Session 5 - The vertebral column Flashcards
How are the vertebra held together?
-By ligaments
How many bones are in the vertebral column? How are these organised?
-33 bones; 24 discrete single vertebrae; 9 fused vertebrae
What are the gross functions of the vertebral column?
- Centre of gravity
- Attachments for bones of appendicular skeleton
- Attachment for trunk muscles
- Protection and passage of spinal cord
- Segmental innervation
What are possible movements of the vertebral column?
- Flexion
- Extension
- ABduction
- ADduction
- Rotation
How does the vertebral column act as the centre of gravity?
-The weight of the body is projected into the lower limbs about an imaginary line that passes centrally through the natural curvatures of the vertebral column
What bones does the vertebral column act as a site of attachment for?
- Skull
- Ribs (indirectly the upper limb)
- Hip bones (indirectly lower limb)
How is an upright posture maintained?
-Continuous low level contraction of trunk muscles to support the body weight
How does the vertebral column protect the spinal cord?
-Spinal cord runs through the spinal canal formed by successive vertebral foramen for its entirety
Describe the presentation of the vertebral column in the fetus
- A single flexed curvature which faces anteriorly (concave anteriorly)
- Known as primary curvature
-Where is the primary curvature maintained in the vertebral column thoughout life?
-Thoracic and sacral/coccygeal spine
What is kyphosis?
-An exaggerated anterior curvature
What is lordosis?
-An exaggerated posterior curvature
What is scoliosis?
-Lateral deviation of the backbone
Describe the presentation of the vertebral column in the young adult
-4 distinct curvatures arranged to give a sinusoidal shape
2 anterior curvatures (thoracic and sacral)
2 Posterior curvatures (cervical and lumbar)
What are posterior curvatures of the vertebral column also known as?
-Secondary curvatures
What characteristic does the sinusoidal profile of the vertebral column provide?
-Great resilience
How does the vertebral column change from that in a foetus to that of a young adult?
- Primary curvature becomes remodelled as the baby lifts the head, the primary curvature is replaced by a posterior curvature (cervical region)
- The lumbar spine is then remodelled during crawling and walking to form the second posterior concavity
Where are naturally weak points of the spine?
-C7/T1
-T12/L1
-L1/S5
Points of change in curvature
Describe the presentation of the vertebral column in old age
-Secondary curvatures start to disappear with the vertebral column seeming to return to its original shape in the foetus and a fully continuous primary curvature re-establishes
Name the fused vertebrae
- Sacrum (5)
- Coccyx (4)
Name the discrete vertebrae
- Cervical (7)
- Thoracic (12)
- Lumbar (5)
Which vertebrae are capable of individual movement?
-Discrete vertebrae
What are the two segments of discrete vertebrae?
- Anterior vertebral body
- Posterior vertebral arch
What part of the discrete vertebrae is the main weight-bearing?
-Vertebral body
How are adjacent vertebrae linked together?
-Through intervertebral discs which interdigitate with the vertebral body from C2/C3 to L5/S1 joints
What cartilage lines the vertebral body?
-Hyaline
How does the size of the vertebrae change throughout the discrete vertebrae?
-Increases from top-downwards
What three processes emerge from a vertebral arch?
- Two transverse processes laying laterally on either side of midline
- One spinous process at the posterior midline
What is the pedicle of the neural arch?
-The part of the neural arch between the vertebral body and the transverse process
What is the lamina of the neural arch?
-The part of the neural arch between the transverse and spinous processes
What are facets of the neural arch?
-Cartilage-lined articular processes which lie superiorly and inferiorly at the junction between the pedicle and the lamina
What do facets forms
-Synovial joints between successive vertebrae
What strengthens the facet joints between successive vertebrae?
-Ligamentum Flavum
What do facet joints prevent?
-Anterior displacement of vertebrae
Are facet joints weight bearing?
-Yes when upright
Where are the vertebral notches on the neural arch?
- One superior on pedicles
- One inferior on pedicles
What forms the interverebral foreman?
-Inferior vertebral notch of one vertebrae with the superior vertebra notch on the successive vertebrae on each side of the vertebral column