wk 2 non contractile spine

What are the layers of vertebral column

Cervical C1-7

Thoracic T1-12

Lumbar L1-L5

Sacrum S1-5

Coccyx C1-4

What are the functions of the intervertebral discs

Protection

Supports weight

Movement

Muscle attachments

Primary Vertebral curvature

Kyphosis present in thoracic and sacral regions. They are curvatures initially present in utero

Secondary vertebral curvature

Lordosis. Present in cervical and lumbar regions which develops secondarily for lifting the head

Where is lordosis and kyphosis

Lordosis-lumbar spine

Kyphosis-thoracic

Pedicles and lamina

Pedicles form vertebral arch between transverse process and vertebral body

Lamina form arch beteeen articular processes and spinous process

Cervical vertebrae consists of

Typical vertebrae C3-6

Craniovertebrae C1 and C2

C7 vertebrae prominence

Thoracic vertebrae

12 vertebrae T1-12

Provides strong attachment for 12 pairs of ribs

Lumbar vertebrae

5 lumbar vertebrae L1-5

Sacral vertebrae

5 sacral vertebrae S1-5

Fused section of bone with no intervertebral disc

Provides rigid connection for ox cox to form pelvis

Coccygeal vertebrae

4 coccygeal segments

Fused called tailbone

What are the regional bony characteristics

Vertebral body

Vertebral arch-pedicles and lamina

Vertebral foramen- forms vertebral canal

Transverse process- one on each side

Spinous process- posterior

Articular processes and facets (zygapophyses)-superior and inferior

Cervical vertebrae characteristics

Body: small rectangular body with unicinate processes (part that sticks up laterally, preventing lateral translation of vertebrae). Only requires transferring the weight of the head

Vertebral foramen: large triangular due to all neurons descending past brain stem passing through cervical region

Transverse process:short with transverse foramen. Vascular passage with osseous protection for vertebral artery

Spinous process: BIFID shape. Allows for increased muscle attachment

What is unicinate processes

Part of vertebral body of cervical that sticks up laterally, preventing lateral translation of vertebrae

Thoracic vertebrae characteristics

Body:larger heart shape with costal facets (ribs attach posterior to vertebral body to make castrovertebral joints). Increase in weight transfer due to thoracic cavity

Vertebral foramen:smaller circular foramen

Transverse process:thick stout transverse processes with costal facets. Thoracic transverse processes need to be strong osseous processes due to articulation with ribs. Each transverse process has a single costal facets for castotranserse joint

Spinous process:inferiority directed. Projects inferiority so that tip or spinous process sits at the level up to 1 level below body

Lumbar vertebrae characteristics

Body:large kidney shaped. Supports, transfers and moves the weight of entire trunk

Vertebral foramen: larger triangle shape due to cauda equina

Transverse process:long and thin. Muscular attachments with laterality for torque

Spinous process:broad hatchet shaped. Large muscle attachment

Articular processes:have additional mammillary processes on the super articular process for attachment of multifidus and intertransversarii

Atypical vertebrae

C1-Atlas. No body and spinous process

C2-Axis

C7- vertebrae prominence

Articular processes orientation

Cervical: its superior articular facet is mostly in horizontal plane. Directed superiority and posteriorly. Sitting horizontally ontop of one another allowing for flexion extension and rotation

Thoracic: superior articular facet is in vertical plane. Directed posteriorly and slightly lateral. No limitation on rotation but in flexion and extension the top vertebrae will hit articular facets below

Lumbar:vertical plane. Directed medically and slightly posteriorly. Rotation is limited due to articular facets compressing together but in flexion and extension, there is no bony prominence preventing it

Intervertebral foramen

Superior aspect of foremen:inferior vertebral notch of level above

Inferior aspect:superior vertebral notch of level below

Anterior aspect: IV disc and IV body

Posterior aspect: ligamentum flavum and facet joint

What passes through intervertebral foramen

Spinal nerve root, dorsal root ganglion and spinal artery

Vertebral joints:

Atlanto-occipital joint C0-1 “yes”

Atlanto-axial joint C1-2 “no”

Uncovertebral joints C3-7

Facets or zygapophysial joints

Intervertebral joints

Atlanto-occipital joint C0-1

Occipital (back part of skull) codyles articulate with superior articular facet of atlas

Forms synovial Condyloid joint

Allows 25 deg of flexion and extension of head- yes joint

Atlanto-axial C1-2 no joint

Forms 3 distinct joints:

2 lateral zygapophyseal joints between articular facet

1 medial joint as dens articulates with anterior arch of atlas

Synovial pivot joint

Allows for rotation of head 50-80 deg- no joint

Uncovertebral joints C3-7

Prevents lateral flexion and lateral translation of cervical vertebrae

Facets of zygopophyseal joints

Inferior articular process of superior vervetrae meets superior articular process of the inferior vertebrae

Synovial plane joint

Intervertebral joint

Vertebral bodies articulate at cartilaginous joints

Made up of nucleus pulposus, the inner portion of disc and outer annulus fibrosis

Nucleus pulposus:

higher water content

Inner portion of disc

Annulus fibrosis:

Outer portion of disc

Comprised of highly compact collagen fibrils which binds one end plate to another

Opposing oblique fibres that bind 1 vertebrae to another to allow rotation restriction

What makes up intervertebral joint

IV disk

Nucleus pulposus and annulus fibrosis

Function of intervertebral discs

1.binds vertebrae together- annulus fibrosis binds

2.absords load- nucleus polposus squishing

3.limits movement-concentric lamellae preventing excessive movement

Ligaments of vertebral column

Transverse ligament of atlas

Nuchal ligament

Supraspinous ligament

Interspinous ligament

Anterior longitudinal ligament

Posterior longitudinal ligament

Ligamentum flavum

Transverse ligament of atlas

Attaches: Atlas (C1) medial to atlanto-occipital joint bilaterally

Limits C1 moving anteriorly on C2

Nuchal ligament

Attaches: external occipital protuberance to cervical spinous process (C7)

Limits head falling forwards

Thick firboelastic tissue, continuous with supraspinous ligament

Supraspinous ligament

Attaches from C7 tip of spinous process to sacrum

Limits flexion of head

Interspinous ligament

Attaches from superior spinous process to inferior spinous process

Limits anterior translation and flexion of head

Anterior longitudinal ligament

Attaches from anterior C1 vertebra and occipital bone to anterior sacrum

Limits extension

Posterior longitudinal ligament

Attaches from C2 discs and vertebral bodies inside canal to posterior sacrum

Limits flexion

Ligamentum flavum

Attaches from lamina of superior vertebrae to lamina of inferior vertebrae

Limits flexion

Not continuous. Thick yellow elastic tissue