L10 - vertebral column Flashcards
how many vertebrae does the adult vertebral column have
33
how many cervical vertebrae are there
7
how many thoracic vertebrae are there
12
how many lumbar vertebrae are there
5
how many sacral vertebrae are there
5
how many coccygeal vertebrae are there
4
what holds the vertebrae together?
facet joints
intevertebral discs
ligaments
facet joints
connect the superior and inferior articular processes of adjacent vertebrae; interlocking maintains stability
intervertebral foramen
pathway in which the spinal nerves pass
role of ligaments
bing vertebrae together and stabilise the vertebral column
intervertebral disc
- between all non-fused vertebrae
- provide flexibility
- act as shock absorbers
- adhere vertebral bodies to one another
functions of vertebral column
- protect spinal cord
- support body weight
- semi-rigid axis for bodt
- allows for pivoting of the head
- supports posture and locomotion
spinal canal
tunnel formed by stacked up vertebrae in which the spinal cord passes through
primary curvature of spinal canal
thoracic and sacral kyphoses
secondary curvatures
cervical and lumbar lordoses
curvatures in babies
- in foetus, primary curvature forms uniformally
- as the baby grows and supports its own head and walks, the secondary curvatures form
scoliosis
curvature of the spine so that the vertebral column is not in the midline - lateral curvature
excessive kyphosis
hunch back
pedicles
segments of the vertebral arch
- join the spinous and transverse processes together
- join spinous processes the body
laminae
important for ligament attachment
superior and inferior articular processes
- form facet joints
- determines type of movement we have in our vertebral column
transverse processes
- articulate with ribs
spinous process
- connects directly out posterior
what do we feel in the midline of out back
spinous processes
smallest vertebrae
cervical
atypical features of C1
articulates with occiput
- allows us to nod our head up and down
atypical features of C1 and C2
C1 and C2 articulate with each other and form a pivot joint – allows us to turn our head from side to side
vertebra prominens
long spinous process on C7
transverse foramina of C7
small or absent
what do we feel at the bottom of our neck
vertebra prominens
how many cervical spinal nerves are there
8
why are injuries to C spine common
- C spine is flexible
- head is heavy
movements of C spine
- flex and extend
- laterally flex
- head rotation
bifid
splits into 2
which part of the cervical vertebrae is bifid
spinous
why does injury to the vertebral foramen not always affect the spinal cord
it is large compared to it
importance of transverse foramina
passage of vertebral artery and vein to and from brain
which foramina does the vertebral artery not travel through
C7
shape of C1
ring
- no vertebral body or spinous process
importance of articulation between C1 and skull
allows us to move our head up and down
atlantoaxial joints
between C1 and C2
how many atlantoaxial joints are there
3
- 2 lateral
- 1 median
lateral atlantoaxial joints
between the lateral masses of C1 and the superior facets of C2
medial atlantoaxial joint
a pivot joint between the dens and atlas
Synovial – which means it can be affected by RA
how is the atlantoaxial joint reinforced
transverse ligament of the atlas which holds the dens in place
what causes fracture of the atlas
axial loading –> can burst fracture of C1 ring
Jefferson fracture
fracture of atlas
cause of axial loading
any direct blow to the top of the head
- e.g., diving into a pool and hitting head on bottom
consequence of atlas fracture
- doesn’t always cause spinal cord injury
- wider vertebral foramen
- spinal cord is not compressed
how common is fracture of dens
10-15% of C-spine fractures
cause of fracture of dens
hyeprflexion of hyperextension
who is most affected by fracture of dens
- over 70s (low-energy trauma)
- 20-30s (high energy trauma)
how is the dens held in place
transverse ligaments of the atlas
is the spinal cord affected in a dens fracture
not usually
- dens held in place by ligaments
- spinal canal is much larger than spinal cord
however, if dens fractured and ligaments ruptures, dens may be driven into the brainstem
C-spine immobilisation
collar
blocks / plates
tape
lordosis
loss of normal curvature of spine
shape of thoracic vertebral body
heart shaped with superior and inferior costal Demi-facets
role of demi-facets in thoracic vertebrae
articulation with head of rib
spinous process of thoracic vertebrae
long and extends postero-inferiorly
transverse process of thoracic vertebrae
costal facet for articulation with tubercle of a ribe
articular facets of thoracic vertebrae
superior facets posteriorly
inferior facets anteriorly
most commonly affected areas for T-spine trauma
T11-12
osteoporosis
metabolic disease / demineralisation where bones become weak
compression ‘wedge; fracture
concavity of vertebral body (instead of them being square)
osteoarthritis
wear and tear at the joints
- osteophytes: joint narrowing
vertebral body of L vertebrae
large for increased weight bearing
articular facets of L vertebrae
- Superior face medially
- Inferior face laterally
spinous process of L vertebrae
short and sturdy
vertebral foramen of L vertebae
narrow
ala
transverse processes which have fused together on either side
movements of vertebral column
flexion
extension
lateral flexion (side to side)
rotation (look over shoulder)
most flexible vertebral levels
C and L
movement in T-spine
- flexion limited
- rotation possible
- as they articulate with rubs and ribs articulate with sternum
innervation of intrinsic muscles of back
posterior rami of spinal nerve
chief extensor or vertebral column
erector spinae
erector spinae
- Large muscle that runs longitudinally either side of VC
- Composed of 3 separate muscles
muscles which make up erector spinae
- longissimus muscle
- iliocostalis muscle
- spinalis muscle
what lies deep to erector spinae
smaller muscles
location of intervertebral discs
between vertebral bodies
what makes up intervertebral discs
outer = annulus fibrosus inner = nucleus pulposus
annulus fibrosus
Fibrocartilage ring attached to the rim of vertebral body
nucleus pulposus
Gelatinous ‘shock absorber’
role of intervertebral discs
flexibility, shock absorption and stability
slipped disc
when annulus fibrosus becomes stiff and nucleus pulposus herniates through, squashing the spinal nerve or spinal cord itseld
why are the C and L spine most flexible
intervertebral discs are thicker here
what happens to intervertebral discs with age
dehydrate
become thinner and stiffer
sciatica
compression of spinal nerve roots and L5/S1 or L5/S1
key ligaments in the vertebral canal
- posterior longitudinal ligament
- anterior longitudinal ligament
- ligamentum flavym
Posterior longitudinal ligament
- C2 to sacrum
- Resists hyperflexion
- Prevents posterior herniation of IV discs
Anterior longitudinal ligament
- Runs anterior to the vertebral bodies
- Longitudinal – runs from top to bottom
- Occipital bone and C1 to sacrum
- Only ligament to resist hyperextension of vertebral column, all the others resist hyperflexion
Ligamentum flavum (L. yellow)
- Binds lamina of adjacent vertebrae
- Traversed in LP; resistance felt against the needle before it ‘gives’ with a so-called “pop”
ligaments which bind spinous processes together
interspinous and supraspinous ligaments
interspinous ligaments
between adjacent spinous processes
Supraspinous ligaments
join the tips of the spinous processes
route of lumbar puncture
through the supra, through the infra, through the ligamentum flavum and into the vertebral canal
whiplash
Rapid, forceful hyperextension then hyperflexion
which ligament is torn in hyperextension
Anterior longitudinal ligament
