Vertebrae Flashcards
what are the 5 regions of the vertebral column?
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 4 coccygeal
which vertabrae are fused to form what structures in adults?
- the 5 sacral vertebrae are fused in adults to form the sacrum
- the 4 coccygeal vertebrae are fused to form the coccyx
what are the structural differences of the vertebrae in different regions related to?
- the size/structure is related to how much body weight they need to carry
- ie the vertebrae reach the max size towards the sacrum
what is the lumbosacral angle?
this is located at the junction of the lumbar region of the vertebral colum and sacrum
what are the 2 main curvatures of the spine?
- thoracic and sacral curvatures - Kyphoses - concaves anteriorly
- cervical & lumbarcurvatures (lordoses) concave posteriorly
what are primary curvatures?
give example
curvatures that develop during the fetal period
eg thoracic and sacral
why is the presacral region of the vertebral column so flexible?
consists of vertebrae that are joined together via intervertebral (IV) discs
what does a typical vertebrae consist of?
- vertebral body
- vertebral arch
- 7 processes
what is the function of the vertebral body?
- gives strength to the vertebral column & supports body weight
what is the vertebral arch formed from?
the left and right pedicles & lamina
what are the pedicles?
they are short, stout processes that join the vertebral arch to the vertebral body
what do the pedicles project posteriorly to come into contact with?
they project posteriorly to come into contact with laminae ( 2 broad pieces of flat bone)
what does the **succession of the vertebral foramen form **& what does it contain ?
forms the **vertebral canal **- which contains the spinal cord, meninges, spinal nerve roots and vessels
what are the vertebral notches?
they are indentations formed by the projection of the body & articular processes
what 7 processes arise from the vertebral arch of a typical vertebra?
- one median spinous process projects posteriorly
- 2 transverse processes projecting posterolaterally
- 4 articular processes - 2 superior & two inferior
what do the 4 articular processes contain?
an **articular surface - facet **
what do the spinous process & 2 transverse processes provide attachment for?
- they project from the vertebral arch and provide attachments for deep back muscles - serving as levers in moving the vertebrae
which are the atypical vs typical vertebrae of the cervical region of the vertebral column?
- atypical - **C1 (atlas) **& C2 (Axis) AND C7
- typical - C3-C6
Describe the regional characteristics of the typical cervical vertebrae
ie C3-C6
- small and wide vertebral body
- large and traingular vertebral foramen
also have transverse foramina - superior facets directed superoposteriorly
- IV discs are thick
what is the function of the cervical region?
supports the weight of the head
Describe the characteristics of C1 (atlas)
- no spinous process & no body
- ring like
what does the concave superior articular facet of C1 articulate with & as a result what joint does these 2 structures form?
- articulates with the occipital condyle
- called the atlantooccipital joint
what does the inferior articular facet of the C1 vertebrae articulate with ? and what joint does it form as a result?
- articulates with the superior facet of C2 (the axis)
- forms the atlantoaxial joint
Describe the characteristics of C2 (axis)
- strongest cervical vertebra
- has a distinctive ‘dens’ or the otontoid process
- the spinous process attaches to the nuchal ligament - a unique ligament in the cervical spine
what 2 cervical vertebrae contribute to 50% of cervical rotation?
- C1 - atlas
- C2 - axis
what is occipitalisation of the atlas?
- abnormality that occurs at the base of the skull
- results in a narrower foramen magnum
- therefore can compress the spinal cord or brain stem
what are the regional characteristics of the thoracic vertebrae?
- body is larger
- smaller vertebral foamen
- spinous process is long and fairly thick
they contain articular facets for the ribs
Describe the regional characteristics of the lumbar vertebrae
- largest body
- the spinous process is large and blunt
- missing articular facets for ribs
1 vertebral foramen
what is spina bifida?
- congenital disorder
- the laminae of L5 and or S1 fail to develop normally and fuse
what are IV discs & what is their function?
- they are strong attachments between vertebral bodies that permit movement between adjacent vertebrae
- also act as shock absorbes
what are zygopophysial joints?
joinst between the superior and inferior articular processes of adjacent vertebrae
what is a clinical point about the uncovertebral joints?
- they are frequent sites of spur formation (projecting processes of bone) - causing neck pain
what is the anterior longitudinal ligament?
- a strong, broad, fibrous band that covers & connects the anterolateral aspects of the vertebral bodies and IV discs
what are the 2 parts of the anterior longitudinal ligament?
- superficial - bridge between vertebrae
- deep - short, between each vertebrae
what is the posterior longitudinal ligament ?
- much** narrower and somewhat weaker band** than the ALL
- the ligament runs** within the vertebral canal** along the posterior aspect of the vertebral bodies
- from C2- sacrum
- the** short fibres attach to the IV disc**
what are the 3 accessory ligaments of the vertebral column?
- interspinous ligament
- intertransverse ligament
- ligamentum flavum
Describe the ligamenta flava
structure, function
- yellow elastic fibrous tissue
- connects laminae of the adjacent vertebrae
- helps to preserve posture
travels from C2-sacrum
Describe the intertransverse ligament along the different regions of the spine
ie cervical, thoracic, and lumbar
- cervical - scattered / irregular fibres
- thoracic- form more distinct bands - blend with muscle
- lumbar - well developed but thin
what is the transverse ligament?
- located in the atlas
- strong band anchoring dens to ring of atlas
- provides C1 and C2 with stability
Describe the cruciate ligament
- together the transverse ligament and the longitudinal bands form the cruciate ligament
Describe the atlanto-occipital joint
- located between the **lateral masses of C1 (atlas) and the occipital condyles **
- permit nodding of the head
- ie flexion and extension of the head
Describe the atlanto-axial joint
- there are 3 joints
- 2 median AAJ for rotation movement
- 1 lateral AAJ for gliding movement
what is a jefferson fracture?
- fracture of C1
- main mechanism is by placing a bar or weight on shoulders
what are odontoid fractures?
- fractures of C2
- mainly due to trauma
- unstable fracture - may need surgical intervention
- can happen via hyperextension, hyperflexion etc
what is hangmans fracture?
- bilateral fracture of C2
- common mechanism - hyperextension, axial loading , contact sports etc
what is a clinical marker of C spine trauma?
prevertebral soft tissue swelling (PSTS)
what blood vessels are the vertebrae supplied by?
think of layers of dura matter - outer layer name
- the periosteal and equatorial branches of the major cervical and segmental arteries and their spinal branches
what are the 2 spinal venous plexus’ ?
- internal vertebral epidural venous plexus
- external vertebral venous plexus
what are the basivertebral veins?
- form within the vertebral bodies, emerge from the foramina and drain into both venous plexuses
what is the vertebral column innervated by?
- meningeal branches of the spinal nerves
- some of the meningeal branches run back into the IV foramen (recurrent) and some dont
- the ones that stay outside the canal innervate the ALL
- recurrent branches supply the ligamenta flava etc
describe the arterial supply of the vertebrae
-anterior spinal artery
-posterior spinal arteries - x2
-segmental arteries
