Spine Learning Objectives

Question 1

List the structural components of a typical vertebra and describe their function.

Answer 1

Anterior
	Vertebral body (support of body weight)

Posterior
Pedicle*
Superior articular process (restriction of movement)
Inferior articular process (restriction of movement)
Lamina*
Spinous process (muscle attachment and movement)
Transverse process (muscle attachment and movement)

Vertebral foramina (arch: protection of spinal cord)

Superior / Inferior notches

Question 2

Discuss the changes in vertebrae with advancing age.

Answer 2

Decrease in bone density
Articular surfaces bow inward
Compression at periphery
*Osteophytes form in response

Question 3

Summarize the development of spinal curvatures.

Answer 3

Primary curvatures (born with these; kyphosis)

• Thoracic
• Sacral

Secondary curvatures (developmental stages; lordosis)

• Cervical (develops when infant begins to stabilize weight of head)
• Lumbar (develops when toddler begins to support weight of body when learning how to walk)

Question 4

Define terminology for abnormal curvature of the spine.

Answer 4

Excessive kyphosis - usually thoracic spine level; characterized with forward protruding head and hump at superior thoracic spine

Excessive lordosis - typically at lumbar spine; seen with strong hip flexors (gymnasts) or pregnant women

Scoliosis - frontal plane; lateral deviation

Question 5

Describe the components of the intervertebral disc.

Answer 5

Account for 20-25% of vertebral column length

Anulus fibrosus (crossing fiber system; finger trap; maintains position of nucleus pulposus)
Nucleus pulposus (central)
Hyaline cartilage end plate

Question 6

Describe posterolateral herniation of the intervertebral disc.

Answer 6

Breakdown of anulus fibrosus
Extrusion of nucleus pulposus
Most commonly extrudes in posterolateral direction
Enters intervertebral foramen
Compresses spinal nerve (typically a level below herniation)

Question 7

List the six ligaments of the spine and describe the motions they limit.

Answer 7

Anterior longitudinal ligament:

• attachments- to anterior surfaces of vertebral bodies and intervertebral discs
• function- stabilizes vertebral column and prevents hyperextension

Posterior longitudinal ligament:

• attachments- to posterior surfaces of vertebral bodies and intervertebral discs
• function- prevents hyperflexion of the vertebral column

Ligamentum flavum:

• attachments- interconnect adjacent laminae
• function- resist terminal flexion between vertebrae

Supraspinous ligament:

• attachment- connects tips/apices of spinous processes C7 to sacrum

Interspinous ligaments:

• attachments- interconnect adjacent spinous processes

Intertransverse ligaments:

• attachments- interconnect adjacent transverse processes

Question 8

Discuss the structure of the ligamentum nuchae and its function.

Answer 8

Nuchal ligament

attachments- from C7 spinous process to external occipital protuberance with slips to intervening spinous processes

function- attachment for splenius capitis (and other cervical muscles)

Dense

Sagittal septum (median fibroelastic septum; wall separating right and left posterior neck)

Question 9

List the six primary movements of the spine and discuss how the amount of motion differs between regions of the spine.

Answer 9

Movements:

• extension
• flexion
• lateral extension (return to midline)
• lateral flexion (away from midline)
• rotation of head and neck
• rotation of upper trunk

Amount of motion: see chart in slides

Flexion and extension (sagittal plane)

• most movement in cervical spine
• less movement in thoracic spine
• significant movement in lumbar spine

Axial rotation (transverse plane)

• significant at C1-C2 level
• not much anywhere else in spine

Lateral flexion (frontal plane)

• most in cervical spine and lumbar spine
• limited in thoracic spine

Question 10

Describe the organization, attachments, and innervation of the extrinsic and intrinsic muscles of the back.

Answer 10

Extrinsic - superficial - CN XI, ventral rami
(Axio-appendicular)
- Trapezius
- Latissimus dorsi
- Levator Scapulae
- Rhomboids

Extrinsic - intermediate layer - intercostal nn.

• Serratus posterior superior
• Serratus posterior inferior

Intrinsic - superficial - dorsal rami

• splenius capitis
• splenius cervicis

Intrinsic - intermediate - lateral br./dorsal rami spinal nn.
(Erector spinae)
- Spinalis (thoracis, cervicis, capitis)
- Longissimus (capitis, cervicis, thoracis)
- Iliocostalis (cervicis, thoracis, lumborum)

Intrinsic - deep - dorsal rami of spinal nn.
(Transversospinales)
- Semispinalis (capitis, thoracis, cervicis)
- Multifidus
- Rotatores (longus, brevis)

• Interspinales (proprioception)
• Intertransversarii (proprioception)

Question 11

Describe the meningeal covering of the spinal cord.

Answer 11

Dura mater

Arachnoid mater
(Bonded to inner dura in vivo)

Pia mater
(Denticulate ligaments: pass through arachnoid mater to attach to dura mater to limit spinal cord movement)

Question 12

Describe the structural changes and clinical findings of spinal stenosis.

Answer 12

Narrowing of vertebral canal. (how/why?)

Can occur at all levels of the spinal column.

May cause compression of one or more of the spinal nerve roots occupying the inferior vertebral canal