Session 7 Cervical and thoracic spine Flashcards
which are the atypical vertebrae
C1, C2 and C7
Key characteristics of typical cervical vertebrae
Triangular vertebral foramen
Bifid spinous process (except 7)
Transverse foramen
Articular facets
Different orientation of facet joints
Cervical - 45 degree to axial plane
Thoracic- 60
Lumbar- 90
Key features of C1
Atlas
Widest cervical vertebra
No vertebral body or spinous process
Vertebral arches are thick and strong
Site of attachment of anterior longitudinal ligament
Anterior arch of C1 Atlas
Articulation of facets on C1
Superior- occipital condyles of skull
Inferior- superior articular facets of C2
What does the atlanto-occipital joint do
permit nodding and contribute to 50% of ROM for flexion and extension of head and neck
What does the Atlanto-axial joint do
Permit 50% of total rotation of head and neck (atlas and axis)
What is C2
Axis, provides pivot for atlas to rotate
Strongest cervical vertebra
Large spinous process
What is the odontoid process
Dens- projects vertically upwards from body of axis
Vestigial remnant of body of C1
Held in place by transverse ligament and acts as pivot joint
What prevents horizontal displacement of atlas on axis
odontoid process and transverse ligament
What is atlantoaxial instability
excessive movement between C1 and C2
What is the vertebra prominens
C7 -longest spinous process, not bifid
Large transverse process but transverse foramen in small and only transmits the accessory vertebral veins
Where in the cervical region is the groove for the spinal nerve
superior aspect of vertebral pedicle and between tubercles of transverse process
Spinal nerve passes posterior to the
vertebral artery (ascends through transverse foramen in C1-C6 together with vertebral vein and sympathetic plexus)
In lumbar spine, the exiting nerve crosses the
lateral aspect of the intervertebral disc
In lumbar spine, the spinal nerve exits through the
superior part of the intervertebral foramen
Where does each spinal nerve exit in cervical spine
Above its respectively named vertebral body (except C7/T1 where C8 exits above T1)
Important point in cervical spine disc prolapse
No traversing nerve root so exiting nerve root is compressed by the disc
What is ligamentum nuchae
thickening of supraspinous ligament
From occipital protuberance to spinous process of C7
What attaches to the posterior tubule of the atlas and the spinous process of all 7 cervical vertebrae
Fibrous lamina
Roles of ligamentum nuchae
Maintain secondary curvature of cervical spine
Assist it to support weight of head
Continuity with suprasinous ligament of thoracic and lumbar spine, major site of attachment of muscles in neck and trunk
Posterior longitudinal ligament runs from
body of axis to sacral canal
Main clinical relevance of posterior longitudinal ligament
Intervertebral disc prolapse tends to occur lateral to it
Cervical spine permits
45 degrees of lateral flexion at facet joints
How many thoracic vertebrae
12
Key characteristics of thoracic vertebrae
Heart shaped vertebral bodies
Small circular vertebral foramen
Prominent transverse processes with costal facets for articulation with ribs (not t11 and 12)
Demi facets or whole facets for articulation with head of ribs
Long spinous processes angulated inferiorly
Articular facets
Why does the thoracic spine have limited flexibility
Rib cage is connected to each segment
Ribs connected to T11 and 12 provide
protection for kidneys
Ribcage is made up of
Ribs, costal cartilage, sternum
What extra facets are in the thoracic spine
costal facets (articulate with heads of ribs)
What is atypical about T1
Superior costal facet is not a demi facet, only vertebra to articulate with 1st rib
what is atypical about T9 and T10
Whole costal facets articulate with 9th and 10th rib respectively
what is different about T11 and T12
Whole Costal facets are located on the pedicles
What happens to spinous processes down thoracic spine
less oblique and shorter
Where do the superior and inferior demi facets articulate with
head of rib adjacent and below
Facet joints permit
lateral flexion and rotation
Key characteristics of lumbar vertebra
large kidney shaped vertebral body Triangular shaped vertebral canal Large blunt transverse processes Short blunt spinous processes Facet joints 90 degrees to axial plane (permit a large range of flexion and extension)
