Vertebral Column Flashcards
How many vertebrae are there?
33 - 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused sacrum), 4 coccygeal (coccyx)
What does it mean to have primary curvature and what two regions do?
Same curvature as embryonic development, concave ventrally (anteriorly). The thoracic and sacral regions have this. Lumbar and cervical regions are the opposite (secondary curvature)
What is the vertebral body vs the vertebral arch?
Body - provides support and weight-loads of the body (discs are between)
Arch - rest of vertebrae, surrounds spinal cord and has muscle attachments
What are the pedicles and lamina of a vertebrae?
Pedicle - between vertebral body and transverse process
Lamina - between transverse and spinous processes.
They make up the vertebral arch and come in pairs. They also form the vertebral foramen
What do the alignment of all vertebral foramen of the cervical, thoracic, and lumbar vertebrae + sacral canal form?
vertebral / spinal canal
Where do the superior and inferior articular processes come from?
Superior - bony processes from the lamina above the transverse process
Inferior - bony processes from the lamina below the transverse process.
They form synovial joints. This is true for all spinal cord levels through the lumbar
What forms the intervertebral foramen?
The inferior vertebral notch at the pedicle level of the upper vertebrae, and the superior vertebral notch at the pedicle level of the lower vertebrae
What is the vertebrae prominens?
CV7, the largest spinous process. It is the only cervical vertebrae that can be palpated, and forms the first prominence felt at the back of your neck.
What is unique about all 7 cervical vertebrae?
They contain transverse cervical foramen next to their vertebral body, in the transverse processes. C1-C6 accommodate paired vertebral arteries. On C7, it accommodates the auxiliary vertebral vein.
What makes it possible for the neck to rotate about its axis (left or right), anterior flexion, posterior extension, and lateral flexion?
The relatively thick intervertebral discs between C2-C7.
What is the atlas? What does it lack?
Atlas = CV1. Lacks a vertebral body as well as a true spinous process (posterior tubercule instead). The transverse processes are connected by the anterior and posterior arches, which have the tubercules on them.
What allows for the nodding “yes” head motion?
The superior articular surface of the atlas (CV1) forms a synovial joint with the occipital condyle of the cranium, allows for anterior flexion and posterior extension.
What is the axis? What is its distinguishing feature?
CV2, has a prominent dens “tooth-like” process
What is the function of the dens?
It is on the top of CV2, attaches inferiorly to the anterior arch of the atlas. It is the pivot point for the “no” head movement”. Dens is anterior
What are the vertebral foramen and body like in thoracic vertebrae
“Heart-shaped” - vertebral body
Foramen - smaller than the cervical and lumbar regions
The spinous processes become shorter and more hatchet like down the spine
What are costal facets or demifacets?
They are articulation surfaces for synovial joints with ribs that will be on all thoracic vertebrae. The costal facets are on pedicle, demifacets are half-facets and form articulations with the neighboring vertebrae’s demifacet.
What is a transverse costal facet?
Only on TV1-TV10, they are articulations with the first 10 ribs via transverse processes, forming synovial joints.
How much movement does the thoracic level allow?
Anterior flexion and extension of the thorax, but less lateral rotation than the cervical region.
What shape characterizes lumbar vertebrae?
Kidney-shaped body. The superior and interior facets interlock to the lower levels, unlike cervical or thoracic vertebrae. Hatchet-shaped or quandrangular spinous processes.
What is the implication of the lumbar spinal cord level having interlocking articular facets?
You can still have flexion and extension but no LATERAL rotation.
What is the function of the fused sacral vertebrae?
Fuses during development, gives strength and stability to pelvis in pelvic girdle via sacroiliac joint. The bodies actually decrease in mass from SV1 to SV5.
What is the sacral canal?
Formed by the fusin of the vertebral canal from SV1-SV3, opens at SV4 level posteriorly at the sacral hiatus
What makes the sacral hiatus?
Incomplete closure of the lamina of SV4 and SV5. It is easily palpated by the presence of two lateral bony ridges called sacral horns at the SV5 level
How does SV1 interlock with LV5?
Superior articular facet interlocks with inferior articulating process of LV5.
What forms the sacroiliac joint?
The articular surfaces lateral on the posterior side of the sacrum.
What are the ala and promontory?
Promontory - name for the vertebral “body” of the sacrum at the top of SV1 which tapers
Ala - Wing-like structures of sacrum located laterally to the promontory
What makes up the intervertebral discs and how many are they?
23 discs, located inferiorly from CV2 to LV5. They have a central gelatinous portion (nucleus pulposus), and a ring of fibrous tissue (anulus fibrosus). Discs are ossified in sacral levels and absent in coccyx
How is an intervertebral disc held in position
Anulus fibrosus fuses with the annular epiphysis on either side of the vertebral bodies (superior and inferior)
What is the embryological remnant of a tail?
The 4 fused coccyx vertebrae