The Vertebral Column Flashcards
How many vetebrae are there in the body? What are the distributions?
33 vertebrae: 7 cervical 12 thoracic 5 lumbar 5 sacral (fused) 4 coccygeal (lower 3 are fused)
What are the seven processes that arise from the vertebral arch, and where do they project?
1 spinous process (projects posteriorly from two laminae)
2 Transverse processes (project laterally from junction of pedicle and laminae; where muscles and ligaments attaach)
4 Articular processes (project superiorly and inferiorly from vertebral arch; articulate with vertebrae above and below)
What makes up the vertebral arch?
The vertebral arch is the posterior part of the vertebra and are made of two laminae (complete the arch posteriorly) and two pedicles (form the side parts or walls of vertebral arch)
What encloses the vertebral foramen?
The body of the vertebra (the anterior weight bearing part) and the vertebral arch (posterior part)
What creates the intervertebral foramina? What goes through this foramen?
The notches in the pedicles of the upper and lower border form the intervertebral foramina. Allows passage of spinal nerves.
What are the movable vertebrae? How many are there?
Those vertebrae that are unfused (there are 24 of them: 7 cervical, 12 thoracic, and 5 lumbar)
What vertebral region allows for the greatest range and variety of movements?
Cervical vertebrae
What are the characteristic features of cervical vertebrae?
Bifid spinous process (splits at end, projects posteriorly)
large vertebral foramen (to give space for cervical enlargement of the cord)
Transverse process has a transverse foramen
The transverse foramen in the cervical vertebrae allows passage of what?
Vertebral arteries and veins
What are the characteristic features of the atlas?
Atlas (C1) lacks a body and spinous process
Possesses anterior and posterior arches
Has a lateral mass on each side with articular surfaces
What does the lateral mass of the atlas allow connection to, above and below?
The lateral mass allows for articulation with the occipital condyles of the skull (above) and articulation with the axis (below)
What is the characteristic feature of the axis?
Axis (C2) has the dens (or odontoid process) that projects from superior surface
What is the spinous process of the 7th cervical vertebrae called?
The vertebral prominens
What are the distinguishing features of the C7?
Vertebral prominens
Small transverse foramen (because it only transmits vertebral veins)
What are the distinguishing features of thoracic vertebrae? What do they articulate with?
Costal facets that articulate with ribs.
Costal facets on sides of bodies for articulation with heads of ribs
Costal facets on transverse processes for articulation with tubercles of ribs
What differs for T11 and T12 with regards to their costal facets?
No costal facets on transverse processes because ribs 11 and 12 tubercles don’t articulate there. Still have costal facets on bodies.
Describe the spinous processes of thoracic vertebrae
Vertebrae are long and inclined downward
Describe the vertebral foramen in the cervical, thoracic, and lumbar regions of the vertebral column.
The vertebral foramen is smallest in the thoracic segments and larger in the cervical and lumbar regions (to accommodate the cervical and lumbar enlargements)
Describe the body of thoracic vertebrae from T1 to T12
The bodies increase in size moving downward and are heart-shaped.
What are the defining features of the lumbar vertebrae?
Massive kidney shaped bodies
Thick, quadrangular spines that project posteriorly
Large vertebral foramina
What is the sacral promontory?
Bulging of the anterior and upper margin of the first sacral vertebra
What does the upper and lower border of the sacrum articulate with?
Upper border = Fifth lumbar vertebra
Lower border = coccyx (narrow inferior border)
Vertebral foramina in this segment form what?
The sacral canal
What is the sacral hiatus?
The failing to meet of the laminae of the 5th sacral vertebra at the midline. Nerve roots come out of the sacral hiatus
What passes through the foramina of the sacrum?
The upper four sacral nerves pass through the foramina.
Foramina are on the anterior and posterior surfaces to allow passage of the ventral and dorsal rami of the upper four sacral nerves.
Which sacral nerve comes out of the sacral hiatus?
The 5th sacral nerve
How many vertebrae make up the coccyx?
Four fused vertebrae (the fourth may or may not be fused)
What are the primary and secondary curvatures of the vertebral column?
Primary: Thoracic and Sacral
Secondary: Cervical and lumbar
What maintains the curvature of the thoracic and sacral vertebrae?
Maintained primarily as a consequence of the differences in height between the anterior and posterior parts of the vertebrae
What maintains the curvature of the cervical and lumbar vertebrae?
Maintained primarily because of differences in the thickness of the anterior and posterior parts of the intervertebral discs
When does the cervical and lumbar curvature become prominent during development?
The cervical curvature is prominent when infant raises its head up. The lumbar curvature is prominent when infant begins to walk and is upright.
What is the name of exaggeration of the thoracic curvature?
Kyphosis
What is the name of exaggeration of the lumbar curvature?
Lordosis
What is scoliosis?
Lateral deviation of the vertebral column
What two components make up the intervertebral discs?
Annulus fibrosus and the nucleus pulposus
In which vertebral segments are the intervertebral discs thickest?
Thickest in the cervical and lumbar regions, where movement of the vertebral column is greatest.
What is the annulus fibrosis?
Consists of concentric layers of fibrocartilage which run obiquely from one vertebra to the next, and the fibers of one layer run at right angles to those of the adjacent layer
What is the nucleus pulposus?
Leftover embryonic cartilage, is an ovoid mass of gelatinous material which contains a large amount of water, small amount of collagen, and some cartilage cells. Situated near the posterior part of the disc
Which vertebrae do not have intervertebral discs running between them?
Between C1 and C2.
Where is the most inferior intervertebral disc?
Between L5 and the sacrum (S1)
Which ligament runs along the front of the vertebral column? What type of extension does it resist?
The anterior logitudinal ligament, resists hyperextension (is the only ligament to resist hyperextension). Strong wide band
What ligament runs along the back of the vertebral column? What type of extension does it resist?
The posterior longitudinal ligament, resists hyperflexion. Weaker and more narrow than the anterior logitudinal ligament. Resists posterior herniation of the intervertebral discs
What ligament runs between lamina? What is its function, and what type of extension does it resist?
The ligamentum flava in the vertebral column is made of yellow elastic tissue; resists flexion (or bending forward), assists in the straightening of the column after flexion
What is the ligamentum nuchae? Where does it extend to and from?
Is white fibrous ligament (not elastic) and is the thickening of the interspinous and supraspinous ligaments in the cervical region. Extends from C7 to the external occipital protuberance. Provides attachment of muscles on either side of the neck
What are the two craniovertebral joints?
Atlanto-occipital joint and the atlanto-axial joint
Where is the atlanto-occipital joint and what movement of the head does it allow?
Is a joint between the superior articular surface o hte lateral mass of the atlas and the occipital condyles of the skull; allows for the “yes” movement of the head (so the skull moves alone)
What is the atlanto-axial joint, what joints make it up, and what movement of the head does it allow?
Consists of three joints: 1 median joint (between the dens of the axis and the anterior arch of the atlas) and 2 lateral joints (between the lateral masses of the atlas and the superior facets of the axis); allows the “no” movement of the head (so skull and axis move together)
