Osteology Flashcards
What are the major bones of the neck?
Cervical vertebrae
How many vertebrae are cervical?
7
What is C1 known as?
Atlas
What is C2 known as?
Axis
What are three distinctive features of cervical vertebrae?
1) Triangular vertebral foramen
2) Bifid spinous process
3) Transverse foramina (holes in transverse processes for vertebral artery, vein and sympathetic nerves)
Which are the atypical cervical vertebrae?
C1, C2, C7
Why is C1 atypical?
No vertebral body
No spinous process
Articular facet for dens
Groove for vertebral artery and C1 spinal nerve on posterior arch
Why is C2 atypical?
Has a dens which extends superiorly from the anterior portion of the vertebra, articulating with the atlas
Why is C7 atypical?
Non bifid spinous process
In which vertebrae does the vertebral artery etc not pass through the transverse foramina?
C7 - artery runs around vertebra, veins and nerves still pass through foramina
C1 - artery runs along the groove for the vertebral artery
What is a Jefferson fracture?
Fracture of C1
Vertical fall onto an extended neck - can compress lateral masses between occipital condyles and the axis, causing them to be driven apart and fracturing one/both of the anterior/posterior arches. Transverse ligament may also be ruptured
In a Jefferson fracture, why is it unlikely that there will be damage tot he spinal cord at the C1 level?
This is because the vertebral foramen is large
What is a Hangman’s fracture?
Fracture of the pars interarticularis - between superior and inferior articular facets of the axis
What is the neurocranium?
Formed by superior aspect of the skull - subdivided into calvarium (roof of skull) and cranial base
What makes up the calvarium?
Frontal, occipital and two parietal bones
What is the cranial base comprised of?
6 bones
Frontal, sphenoid, ethmomid, occipital, parietal and temporal bones