Axial Skeleton: Joints of Vertebral Bodies/Arches

Question 1

What is Symphysis?

Answer 1

1. The binding tissue is a fibrocartilaginous disc
2. Adjacent vertebral bodies bound together by intervertebral disc
3. Contains the Anterior and Posterior longitudinal ligament

Question 2

What are the characteristics of the Intervertebral discs?

Answer 2

1. From C2 to L5 vertebrae
2. Increases in thickness as it descends (range of movement depends of the size)
3. Thicker in the cervical and lumbar vertebrae due to the Secondary curvatures

*Resist forces of compression and torsion

Question 3

What is Anulus fibrosus?

Answer 3

1. Outer layer of the Intervertebral disc
2. Concentric lamellae (layers) of fibrocartilage
3. Contains collagen fibers (Type 1)
4. Attaches to the smooth epiphysial rim around the edges of the superior and inferior surfaces of adult vertebral bodies

*Becomes less vascularized toward the center

Question 4

What is Nucleus pulposus?

Answer 4

1. The inner layer of the Intervertebral disc
2. Composed of:
   a. Type 2 collagen (jelly-like)
   b. Proteoglycan (attract a lot of water)
   c. Hyaluronic acid

*Attracts water molecules, hydrating the nucleus pulposus by osmotic swelling pressure effect

Question 5

What is collagen fibers in vertebral bodies?

Answer 5

1. Provides a strong bond between adjacent vertebrae

2. Allows limited rotation between vertebrae

Question 6

What is Epiphyseal rim?

Answer 6

1. Are formed by the fused anular epiphyses

Question 7

What is Anular epiphyses?

Answer 7

1. Zone from which the vertebral bodies grow in height
2. Are secondary ossification centers
3. Appear during adolescence; fused by 25 years old

Question 8

What is the function of Nucleus Pulposus?

Answer 8

1. Responsible for flexibility and resilience of IV disc/vertebral column
   * Water content declines over time due to the gradual loss of proteoglycans
   * Check height of a patient before 10am because there is a reduction in pressure borne of the disc during the day

Question 9

How does Nucleus pulposus receive nourishment?

Answer 9

1. Avascular

2. Receives nourishment by diffusion from blood vessels at the periphery of the anulus fibrosus and vertebral body

Question 10

What are 2 joints between C3 and

C7 on their posterolateral margin?

Answer 10

1. Uncovertebral (frequent site of spur formation that may cause neck pain)
2. Neurocentral (Luschka’s joints)

Question 11

What is the Uncovertebral joint?

Answer 11

1. Between C3 and C7
2. Have Uncinate processes (bony elevations on the superior margin of the cervical vertebrae)

• Sometimes considered a synovial joint; others believe it is a result from the degenerative process throughout age
• Bone spur formation occur with advance age, which cause neck pain

Question 12

What is an Uncinate processes?

Answer 12

1. Bony elevation on the superior margin of cervical vertebrae (C3 to C7)
2. Allow flexion and extension in the cervical vertebral column
3. Limits lateral flexion in the cervical VC
4. Important landmark in surgery because vertebral arteries lie lateral of the uncovertebral joint

Question 13

What is osteophytes?

Answer 13

1. Sites of bone spur formation

2. Causes neck pain

Question 14

What is the Anterior Longitudinal Ligament?

Answer 14

1. Connects the anterolateral aspects of the vertebral bodies and IV discs
2. Extends from the pelvic surface of the sacrum to the anterior tubercle of vertebra C1 and the occipital bone anterior to the foramen magnum
3. Prevents hyperextension of the VC, maintaining stability of the joints between the vertebral bodies

*Upper most part forms the Anterior atlanto-axial membrane (AAA) and Anterior atlanto-occipital membrane (AAO)

Question 15

What is the Posterior Longitudinal Ligament?

Answer 15

1. Narrower and weaker than the anterior longitudinal ligament
2. Located within the vertebral canal along the posterior surfaces of the vertebral bodies
3. Extends from the sacrum to C2 vertebrae where it becomes Tectorial membrane (TM)

• Weakly prevents hyperflexion
• Helps prevent posterior herniation of the nucleus pulposus

Question 16

What is the Tectorial membrane (TM)?

Answer 16

1. At the C2 vertebrae, which the top part of the posterior longitudinal ligament

Question 17

What are 3 parts of the vertebral arches?

Answer 17

1. Laminae
2. Transverse processes
3. Spinous processes

• Are connected by ligaments including:
  a. Ligamenta flava
  b. Interspinous and supraspinous ligaments
  c. Intertransverse ligaments
  d. Ligamentum nuchae

Question 18

What is the Zygapophyseal Joints?

Answer 18

1. Joints between the superior and inferior articular processes of adjacent vertebrae
2. Each joint is surrounded by a thin joint capsule (Allows gliding movement)

• Range of movement depends on the size of the IV disc
• Seen as synovial joints

Question 19

What is the Ligamenta flava?

Answer 19

1. Connect laminae of adjacent vertebrae, from C2 to S1
2. Consist of a yellow elastic tissue (thicker in the lumbar region; thinner in the cervical region)
3. Becomes the Posterior atlanto-axial membrane and Posterior atlanto-occipital membrane

Question 20

What is the function of the ligamenta flava?

Answer 20

1. Prevent separation of the laminae by limiting abrupt, sudden, excessive hyperflexion, which prevents injury on the IV discs
2. Help preserve the normal curvatures of the VC and upright posture
3. Assist with straightening of the column after flexing

*C1 (atlas) doesn’t have a lamina, which is why the ligamenta flava starts at C2

Question 21

What is the Interspinous ligaments?

Answer 21

1. Connects adjoining spinous processes (in between the spinous processes)
2. Thin spinous tissue

Question 22

What is the Supraspinous ligament?

Answer 22

1. Strong fibrous cord that connects the tips of the spinous process from C7 to the sacrum
2. Merges superiorly with the ligamentum nuchae

Question 23

What is the Ligamentum nuchae?

Answer 23

1. A strong fibroelastic membrane that forms a median band
2. Extends from the external occipital protuberance and posterior border of the foramen magnum to the spinous processes of the cervical vertebrae
3. Site of muscular attachment for muscles that attach to the spinous processes

*Strong median ligament of the neck

Question 24

What is the Intertransverse ligaments?

Answer 24

1. Connect adjacent transverse processes

Question 25

What are the boundaries of the Intervertebral foramina?(What makes up the vertebral foramen?)

Answer 25

1. Vertebral bodies and IV discs form the anterior boundary
2. Superior and Inferior vertebral notches form the top and bottom of the vertebral foramen
3. Zygopophysial joints and the Ligamenta Flava create the posterior boundary

Question 26

What Spondylolysis?

Answer 26

1. Fracture of the pars interarticularis
   * Pars interarticularis is part of the lamina (Connects the superior and inferior articular process)
   * In x-ray: The pars interarticularis (neck) looks like a dog with a collar around its neck. (scotty dog)

Question 27

What causes Spondylolysis?

Answer 27

1. Genetics- When the vertebral body and vertebral arches fail to fusion during development
2. Repeated trauma or hyperextension of lumbar spine (gymnasts, weight lifter, tennis players)
3. Degenerative disease- Arthritic changes in vertebral joints and cartilage degeneration

Question 28

What is Spondylolisthesis?

Answer 28

1. A vertebra slips forward or backward compared to the next vertebra