Joints of the Vertebral Column Flashcards
What type of joint are intervertebral discs part of?
Symphysis
Location of intervertebral discs
Between vertebral bodies from C2 to sacrum
Degenerate disc between S5 and Cx1
Intervertebral disc shape throughout the spine
- Thicker anterior>posterior in cervical & lumbar (creates spinal curvatures)
- flat in thoracic, thinnest in upper thoracic
- thickest in lumbar region
Intervertebral disc ligament attachments
- attached to ALL & PLL
- attached to heads of ribs via interarticular ligaments
Functions of annulus fibrosis
Enclose and retain nucleus pulposus
Absorb compressive shocks
Structural unit between vertebral bodies
Allows restricted motion
Describe zones of annulus fibrosis
Outer collagenous zone,
wider, inner fibrocartilage zone arranged in lamellae
annulus fibrosis
Fibers at adjacent
laminae are arranged…
obliquely at 30 degrees
from horizontal
annulus fibrosis
Oblique arrangement of fibers gives…
torsional strength to disc
The intervetebral discs are composed of:
nucleus pulposus and annulus fibrosis
Intervertebral discs adhere to…
Adhere to surface of vertebral body above & below via vertebral end plate with thin layer of hyaline cartilage
Function of nucleus pulposus
Resilient spacer allowing motion between vertebrae
Distributes compressive forces
Nucleus pulposis makes up how much bulk of disc?
40%
Nucleus pulposus is located more ____ than ____
Posterior>anterior
Describe changes to the nucleus pulposus throughout life
Larger at birth, decreases in size with age (dehydrates)
Notochordal cells disappear within first decade of life
What is the nucleus pulposis made of?
High water content, remains of notochord (mesoderm)
Innervation of posterior intervertebral disc
recurrent meningeal nerve
Innervation of posterolateral intervertebral disc
ventral rami
gray rami communicants
Innervation of anterolateral intervertebral disc
gray rami communicant
sympathetic trunk
What is a disc herniation?
Nucleus pulposus extrudes through a defect in annulus fibrosis
What direction is a disc herniation most likely to occur?
Posterolaterally
(Nucleus pulposus is located more posteriorly)
Disc herniation is most likely to occur…
- lumbar region (annulus is thinnest)
- posterolaterally (posterior longitudinal lig is directly posterior)
- under 55 years (less to bulge out with aging due to dehydration)
Vascularization of intervertebral discs
Avascular except for periphery
Zygapophyseal joints are what type of joint?
Plane synovial
Zygapophyseal joints are at what angle in the cervical region of the spine?
45 degrees
Zygapophyseal joints are at what angle in the thoracic region of the spine?
60 degrees
Zygapophyseal joints are at what angle in the lumbar region of the spine?
90 degrees
Zygapophyseal joints may contain what in lumbar region?
fat pads or fibroadipose menisci
Innervation of zygapophyseal joints
medial branches of dorsal rami, ascending branch of nerve below and descending of nerve above
Non-segmental syndesmoses of spine include:
ALL, PLL, supraspinous ligament, ligamentum nuchae
Non-segmental syndesmosis
Anterior Longitudinal Ligament (ALL) location and attachments
Anterior surfaces of vertebral bodies and IVDs (S5-C2)
Anterior longitudinal ligament is tense in ____
Extension
Anterior Longitudinal Ligament (ALL)
Between occipital and C1
atlantooccipital membrane
Anterior Longitudinal Ligament (ALL)
Between C1 and C2
atlantoaxial membrane
Non-segmental syndesmosis
Posterior Longitudinal Ligament (PLL) location and attachment
Lies in vertebral canal, attaches to vertebral bodies and IVDs (S5-C2)
Non-segmental syndesmosis
Posterior Longitudinal Ligament (PLL) is continuous with…
tectorial membrane above C2
non-segmental syndesmosis
Posterior Longitudinal Ligament (PLL) is broader in…
cervical and thoracic regions
Posterior longitudinal ligament is tense in ____
Flexion
non-segmental syndesmosis
In lower thoracic and lumbar regions, Posterior Longitudinal Ligament (PLL) is:
denticulated (broader over discs, narrow over bodies)
non-segmental syndesmosis
Supraspinous ligament
Strong fibrous cord connecting apices of spinous processes from C7 to sacrum
non-segmental syndesmoses
Between C7 and
occipital, the supraspinous ligament is replaced by:
ligamentum nuchae
Non-segmental syndesmosis
Ligamentum nuchae attaches…
from external occipital protruberance along median occipital crest, posterior tubercle of atlas, spinous processes of cervical vertebrae
non-segmental syndemosis
Ligamentum nuchae structure
Bilaminar, fibroelastic membrane
Homologous with supraspinous and interspinous ligaments
non-segmental syndesmosis
Ligamentum nuchae function
passively supports head, tensed in flexion
the following are examples of ____
Ligamentum Flavum
Interspinous Ligaments
Intertranvserse Ligaments
Accessory Ligament
Cruciate Ligament
Apical Ligament of Dens
segmental syndesmoses
segmental syndesmosis
Ligamentum flavum location
one pair between laminae of adjacent vertebrae (sacrum-C2)
segmental syndesmosis
Ligamentum flavum is composed of:
yellow elastic collagen
ligamentum flava
posterior atlantooccipital membrane location
between posterior arch of atlas and foramen magnum
ligamentum flava
posterior atlantoaxial membrane location
between posterior arch of atlas and laminae of axis
Ligamentum flavum include:
posterior atlantoaxial membrane
posterior atlantooccipital membrane
segmental syndesmosis
Ligamentum flavum function
brake separation between laminae during flexion of spine
segmental syndesmosis
Interspinous ligaments anteriorly meet:
and posteriorly meet:
anteriorly: ligamentum flava
posteriorly: supraspinous ligament
segmental syndesmosis
Interspinous ligaments location
Connect adjacent spinous processes along length
function of interspinous ligaments
limit flexion
segmental syndesmosis
Intertransverse ligaments location
between transverse processes of adjacent vertebrae
segmental syndesmosis
Intertransverse ligaments in cervical:
largely replaced by intertransverse muscles
segmental syndesmosis
Intertransverse ligaments in thoracic:
blend with adjacent muscles
segmental syndesmosis
Intertransverse ligaments in lumbar:
thin and membranous
function of intertransverse ligaments
limit lateral flexion
segmental syndesmosis
Alar ligaments location
Arise from each side of apex of dens, ascend laterally to impressions on medial sides of occipital condyles
segmental syndesmosis
Alar ligaments function
Relax in extension
Tighten in flexion
Check rotation to contralateral side
Lateral atlantoaxial joints location
Between lateral masses of atlas and superior facets of transverse processes of axis
lateral atlantoaxial joint classification
plane, synovial
segmental syndesmosis
Describe accessory ligament
posteromedial thickening at lateral atlantoaxial joints (Zygoapophyseal joints of C1-C2)
segmental syndesmosis
Cruciate ligament is formed by:
transverse atlantal ligament, superior and inferior longitudinal ligaments
Transverse Atlantal ligament attachments
Wraps around dens of C2, between lateral masses of C1
cruciate ligament
Superior band of
longitudinal fibers location
arise from transverse ligament and attaches to clivus deep to tectorial membrane
cruciate ligament
Inferior band of longitudinal fibers location
arises from transverse ligament, attaches to body of axis deep to PLL
atlantoaxial joints
Vertebrae are connected via:
posterior and anterior atlantoaxial membranes
segmental syndesmosis
Tectorial membrane is a continuation of:
Posterior Longitudinal Ligament (PLL)
segmental syndesmosis
Tectorial membrane location
Ascends posterior to dens and cruciate ligament
Attaches to clivus of occipital and sphenoid
(Body C2-clivus)
segmental syndesmosis
Tectorial membrane blends with:
cranial dura mater
segmental syndesmosis
Apical dental ligament location
attaches dens of axis to occipital bone
Intervertebral discs are thicker in ____ and ____ regions, allowing for…
Lumber & cervical
Greater mobility
Functions of intervertebral discs
- bear weight
- dissipate shock (higher water content)
- distribute load
- flexible buffer between rigid vertebrae
- adequate motion at low loads, stability at higher loads
What type of joint are intervertebral discs?
Symphysis
Kyphosis
Convex posteriorly
Lordosis
Convex anteriorly
Scoliosis
Lateral curvature (pathological)
Severe untreated scoliosis can cause…
Deformity of rib cage and vertebral curvature
Structural vs functional scoliosis
Structural:
- hemivertebra
- age ~10-15 years
Functional:
- muscles tight on one side
- uneven hips - spine curves to compensate
