Spine - Ligaments, intervertebral discs, and thoracic cage

Question 1

What are the two 3 layered ligaments that descend along the spinal cord, front and back? Where do they attach/located? What are their functions?

Answer 1

Anterior Longitudinal ligament
- Descends along anterior and lateral surfaces of the vertebral bodies and attaches to the annulus fibrosus

Function: Prevents hyperextension and reinforces the anterior aspect of the sacrum

Posterior Longitudinal ligament
- Descends along the posterior surface (vertebral canal) of the vertebral bodies and intervertebral discs. It attaches to the annulus fibrosus

Function: Reinforces the posterior aspect of the sacrum

Question 2

Name/describe the ligaments that are located in the posterior aspect of the spinal cord?

Answer 2

Ligamentum Flava
- Strongest spinal ligament. It is located anterior to the interspinous ligament between the laminae of each vertebrae from the base of the skull to the pelvis

Function: Protects the spinal cord and binds the laminae of the adjacent vertebrae together. Prevents hyperflexion

Interspinous Ligament
- Located from the root to the apex of each spinous process and joining the ligamentum flava anteriorly and the supraspinous ligament posteriorly

Function: Stabilizes lumbar vertebrae, limits hyperflexion, and reinforces the posterior aspect of the sacrum

Supraspinous ligament
- Located at the tips of the spinous processes of the vertebrae from C7 to the sacrum. It is considered to be apart of the ligamentum nuchae in the cervical spine

Function: Limits hyperflexion

Intertransverse Ligaments
- Connects transverse processes from C7 to the sacrum

Function: Limits lateral hyperflexion and aids in vertebral stability

Ligamentum Nuchae
- Extends from the external occipital protuberance, down over the spinous processes of the cervical vertebrae. At the base of C7 this ligament continues as the cord-like supraspinous ligament

Function: Supports cervical spine and allows for flexion while resisting excessive movement

Question 3

What are the names a basic structures of the first two cervical vertebrae?

Answer 3

C1 - Atlas; articulates with the base of the skull at the ATLANTOOCCIPTAL JOINT. Has the facet for dens, where the odontoid process/dens articulates

C2 - Axis; articulates with the atlas at the ATLANTOAXIAL JOINT. It has the odontoid process that is held in place by the transverse ligament

Question 4

Where do arteries pass though the vertebrae?

Answer 4

The transverse foramen on either side of the spine

Question 5

What are the two costovertebral joints btw the ribs and the vertebrae?

Answer 5

1. Costovertebral joint
2. Costotransverse joint

Question 6

Describe the three components of a intervertebral disc. Superficial to deep

Answer 6

1. Annulus fibrosus - Inserts into the epiphyseal rim of the outer perimeter of the vertebral bodies (thinner posteriorly)

Function: Supports the vertebral column structurally. Oblique, adjacent layers of LAMELLAE fibers limit rotation and aid in strength

2. Nucleus Pulposus - Located in the center of the disc

Function: Acts as a shock absorber and permits very limited range of movement btw vertebrae

Question 7

How does disc pressure change?

Answer 7

Disc pressure increases lying down, to sitting, to standing. Disc pressure also increases leaning forward

Question 8

What are the two common disc pathologies ?

Answer 8

Herniated disc - annulus fibrosus is damaged enabling the nucleus pulposus to herniate

Degenerated disc - Spinal discs wear down/thin

Question 9

How many vertebrae are there? What are the divisons/numbers?

Answer 9

33 vertebrae

7 cervical
12 thoracic
5 lumbar
5 sacral (fused)
4 coccygeal (fused)

Question 10

What are the names of the spinal curves?

Answer 10

Thoracic and sacral curves are convex posteriorly - Kyphosis

Cervical and lumbar curves are concave anteriorly - Lordosis

Question 11

Which vertebrae have transverse foramen and a 45 degree anteroposterior facet joint?

Answer 11

Cervical vertebrae

Question 12

Which vertebrae have a 90 degree mediolateral facet joint, a broad and flat spinous process, and a small, triangular vertebral foramen?

Answer 12

Lumbar vertebrae

Question 13

Which vertebrae have a 60 degree anteroposterior facet joint, a long and slanted down spinous process as well as the only vertebrae with costal facets?

Answer 13

Thoracic vertebrae

Question 14

How many pairs of ribs are there? How many of each are true/false/vertebrochondral/floating?

Answer 14

12 pairs of ribs

7 pairs are true, attaching to the sternum via a separate costal cartilage

5 pairs are false ribs; 3 verebrochondral attaching via a shared costal cartilage; 2 floating (not attached)

Question 15

What are the three groups of muscles of the thoracic cage? Origin/insertions? Actions?

Answer 15

Diaphragm - Action is to depress and draw the central tendon forward in inhalation, reduces the pressure in the thoracic cavity, and increases pressure in the abdominal cavity

Internal intercostals - origin @ the longitudinal ridge on inner surface of ribs and costal cartilages and inserts @ the superior border of next rib below

Action: Elevates and depresses ribs

External intercostals - origin @ the inferior border of the ribs and inserts @ the superior border of the next rib below

Action: Elevates ribs during inspiration