L2.3 - Spine & Back

Question 1

Why do disc bulges occur posteriorly?

Answer 1

Less lamellae posteriorly - occurs when flexed & rotated.

Question 2

What plane do zygo. joints sit in for lumbar vertebra? Why does it change at L5?

Answer 2

Sagittal. Changes to coronal to stop it sliding off sacrum.

Question 3

What part of the sacrum is palpable?

Answer 3

Sacral cornu - also used in epidural anaesthetic

Question 4

When does spinal cord end?

Answer 4

L1/2, the conus medullaris

Question 5

After conus medullaris, what does the pia mater continue as?

Answer 5

Filum Terminale

Question 6

Dura and arachnoid mater continues till what level?

Answer 6

S2

Question 7

Where is the cauda equina found?

Answer 7

Between end of cord (L1/2) to (S2) - this space is filled with CSF (Lumbar cistern)

Question 8

Will disc bulge in L4/5 affect L4?

Answer 8

No as nerve root leaves above the disc

Question 9

*Innervation of Vertebral column?

Answer 9

Recurrent meningeal nerve

• Outer 1/3 of IVD
• Anterior dura
• PLL

Posterior ramus (smaller than anterior)

• Zygo joints
• Deep muscles of back
• Skin of back

Question 10

PLL is thickest at ____and weakest at ___

Answer 10

Midline, post. lateral part

Question 11

*5 Segmental ligaments

Answer 11

Intertransverse, interspinous, supraspinous, ilolumbar, ligamentum flavum (runs b/n lamina)

Question 12

*What does the thoracolumbar fascia do

Answer 12

It separates extrinsic and intrinsic back muscles, attaching to TA laterally.

Question 13

Erector spinae muscles

Answer 13

Iliocostalis, longissimus, spinalis

Question 14

Transversospinalis muscles

Answer 14

Semispinalis, multifidous, rotatores