Basic anatomy of the spine Flashcards
Roughly how long is the spine?
70-75 cm long - accounts for 42% of height
What is the key benefit of the vertebral bones being joined by ligaments?
It makes it highly flexible and very strong
What are the gross functions of the vertebral column?
Centre of gravity of the body Attachment of bones Attachments for trunk muscles Protection and passage of the spinal cord Segmental innervation of the body
In terms of bone attachment, what is the importance of bones attaching above, centrally and below?
Above- bears support of the head
Centrally - supports the ribs and indirectly supports the upper limbs
Below - articulates with the hip bones, together with the hip bones they bear most of the weight of the body
When anterior curvature is exaggerated, what is this called?
Kyphosis
What is the functional significance of the spines sinusoidal profile?
In young adults it forms it a stretched “s” shape
This sinusoidal profile gives the column great flexibility and resilience
What is the significance of the imaginary line that forms the centre of gravity?
It crosses the sinuous bends of the vertebral column at vertebral levels
C1 and C2
C7 and T1
T12 and L1
L5 and S1
These points also happen to constitute natural weak points of the column
What happens to the vertebral column in old age?
The secondary curvatures tend to start to disappear - the fully continuous primary curvatures re-establish
What are the two types of assemblies of the vertebral column?
Discrete single vertebrae
- 24 separate vertebrae
- all capable of individual movement
Fused vertebrae
- 9 vertebrae fuse to give 2 innominate structures - sacrum (fusion of 5) and coccyx (fusion of 4)
What does a typical vertebra consist of?
Vertebral body - anteriorly
Vertebral arch or neural arch - posteriorly
In between them they enclose the spinal canal or vertebral foramen
What are the 3 processes of the vertebral arch?
Spinous process - midline and posterior
Transverse processes - laterally - 1 on each side of midline
What are the elaborations of the vertebral arch found on the superior surface?
Pedicle - part of neural arch between the body and the transverse process
Lamina - part of the neural arch between the transverse process and the spinous processes
What are the elaborations of the vertebral arch found on the supero-lateral view?
Articular processes - at the junction of the lamina and pedicle, articular facets are found
1 above and 1 below
Lined with cartilage
Allow for synovial joints to be formed between neural arches of adjacent vertebrae
Further strengthened by ligamentum flavum
What type of joint are facet joints?
They are of the synovial variety - joining two successive vertebra
Prevent anterior displacement of vertebrae
Allow for limited movement
Can bear weight when upright
What is the difference between primary and secondary cartilagenous joints?
primary can ossify whereas secondary can’t
