Anatomy Block 3: Lumbar Plexus

Front 1

Subcostal Nerve
1. Where it originates
2. What muscles it runs across, pierces
3. What it provides sensation to

Back 1

1. T12
2. Runs across quadratus lumborum and pierces the transversus abdominus
3. Provides sensation to abdominal wall, below the navel, and above the pubic symphesis

Front 2

Iliohypogastric N
1. Origin
2. Runs with what n?
3. Runs under what m, across what m and transverses what muscle?
4. Supplies what muscles and skin area?

Back 2

1. Originates from L1
2. Runs with ilioinguinal n,
3. Runs under psoas major, runsacross quadradus lumborum and transverses abdominus
4. Supplies m and skin above superficial inguinal ring

Front 3

Ilioinguinal N
1. Origin
2. Runs with what n?
3. Runs under what m, across what m and transverses what bone?
4. Runs through what cord and supplies what skin area?

Back 3

1. L1
2. Runs with iliohypogastric n
3. Runs under psoas major m, across quadradus, and along the rim of ilium
4. Runs through inguinal ring and supplies the upper and medial part of the thigh (genitalia)

Front 4

Genitofemoral
1. Origin
2. What m does it pierce? Then run on top of as it splits into the 'A' portion and the 'B' portion?
3. The A is the motor nerve going through the ? to the ? muscle
4. The B runs underneath the ? and supplies sensation to this skin area.

Back 4

1. Originates at L1 and L2
2. It pierces the psoas m and runs on top and splits into the A) Genital Portion and B) Femoral Portion
3. The genital portion is the motor n going through the inguinal ring to supply the cremaster m
4. The femoral portion runs under the inguinal ligament and supplies sensation to the thigh.

Front 5

Lateral Cutaneous Nerve of Thigh
1. Origin
2. Under what muscle does it run, across the ? m., and under the ? ligament
3. what skin area does it supply?

Back 5

1. L2 to L3
2. Peaks from under the psoas m., across the iliacus m, and underneath inguinal ligament
3. Supplies cutaneous skin of the thigh.

Front 6

Femoral N (usually the largest n in plexus)
1. Origin
2. Travels under what m., under what lig, to what m?
3. It supplies what muscle that allows you to extend your leg?

Back 6

1. L2 to L4
2. Travels under the psoas m., under inguinal lig, to front of thigh
3. Supplies quadracepts m, allowing you to extend your leg

Front 7

Obturator N
1. Origin
2. Runs ? to the psoas m and through the ?
3. It supplies what generalized mm of the legs?

Back 7

1. L2 to L4
2. Runs medial to psoas m muscle, goes through opturator foramen (hole in hip)
3. Adductors of leg