week 7 Flashcards
Functions of the Vertebral Column
support upper body weight
protect spinal cord andnerves
allow trunk movement
Regions of vertebral column
Cervical-7 vertebrae
Thoracic-12 vertebrae
Lumbar-5 vertebrae
Sacral-5 fused vertebrae
Coccygeal-4 fused vertebrae
Regions/Bones of the vertebral column
Vertebral body
weight bearing
movement
Vertebral arch
protection
movement
Vertebral foramen/canal
passageway
Site of exit of the spinal nerves
Bounded by:
IV disc in front
bone of the pedicle above and below
Z joints behind
joints of the vertebral column
interbody joint- the intervertebral disc
- modified fibrocartilage joint
components:
cartilage end plate
annulus fibrosis
nucleus pulposus
structure of the IV disc
annulus fibrosis
- altering layers of dense regular connective tissue
nuscclus pulposus
- toothpaste like consistency
- end plate
cartilage disc
Cartilage end plate functions
transmits weight to adjacent vertebral body
confines nucleuspulposusand annulus fibrosis
role in securing nutrition for disc
annulus fibrosis functions
retain the nucleuspulposus
allow and limit movement
Nucleuspulposus functions
shock absorber–rapidly applied loads are temporarily diverted into bracing the annulusfibrosis
force distributor
Interbody joints characteristics
thickest in lumbar region
thinnest in upper thoracic region
-Avascular
Only supplied with nerves at their periphery
Contribute 25% of length of vertebral column
Lumbar
annulus fibrosis consists of alternatinglayers oriented 65º-70º to vertical
thicker anteriorly
Cervical
nucleuspulposusvery small and hasdisappeared by early adult life
annulus fibrosis develops horizontalfissures beginning in adolescence
Interbody joints functions
determine movement
contribute to normal vertebral curvature
Normal curvature of vertebral column
Functions to increase the shock absorbingfunction of the vertebral column
Thoracic/sacral regions =kyphotic(primary/structural) curve
Cervical/lumbar regions =lordotic(secondary/functional) curve
Z joint classification
synovial,multiaxial, plane
z joint articular suface
superior and inferiorarticularfacets
z joint articular capsule
loose but reinforced by:
ligamentum flavum
multifidus
z joint functions
to determine the direction of vertebral column movement
to determine the range of vertebral column movement
to bear weight (67% in cervical region, 15% in lumbar region)
cervical Vertebral column movements
Cervical region (C 3-7)
superiorarticularfacets tipped forward from the coronal plane
conjunct rotation-ipsilateralcoupling with lateral flexion
large range of flexion/extension -> intervertebral disc degeneration (fissuresin annulus fibrosis)
Vertebral column movements
Determined by “articulartriad”
interbodyjoint andzygapophysealjoints of eachvertebral level (segment)
flexion/extension
right and left lateral flexion
right and left rotation
Segmental range of movement small but total range large
Thoracic region Vertebral column movements
Thoracic region
superiorarticularfacets close to the coronal plane
equal range movements in all directions
all movements limited in range due to ribs
Lumbar region Vertebral column movements
“J-shaped” superiorarticularfacets in upper lumbar region (coronal andsagittalsections)
very, very limited rotation-sagittalportion
protection for intervertebral disc-coronal portion
Anterior longitudinal ligament
extends from C1 to sacrum attaching to anteriorsurfaces of vertebral bodies and discs
broad, strong
uter fibres span 3-4 segments, inner fibres span1 segment
limits extension
Posterior longitudinal ligament
extends from C2 to sacrum attaching toposterior surfaces of margins of vertebralbodies and discs
separated from vertebral bodies by venousplexus
weak and narrow in lumbar area
limits flexion
Ligamentum flavum
contains a significant amount of elastic tissue
connectslaminaeof adjacent vertebrae
passes from the posterior surface of the lamina of onevertebra to the anterior surface of the lamina of thevertebra above
attach to anterior part of capsule z joints
function to:
“brake” flexion
protect neural tissue
Supraspinous ligament
connects apices ofspinousprocesses fromC7 to sacrum
may be absent in low lumbar area
expands asligamentumnuchaeover cervicalarea
limits flexion
Interspinous ligament
connectspinousprocesses of adjacentvertebrae
limits flexion
Intertransverse ligament
connect transverse processes of adjacentvertebrae
limits lateral flexion
Atlas (C1)
No body – has two lateral masses united by
two arches
* Features:
1. Anterior arch with anterior tubercle
2. Posterior arch with posterior tubercle
3. Transverse processes with transverse
foramina
4. Superior articular facets
5. Inferior articular facets
6. Facet for dens (odontoid process)
Axis (C2)
- Body
- Spinous process
- Transverse processes with
transverse foramina - Superior articular facets
- Inferior articular facets
- Dens (odontoid process)
Craniovertebral joints
Involve occipital condyles,
C1 and C2
* Include:
* Atlanto-occipital joints
* Atlanto-axial joints
* 1x median
* 2x lateral
Atlanto-occipital joints classification
synovial, biaxial, ellipsoid (often considered a single joint)
- Articular surfaces: Atlanto-occipital joints
Superior articular facets of C1
* Occipital condyles of skull
- Articular capsules: Atlanto-occipital joints
thin and loose
Atlanto-occipital joints * Movements (of head):
Flexion and extension
* Lateral flexion and rotation –
coupled contralaterally
Atlanto-occipital joints – ligaments
anterior from anterior arch
of C1 to anterior margin of
foramen magnum
posterior from posterior arch
of C1 to posterior margin of
foramen magnum
- Limit
Flexion and extension - Lateral flexion and rotation –
coupled contralaterally
median atlanto-axial joint classification
Classification: synovial,
uniaxial, pivot
lateral atlanto-axial joints. Classification
synovial,
multiaxial, plane
(zygapophyseal joints)
median Atlanto-axial joints Articular surfaces:
Facet for dens on anterior arch of C1
* Dens of C2
* Transverse ligament of atlas
lateral Atlanto-axial joints Articular surfaces:
Inferior articular facets of C1
* Superior articular facets of C2
- Transverse ligament of atlas
Spans between two lateral masses of C1
* Wraps posteriorly around the dens of
C2 to hold it in place against the
anterior arch of C1
* Limits anterior glide of C1 during
flexion
* Has two longitudinal bands extending
from it
* Superior: to anterior margin of
foramen magnum
* Inferior: to posterior surface of
body of C2
- Apical ligament of dens
- From tip of dens to anterior margin of
foramen magnum - Anterior to superior longitudinal band of
cruciform ligament
- Alar ligaments
From tip of dens to medial sides of
occipital condyles
* Function: limit flexion, lateral flexion and
contralateral rotation of the head
- Tectorial membrane
Superior continuation of posterior
longitudinal ligament – from posterior
surface of body of C2 to anterior margin
of foramen magnum
* Posterior to cruciform ligament and alar
ligaments
* Function: limits flexion of the head
Anterior and posterior atlanto-axial
membranes
Anterior: from anterior arch of C1
to anterior surface of body of C2
* Posterior: from posterior arch of C1
to vertebral arch of C2
Ligamentum nuchae (nuchal ligament)
Not a “true” ligament of the neck
* Fibroelastic septum in the
midline of the posterior neck
* From spinous process of C7 to
occipital bone
* Superior continuation/expansion
of supraspinous ligament
Uncovertebral joints (joints of Luschka) classification
synovial
Uncovertebral joints (joints of Luschka) * Articular surfaces:
Lateral aspect of inferior
surface of vertebral body
above
* Uncinate process of vertebra
below
how do Uncovertebral joints (joints of Luschka) develop and what movements allow
- Develop as annulus fibrosus of
IVDs degenerate - Large range of movement
