Lumbar Anatomy

Question 1

Cervical Spinal Nerve Segments

Answer 1

8 nerves (C1-C8)
Level of exit from Verebral Column

Question 2

Thoracic and Lumbar Spinal Nerve Segments

Answer 2

Thoracic 12 (T1-12)
Lumbar 5 (L1-L5)

Nerves T1-L5 pass through IV foramina inferior to corresponding vertebrae

Question 3

Sacral Spinal Nerve Segments

Answer 3

5 (S1-S5) S1-S4 branch into anterior and posterior rami w/n sacrum, rami pass through anterior and posterior sacral foramina

Question 4

Coccygeal Spinal Nerve Segments

Answer 4

1 (Co1) 5th sacral and coccygeal nerves pass through sacral hiatus

Question 5

Conus Medullaris

Answer 5

Distal end of spinal cord
Contains sacral and coccygeal spinal cord segments

Question 6

Lumbar Sacral Plexus 1st 5 nerves

Answer 6

1 Subcostal (T12)
2 Iliohypogastric (L1)
3 Ilioinguinal (L1)
4 Genitofemoral (L1-L2)
5 Lateral femoral cutaneous (L2-L3)

Question 7

Lumbar Sacral Plexus last 6 nerves

Answer 7

6 -7 Branches to psoas major and iliacus (L2-L4)
8 Femoral (L2-L4)
9 Accessory obturator (L3-4)
10 Obturator (L2-L4)
11 Lumbosacral Trunk (L5-5)

Question 8

Femoral Nerve

Answer 8

L2-L4

Question 9

1st 5 Sacral nerves

Answer 9

1 to lumbar plexus
2 superior gluteal
3 inferior gluteal
4 nerve to piriformis
5 sciatic

Question 10

Sacral Plexus Nerves 6-11

Answer 10

6 Quad femoris and inf glutes
7 Obturator internus and sup gemellus
8 Posterior femoral cutaneous nerve
9 Perforating Cutaneous nerve
10 Pudendal Nerve
11 Perineum and levator ani

Question 11

Superficial Extrinsic Muscle of low back

Answer 11

• Lat Dorsi

Question 12

Intermediate Extrinsic Muscle of Low Back

Answer 12

Serratus Posterior Inferior

Question 13

Deep Intrinsic Muscles of Low Back
Intermediate (Erector Spinae Group)

Answer 13

• Iliocostalis
• Longissimus
• Spinalis

Question 14

Deep Intrinsic Muscles of Low Back
Deep (Transverospinalis Group)

Answer 14

Semispinalis
Multifidus
Rotatores

Question 15

Answer 15

Question 16

Answer 16

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

Answer 20

Question 21

Answer 21

Question 22

Answer 22

Question 23

Muscles of Flexion

Answer 23

Bilateral Action of
Rectus abdominus
Psoas major
Gravity

Question 24

Muscles of Extension

Answer 24

Bilateral Action of
Erector Spinae
Multifidus
Semispinalis thoracis

Question 25

Muscles of Lateral Bending

Answer 25

Unilateral action of
Iliocostalis thoracis and lumborum
Longissimus thoracis
Multifidus
External and internal oblique
Quadratus lumborum
Rhomboids
Serratus anterior

Question 26

Muscles of Rotation

Answer 26

Unilateral Action of
Rotatores
Multifidus
Iliocostalis
Longissimus
External oblique in synch w/ opposite internal oblique
Splenius thoracis