7 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral (fused to form sacrum), 4 Coccygeal (fused to form coccyx)=33
Number of spinal nerves
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal=31
Curves of spine
Concave posteriorly=cervical,lumbar=secondary curvatures b/c form when infant learns to hold its head ~3-4 months-lordotic
Concave anteriorly=thoracic,sacral=primary curvatures b/c develop in fetal life and present at birth-kyphosis
What is the primary curvature of cervical spine called?
Abnormal curvatures of the spine
kyphosis=exaggerated posterior curvature of the spine (hunchback)
lordosis=exaggerated anterior curvature of the spine (sway/saddleback)
scoliosis=lateral curvature of the spine)
Components of typical vertebrae
vertebral body, vertebral arch (lamina and pedicle), vertebral foramen, spinous process, transverse process (2), articular process (4)
Processes and Facets
(1) median Spinous process
Transverse process (2) with a transverse costal facet
(2)Superior/(2)Inferior articular process with facet
Superior/Inferior costal facet (come off posterior to body)
wider body, triangular verteb foramen, transverse foramen (for vertebral arteries)
C3-C5 short and bifid SP while C7 long
C1 (atlas) no spinous process or body
C2 (axis) strongest cervical, dens
heart shaped body, bears 1 or 2 costal facets
circular and smaller vertebral foramen than C & L
long SP slopes posteroinferiorly
massive kidney shaped body
triangular vertebral foramen larger than T, smaller than C
SP short and sturdy, hatchet shaped
Fx=formed by fusion of 4 or 5 vertebrae and transmits body weight to the bony pelvis via the sacro-iliac joints
-facets of superior articular processes
-lateral,intermediate, medial sacral crests
-posterior/ant sacral foramina (4 pairs)=SACRAL SPINAL NERVES PASS THROUGH
IV=intervertebral discs=secondarily cartilaginous joints (symphyses-weight bearing & strength) and fibrocartilagenous
Zygapophyseal=plane-type of synovial, sup/inf articular facets (joints of the vertebral arches, facet joint)
Craniovertebral=atlanto-occipital and atlanto-axial
IV disc components
Nucleus pulposus (internal matrix) surrounded by Anulus fibrosus (external covering of IV disc)
Level most superior IV disc found=C2-C3
Level most inferior IV disk found=L5-S1
where lateral part of body, meets adjacent superior vertebra?????
-homologous to supraspinous and interspinous ligaments in the cervical region
-it is a midsagittal membrane that separates the muscles on the 2 sides of the posterior neck and provides attachment for the muscles
-it attaches to the atlas and remaining cervical SP
-role is to help support the wt of head when flexion.
-bicondylar synovial joints
-established b/t occipital condyles and superior articular facets on lateral masses of atlas
-each joint has its own articular capsule
-allows for flexion/extension and some lateral flexion (but practically no rotation) "yes"
-occipital bone and atlas are connected by the anterior and posterior atlanto-occipital membranes/ligament
each joint is surrounded by a thin, loose capsule which is attached to the margins of the articular surfaces of the articular processes of adjacent vertebrae
-found b/t bone, atlas, axis
-specifically adapted for movements of the head
-remember, no IV discs at this point & all joints are classified as synovial
-2 atlanto-occipital membranes (ant and post)
3 atlanto-axial (2 lateral-lateral masses of C1 and superior facets of C2, 1 median-b/t dens of C2 and anterior arch and transverse ligament of C1)
(1 median-dens a pivot joint and 2 facet)..."no" movt.
State joint b/t the skull and C1?
State the areas of articulation between the skull and C1
The occipital condyles of the skull and the superior articular facets of the atlas
Give the ligament that attaches C1 to the skull
the anterior and posterior atlanto-occipital membranes
State the motion that occurs at the atlanto-occipital joint
Flexion and extension or nodding
Lateral atlanto-axial joints
established between the inferior articular facets on the lateral masses of atlas and superior articular facets of axis
Median atlanto-axial joint
pivot joint established b/t dens of axis and osteo-fibrous ring formed by the anterior arch of atlas and transverse ligament of atlas
Transverse ligament of atlas
extends b/t the 2 lateral masses of the atlas-->retains(holds) the dens in position thus preventing impingement of spinal cord
Movt of atlanto-axial joint
Rotation ("no"). Atlas rotates on axis and carries head with it
portion of C2 that projects superiorly & articulates with the anterior arch of C1
4 major ligaments found at the atlanto-occipital joint?
-alar ligament, superior longitudinal, transverse, inferior longitudinal
Give the attachment of the transverse ligament
runs between tubercles on the lateral masses of C1 and supporting the Dens of C2
State purpose of transverse ligament
secures the dens with anterior arch of the C1
Cruciform ligament components
Superior longitudinal fibers
Inferior longitudinal fibers
Transverse ligament of atlas
extend from side of dens to the lateral margins of foramen magnum. Anterior to cruciform. prevent excessive rotation
Describe appearance of SP c2-c6 that make it unique
"bifid" and short
Which cervical verterbra are classified as "typical"
What are the characteristics of a typical cervical vertebrae
they have vertebral bodies, they articulate at the facets forming articular pillars, have joints of Luschka
Joints of Luschka
Uncovertebral....located between uncus of the bodies (uncinate processes) of the C3-C6 and superior
Unique about thoracic vertebrae?
costal facets (on transverse processes and on body, sup/inf)...where rib articulates with vertebrae
What structures make up vertebral arch?
Fused lamina posteriorly and the pedicles laterally
Number of processes which arise from the vertebral arch
Another name for the word facet? Name facets
Superior/Inf costal facets (demifacets), sup/inf articular facets, transverse costal facets
3 features of thoracic vertebra that distinguish them from C and L
-costal facets (demifacets) on their body
-costal facets on the transverse process
-long spinous process
Which vertebra have upper and lower demifacets to articulate withthe rib heads?
Why are the bodies of T5-T8 flatter on their left side?
due to the pressure of the descending aorta
More characteristics of thoracic vertebrae
-T1 has a vertebral foramen and body similar to a cervical vertebra
-T5-T9 vertebra have typical characteristic of thoracic vertebra
-T12 has a bony process and body simialr to a lumbar vertebra
At what level does the spinal cord terminate?
What is unique about the lumbar vertebra?
they have large bodies
What is the normal curvature of the lumbar spine?
Lordotic-considered a secondary curve because it develops after the fetal period
State the largest movable vertebra in the body
L5 and it also carries the largest amt of weight
What structure unique to the lumbar vertebras is located on the posterior surface of the superior articulating facet?
Mammillary processes. This is where the multifidus M attaches!!!!!!
More notes about lumbar
when on top of each other, can see inferior/sup vertebral notch, and Intervertebral foramen!
What is the function of the coccyx
acts as a site for muscle attachment (tail bone)
When does the fusion of the sacral vertebra begin?
After the 20th year of life
What part of the CNS can be found in the sacral canal?
cauda equina and filum terminale
What is the anterior projection edge of the S1 vertebra called?
Sacral promontory used to make measurements of the pelvic inlet
Anterior=strong and broad, covers and connects anterolateral aspects of vertebral bodies and IV discs. Extends from pelvic surface of sacrum to anterior tubercle of C1 and the occ bone . Maintains stability of IV joints and limits ext. of vertebra
posterior=narrower and weaker, runs within vertebral canal along posterior aspect of vertebral bodies. Attached mainly to IV discs and less to posterior edges of vertrbral bodies from C2
=pale yellow, elastic fibrous tissue that joins laminae of adjacent vertebral arches
-help preserve normal curvature and assist with straightening the column after flexing
-contributes to posterior boundaries of the intervertebral foramen and helps to strengthn the vertebral column after flexion
Interspinous and supraspinous ligaments
adjacent SP are united by weak, almost membranous IL and strong fibrous supraspinous (merges superiorly with the nuchal ligament
connecting adjacent transverse processes
What ligament plays an important role in stabilizing the vertebral podies
Ant/Post longitudinal ligaments
Where does the posterior longitudinal ligament run?
Along the posterior aspect of the vertebral bodies, within the vertebral canal
Most frequent direction of the nucleus pulposus herniation?
Posterior primarily due to hyperflexion
What lumbar IV disc herniation is most common?
Between L4 and L5 or between L5/S1
What happens to the turgor strength of the nucleus pulposus as people age?
Dehydration and degeneration cause this structure to lose its large water content (decreasing turgor) and facilitates herniation