerve?

Answer 11

Give branches to anterior abdominal wall muscles except rectus abdominis

Question 12

What is the sensory function of the lateral cutaneous nerve of the thigh?

Answer 12

Innervate skin over the lateral surface of the thigh

Question 13

Describe the route of the lateral cutaneous nerve of the thigh to enter the thigh

Answer 13

Crosses iliac fossa in front of iliacus and enters the thigh behind the inguinal ligament

Question 14

Where does the femoral nerve originate?

Answer 14

L2 - L4

Question 15

What is the sensory and motor function of the femoral nerve?

Answer 15

Innervate muscle and skin at the front of the thigh

Question 16

Where does the obturator nerve originate?

Answer 16

L2 - L4

Question 17

How does the obturator nerve leave the pelvis?

Answer 17

Passes through obturator foramen into thigh

Question 18

What is the sensory function of the obturator nerve?

Answer 18

Innervate skin on the medial surface of the thigh

Question 19

What is the motor function of the obturator nerve?

Answer 19

Give branches to adductor group of muscles in thigh

Question 20

Where does the genitofemoral nerve originate?

Answer 20

L1 - L2

Question 21

What are the 2 branches of the genitofemoral nerve?

Answer 21

1. Genital

2. Femoral

Question 22

Where does the genital branch of the genitofemoral nerve supply?

Answer 22

Motor function to cremaster muscle

Question 23

Where does the genital nerve pass after the genitofemoral nerve divides?

Answer 23

Spermatic cord in males / Inguinal canal in females

Question 24

Where does the femoral branch of the genitofemoral nerve supply?

Answer 24

Sensory function to a small area of skin of the thigh