Lumbar Plexus

Question 1

The lumbar plexus is located where?

Answer 1

deep within psoas major on the posterior abdominal wall

Question 2

The lumbar plexus is formed from _____ rami of ____ - ____.

Answer 2

ventral; L1-L4

Question 3

We are responsible for knowing 2 out of 6 branches. What are they?

Answer 3

1. Femoral n.

2. Obturator n.

Question 4

Femoral n. or Obturator n.:

from posterior divisions of L2-L4.

Answer 4

femoral n.

Question 5

Femoral n. or Obturator n.:

enters thigh deep to the inguinal ligament, lateral to femoral sheath, and divides into several branches

Answer 5

femoral n.

Question 6

Femoral n. or Obturator n.:

innervates muscles of anterior compartment of thigh (except tensor fascia lata)

Answer 6

femoral n.

Question 7

Femoral n. or Obturator n.:

1 of the branches supplies cutaneous branches to anterior thigh (name the nerve and the branch too)

Answer 7

femoral n.

saphenous n.

Question 8

Femoral n. or Obturator n.:

from anterior divisions of L2-L4

Answer 8

obturator n.

Question 9

Femoral n. or Obturator n.:

enters thigh through a gap in the obturator foramen (the obturator canal)

Answer 9

obturator n.

Question 10

Name the 2 divisions of Obturator n.

Answer 10

1. anterior division

2. posterior division

Question 11

Obturator nerve lies on which m.?

Answer 11

adductor brevis

Question 12

Femoral n. or Obturator n.:
innervates muscles of medial compartment of thigh (except hamstring part of adductor magnus) & provides cutaneous branch to medial thigh

Answer 12

obturator n.

Question 13

4 nerves to know in dissection on anterior thigh

Answer 13

1. femoral n.
2. obturator n.
3. anterior division of obturator n.
4. posterior division of obturator n.