Bones - Cervical Spine

Question 1

How many vertebrae are there in this section?

Answer 1

7

Question 2

Which vertebrae are atypical?

Answer 2

1, 2, and 7 (doesnt transmits the vertebral artery - only vein)

Question 3

Characteristic features of these vertebrae?

Answer 3

1) Bifid spinous process
2) Triangular foramen
3) Transverse foramen - transmits vertebral arteries, veins and sympathetic nerves.

Question 4

Atlas

Answer 4

No vertebral body

No spinous process

Two lateral masses - connected by an anterior and posterior arch.

Each mass has a superior and inferior articular facet.

Superior articular facets articulate with the atlanto-occipital joints.

Anterior arch - contains a facet for articulation with the dens.

Posterior arch - contains a groove for the vertebral artery and C1 spinal nerve.

Question 5

Axis

Answer 5

Identifiable by the dens - extends from the anterior portion of the vertebra.

Dens articulates with the atlas to form the medial atlanto-axial joint.

Axis has two superior articular facets that articulate with the inferior articular facets of C1 - two lateral atlanto-axial joints.

Question 6

Ligaments present throughout the entire vertebral column in the cervical segment?

Answer 6

1) Ligamentum flavum - connects laminae of adjacent vertebrae
2) Interspinous ligament - connects spinous processes of adjacent vertebrae
3) Anterior (prevents hyperextension) and posterior longitudinal ligaments (prevents hyperflexion).

Question 7

Ligaments unique to the cervical segment?

Answer 7

1) Nuchal ligament - a continuation of the supraspinous ligament. Attaches the spinous processes of C1-C7. Provides attachment for the rhomboids and trapezius.
2) Transverse ligament of atlas - connects lateral masses of the atllas, anchoring the dens in place. Strongest ligament in the spine.
3) Alar ligament - lateral margins of foramen magnum to the dens.
4) Apical ligament - anterior margins of foramen magnum to the dens.
5) Tectorium membrane - continuation of the posterior longitudinal ligament and joins the anterior foramen magnum.

Question 8

Clinical relevance - Jefferson’s fracture

Answer 8

Caused by fall on extended neck e.g. diving into excessively shallow water.

This causes compression of the lateral masses of the atlas between the occipital condyles and the axis.

This may result in the fracture of one or both of the anterior arches.

With enough force, the transverse ligament of atlas may be ruptured.

Unlikely to be damage of the spinal cord at C1 due to the large foramen, but it may be damaged further down the spine.