Cervical Spine Anatomy Flashcards
Upper cervical spine levels
Occiput-C2
Lower cervical spine levels
C2-C7
Orientation of Atlas
Anterior, medial, superior
What allows more atlanto-occipital extension?
oprientation of superior facets (ant, med, sup)
What is the first palpable midline structure below occiput
Axis spinous process
Structure that extends just superiorly above axis
Dens
What makes the dens susceptible to frx?
hypodense below dens
What type of joint– occipito-Atlantal
condyloid synovial joint
Occipito-atlantal joint CC/CV rules…
CC superior facets of C1 articulate with CV occipital condyles
Roll and slide opposite (CV on CC)
where is the OA joint capsule thick?
posterior lateral
What type of joint is the AA joint
Median (atlanto-odontoid) joint
-pivot synovial joint
-odontoid (dens) rotates in an osteoligamentous ring
2 lateral synovial joints AA CC/CV
C1 CV
C2 CV
gives a lot of mobility / rotation (50% occurs here) NOT congruent
large loose capsule
Which ligaments prevent anterior displacement of vertebral body of C1 on C2
Transverse and cruciform
Which ligaments limit AA flexion
transverse and cruciform
Which ligament holds the dens of the axis to the atlas?
transverse
Which cervical ligaments provide sagittal plane stability
transverse/cruciform
Which cervical lig. hold dens to the medial aspect of the occipital condyles
Alar
Orientation of the Alar Lig
sup, post, lateral (varies)
What does Alar ligament limit?
flexion, CL rotation and SB
prevents distraction of C1 on C2
Continuation of ALL lig
From C2 to the occiput (ant foramen magnum)
Anterior surface of C1 and C2
Ant atlantooccipital membrane (btwn OA) & ant atlantoaxial ligament (btwn AA)
– within the spinal canal on the posterior surface of the C1 and C2
– continuation of the PLL lig
tectoral membrane
What does the tectorial membrane limit?
– limits upper cervical flexion and holds the occiput off the atlas
continuation of the ligament flava
from C2 to the occiput (posterior foramen magnum)
post atlanto-occipital membrane and post atlanto-axial ligament
Rectus Capitus Post Major
actions:
capital ext
ipsilateral lateral flexion
Rectus Capitus Posterior Minor
actions:
Capital (AO) extension
ipsilateral lateral flexion (minimum)
Oblique capitus superior
actions:
capital AO extension
ipsilateral lateral flexion and rotation
Oblique capitus inferior
actions:
capital AA extension
ipsilateral lateral flexion and rotation
segmental stabilizer and provide proprioception
MF
Rectus Capitus Anterior
is deep to….
OI?
Action?
deep to longus capitus
anterior C1 lat mass to base of occiput
CV flexion
Rectus Capitus Lateralis
OI?
Action
C1 TP to occiput
CV lateral flexion
a weak CV flexor when contracts BILAT
what does the uncinate process limit
rotation
Uncinate process is where?
Cervical PL VB
C2-C7 spine VB
transverse diameter is _____ than AP diameter and height
sellar sup surface: ____ med-lat and ____ ant-post
greater
CC
CV
Most commonly involved nerves
C5-6
Cervical TP has foramen for
vertebral a, vertebral v, and venous plexus
TP of Vertebral Arch
ANT tubercle:
longus capitus, longus colli, and scalenus anterior
TP of vertebral arch
POST tubercle
Splenius, longissimus cervicis, iliocostalis cervisis, levator scpaulae, scalenus medius/posterior
What joint bears most of axial loading
Zygapophyseal joint
C2-C7 ___degrees above horizontal
C7-T1 ___degrees above horizontal
45
10
Z joint
Superior Facets face…
inferior facets face…
superior and lateral
inferior and medial
Ant vs post cervical joint capsule
anterior is strong, post is weak
what does the cervical joint capsule limit?
extreme intervertebral motions
what is the cerv. joint capsule reinforced by?
MF, lig flavum (ant capsule)
Ligament
-sacrum to C2
-Narrow in upper cervical and wider in lower cervical
-Limits extension or excessive lordosis
ALL
Ligament?
-Within vertebral canal
-sacrum to C2
-broader and thicker in cervical region
-limits flexion and prevents disc protrusion
PLL
Ligament?
- btwn laminas
-sacrum to C2
-Extends laterally to cover z joint
-limits flexion
-maintains tension when head and neck are in neutral
Ligament Flavum
thickening of this ligament increases the liklihood of spinal nerve/root impingement
lig flavum
(spinal stenosis more common in c spine, disc more common in l spine)
where is lig flavum weakest?
mid cervical
Ligament?
-SP to SP posteriorly
-continuation of supraspinous lig, C7 to external occipital protuberance
Lig Nuchae
which lig pulls the vertebrae posteriorly during cervical flexion, limiting ant translation (limiting cervical flexion)
nuchae
ligament?
-btwn adj spinous processes
-not well developed in c region
limits flexion
interspinous lig
height of cervical disc
disc to body height ratio
central/peripheral portions are called
5-6mm
1:3
nucleus pulposis, annulus fibrosis
Degeneration of disc – characterized by…
newborns % h2o
child 14 yrs % h2o
70 yrs % h2
decline of hydrophilic properties
88
80
70
Splitting along the post aspect of the disc
(horizontal, disc is degenerated)
cervical cleft
Function cervical vs lumbar
axial rotation
weight bearing
Nucleus ar birth cervical vs lumbar
25% disc
50% disc
annular layers cervical vs lumbar
indistinct
distinct, 65 deg to vertical
Cleft cervical vs lumbar
posterolateral disc, horizontal
circumferential and radial
Height cervical vs lumbar
thin
thick
nerve supply cervical vs lumbar
outer 1/3 (> lumbar spine)
outer 1/3
Trapezius:
contracting unilaterally:
Contracting bilaterally:
produces extension, ipsilateral lateral flexion and contralateral rotation
extension
Splenius cervicis and capitis
contracting unilaterally:
Contracting bilaterally:
ipsilateral lateral flexion and rotation
extension (travels med to lat)
SCM sternal and clavicular head
Unilaterally-
Bilaterally-
ipsilateral lateral flexion and CL rotation
Flexes lower cervical and extends upper cervical spine
Scalenes attachments
ant, med
posterior
1 rib
2 rib
scalenes
if c spine is stabilized
if ribs are stabilized (contracting unilaterally / bilaterally)
raise the ribs, assisting breathing
Unilateral: ipsilateral flexors and weak CL rotators
Bilateral: weak lower cervical flexors
Longus capitis and colli (stabilizers)
lateral/anterior VB attachment! (function: nodding)
CV & cervical flexion
resist to compression of head
Often injured during hyperextension whiplash injury
