Vertebral Column Flashcards
What are some functions of the vertebral column?
Centre of gravity for the body, attachment for bones and trunk muscles, protection and passage way for the spinal chord, has a role in posture and movement, provides segmental innervation for the body
What movements can the vertebral column perform?
Flexion
Extension
Rotation
Abduction
General features of the vertebral column
Forms the central axis
70-75 cms long
Made by a series of small bones which are joined together by cartilage and ligaments and it allows for flexibility
Describe the general structure of the vertebrae
Has a vertebral body and a vertebral arch
In the vertebral arch it has the spinous process, 2 transverse process and 2 articular process. It also has the vertebral foramen. The spinous process is attached to the transverse process via lamina and the transverse process is attached to the vertebral body by the pedicle.
The vertebral body is the weigh bearing structure. It increases in size as you go down the vertebral column. It’s lined with hyaline cartilage superiorly and inferiorly. The vertebral bodies are separated by intervertebral discs
Describe the structure of the intervertebral discs
It’s got the nucleus pulposus which is a remnant of the notochord and on the outside it has got annulus fibrosis
What are some features of the IV discs
Separate successive vertebrae
Joints are secondary cartilaginous joints
Presence allows for flexibility
Shock absorbers
Describe the structure of the annulus fibrosis
Made from a series of annular bands with baring orientation
Real shock absorber
Outer bands are collagenous and inner bands are fibro-collagenous
Very strong
Describe the structure of the nucleus pulposus
It’s jelly like
Has a high osmotic pressure
Located posteriorly in adults but centrally in children
Can herniate through annular fibrosis if there is degeneration ( slip disc )…This most commonly occurs in a posterior and lateral direction, putting pressure on the spinal cord, resulting in a variety of neurological and muscular symptoms.
Over time the nucleus can dehydrate which increases stress on the facet joints and lead to osteoarthritis of the facet joints at that level.
Describe the structure of the cervical vertebrae
There are seven cervical vertebrae in the human body. They have three main distinguishing features:
The spinous process bifurcates into two parts, and so is known as a bifid spinous process.
There are two transverse foramina, one in each transverse process. These conduct the vertebral arteries.( all except C7)
The vertebral foramen in triangular in shape
C7 does not have a bifurcated and it has a longer spinous process
Describe structure of the thoracic vertebrae
The twelve thoracic vertebrae are medium sized, and increase in size as they move down the back. Their main function is to articulate with ribs, producing the bony thorax.
Each thoracic vertebrae has two ‘demi facets‘ on each side of its vertebral body. These articulate with the head of the respective rib, and the rib inferior to it. On the transverse processes of the thoracic vertebrae there is a costal facet for articulation with its respective rib.
The spinous processes are slanted inferiorly and anteriorly. This offers increased protection to the spinal cord, preventing an object like a knife entering the spinal canal through the intervetebral discs.
In contrast to the cervical vertebrae, the vertebral foramen is circular. Also the vertebral body is heart shaped
Describe structure of the lumbar vertebrae
These are the largest of the vertebrae, of which there are five. They act to support the weight of the upper body, and have various specialisations to enable them do this.
Lumbar vertebrae have very large vertebral bodies, which are kidney shaped. They lack the characteristic features of other vertebrae, with no foramen transversarium, costal facets, or bifid spinous processes.
However, like the cervical vertebral, they have a triangular shaped vertebral foramen.
Describe the structure of the Sacrum
5 fused bones.
Triangular shaped, apex points inferiorly
On lateral surfaces are facets which articulate with ilium to form the sacro-illiac joint.
Describe the structure of the coccyx
4 fused bones
Articulated with the apex of the sacrum
No vertebral arches no vertebral canal does not conduct spinal chord
Describe the structure of C1
This is called the atlas
It articulates with the skull above to form the Atlanto- occipital joint and with the axis below to form the Atlanto- axial joint
It does not have a body or a spinous process
Fused with the axis to form the dens
Describe the structure of C2
It has got the dens
A large spinous process with is bifurcated
Rugged lateral mass
It is fractured or dislocated during hanging to give hangmans fracture
