Term
| functions of the vertebral column |
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Definition
1. protects the spinal cord
2. supports the weight of the body superior to the level of the pelvis
3. provides a partially rigid and flexible axis for the body and an extended base on which the head is placed and pivots
4. plays an important role in posture and locomotion |
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Term
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Definition
| the movement from one place to another |
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Term
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Definition
| articulated bones of the cranium, vertebral column, ribs, and sternum |
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Term
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Definition
cervical (7)
thoracic (12)
lumbar (5)
sacral (5) - fused in adults to form the sacrum
coccyx (4) - fuse after age 30 to form the coccyx |
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Term
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Definition
| occurs at the junction of, and is formed by, the long axes of the lumbar region of the vertebral column and the sacrum |
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Term
| synovial zygapophysial joints |
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Definition
- locations at which the 25 superior vertebrae articulate
- facilitate and control the vertebral column's flexibility |
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Term
| a typical vertebral body consists of: |
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Definition
1. a vertebral body
2. a vertebral arch
3. seven processes |
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Term
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Definition
- more massive, roughly cylindrical, anterior part of the bone
- gives strength to the vertebral column and supports body weight
- size increases as column descends (most markedly from T4 inferiorly)
- consists of vascular, trabecular (spongy cancellous) enclosed by a thin external layer of compact bone
- one or more large foramina in the posterior surface accommodate basivertebral veins that drain the marrow |
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Term
| trebecular bone of the vertebral body |
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Definition
- meshwork of mostly tall trabeculae intersecting with short, horizontal trabeculae
- intersects occupied by red marrow that is among the most active hematopoietic tissues of a mature individual |
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Term
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Definition
- ring of smooth bone, derived from an anular epiphysis, fused to the body
- serve as growth zones
- provide protection to the vertebral bodies and permit some diffusion of fluid between the IV disc and the capillaries in the vertebral body |
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Term
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Definition
- location where the superior and inferior epiphyses unite
- primary ossification center for the central mass of the vertebral body early in adult life |
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Term
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Definition
| - posterior to the vertebral body and consists of 2 pedicles and laminae |
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Term
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Definition
| - short, stout, cylindrical processes that project posteriorly from the vertebral body to meet the laminae |
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Term
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Definition
| broad, flat, plate of bone, which unite in the midline |
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Term
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Definition
| formed by the vertebral arch and the posterior surface of the vertebral body |
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Term
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Definition
- formed by the succession of vertebral foramina in the articulated vertebral column
- contains the spinal cord and the roots of the spinal nerves that emerge from it, along with the membranes (meninges), fat, adn vessels that surround and serve them |
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Term
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Definition
| indentations observed in lateral views of the vertebrae superior and inferior to each pedicle between the superior and inferior articular processes posteriorly and the corresponding projections of the body anteriorly |
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Term
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Definition
- formed by the superior and inferior vertebral notches of adjacent vertebrae and the IV discs connecting them
- spinal (posterior root) ganglia are located here
- spinal nerves emerge here with their accompanying vessels |
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Term
| processes of the vertebral arch |
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Definition
- 1 median spinous process
- 2 transverse processes
- 4 articular processes |
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Term
| spinous process of vertebral arch |
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Definition
- projects posteriorly (and usually inferiorly, typically overlapping the vertebrae below) from the vertebral arch at the junction of the laminae
- afford attachment for deep back muscles and serve as levers, facilitating the muscles that fix or change position of the vertebrae |
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Term
| transverse processes of vertebral arch |
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Definition
- project posterolaterally from the junctions of the pedicles and laminae
- afford attachment for deep back muscles and serve as levers, facilitating the muscles that fix or change position of the vertebrae |
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Term
| articular process of vertebral arch |
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Definition
- two superior and two inferior
- also arise from the junctions of the pedicles and laminae
- each bear an articular surface (facet)
- in apposition with corresponding processes of vertebrae adjacent to them, forming zygapophysial (facet) joints
- determine the types of movement permitted and restricted between adjacent vertebrae of each region
- assist in keeping adjacent vertebrae aligned, particularly preventing one vertebrae from slipping anteriorly on the vertebrae below
- generally bear weight only temporarily
- inferior articular processes of L5 bear weight even in erect posture |
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Term
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Definition
- the surgical excision of one or more spinous processes and adjacent supporting vertebral laminae in a particular region of the vertebral column
- performed surgically to gain access to the vertebral canal, providing posterior exposure of the spinal cord (if performed above L2) and roots of specific nerves
- often performed to relieve pressure on the spinal cord or nerve roots caused by tumor, herniated IV disc, or bony hypertrophy |
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Term
| cervical vertebrae characteristics |
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Definition
- form the skeleton of the neck
- smallest of the 24 moveable vertebrae
- located between the cranium and the thoracic vertebrae
- bear less weight than those of inferior regions
- cervical IV discs thinner then those inferior but relatively thick compared to the size of vertebral bodies they connect
- greatest range and variety of movement
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Term
| transverse foramen of cervical vertebrae |
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Definition
- single most distinctive feature
- in the transverse process
- vertebral arteries and their accompanying veins pass though (except C7: transmits only small accessory veins; foramina in C7 smaller and occasionally absent) |
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Term
| anterior and posterior tubercle of cervical vertebrae |
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Definition
- transverse processes end laterally in these two projections
- provide attachment for a laterally placed group of cervical muscles (levator scapulae & scalenus)
- grooves on the transverse processed between tubercles (floor of groove being formed by costotransverse bar) accommodate the anterior rami of the cervical spinal nerves |
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Term
| carotid tubercles of vertebra C6 |
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Definition
| - named because common carotid arteries may be compressed here, in the groove between the tubercle and body, to control bleeding from these vessels |
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Term
| vertebrae C3-C7 characteristics |
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Definition
- demonstrate all features typical of cervical vertebrae: have large vertebral foramina to accommodate the enlargement of the spinal cord in this region in relation to the innervation of the upper limbs
- superior borders of transversely elongated bodies are elevated posteriorly and especially laterally btu are depressed anteriorly, resembling somewhat a sculpted seat
- inferior border of the body of the superiorly placed vertebra is reciprocally shaped
- adjacent cervical vertebrae articulate in a way that permits free flexion and extension and some lateral flexion but restricted rotation
- planar, nearly horizontal articular facets of the articular processes also favorable for these movements |
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Term
| uncus of the body (uncinate process) of cervical vertebrae |
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Definition
| elevated superolateral margin |
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Term
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Definition
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Term
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Definition
- C1
- has neither a body, nor a spinous process
- ring shaped
- has paired lateral masses that serve the place of a body by bearing the weight of the cramium
- transverse processes arise from the lateral masses, causing them to be more laterally placed then those inferior
- widest of the cervical vertebrae, providing increased leverage for attached muscles |
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Term
| superior articular surfaces of the lateral masses of the atlas |
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Definition
- kidney shaped & concave
- receive two large protuberances- occipital condyles, at the sides of the foramen magnum |
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Term
| anterior & posterior arches of the atlas |
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Definition
- each bears a tubercle in the center of its external aspect, extended between the lateral masses, forming a complete ring
- posterior arch, corresponds to lamina of a typical vertebra, has a wide groove for the vertebral artery on its superior surface (C1 also runs in this groove) |
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Term
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Definition
- C2
- strongest of the cervical vertebrae
- the ATLAS rotates ON the AXIS ("no" movement of the head) via two large, flat bearing surfaces - the superior articular facets
- large bifid spinous process that can be felt deep in the nuchal groove, the superficial vertical groove at the back of the neck |
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Term
| dens (odontoid process) of the axis |
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Definition
- distinguishing factor
- blunt tooth-like
- projects superiorly from the body of the axis
- the dens and spinal cord inside its covering are encircled by the atlas
- lies anterior to the spinal cord and serves as a pivot about which the rotation occurs |
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Term
| transverse ligament of the atlas |
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Definition
- holds the dens in position against the posterior aspect of the anterior arch of the atlas
- extends from one lateral mass of the atlas to the other, passing between the dens and spinal cord, forming the posterior wall of the "socket" that receives the dens
- prevents posterior (horizontal) displacement of the dens and anterior displacement of the atlas |
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Term
| dislocation of cervical vertebrae |
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Definition
- Cvert less tightly locked than other vert, stacked like books, & can be dislocated in neck injuries with less force than is required to fracture them.
- b/c large vertical canal in cervical region, slight dislocation can occur w/o damaging the spinal cord
- severe dislocations, or dislocations combined with fractures (fracture-dislocations) imjure the spinal cord
- if disloc. doesn't result in "facet jumping" with locking of the displaced articular processed, the Cvert may self-reduce so that a radiograph may not indicate that the cord has been injured (MRI may reveal soft tissue damage) |
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Term
| fracture & dislocation of the Atlas |
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Definition
- b/c the thick side of the lateral mass wedges is directed laterally, vertical forces (as would result to a blow to the head from a falling object, or striking the bottom of a pool in a diving accident) compressing the lateral masses btwn the occipital condyles and the axis drive them apart, fracturing one or both of the bony arches.
- if force sufficient, rupture of transverse ligament will occur
- resulting Jefferson or burst fracture, in itself doesn't necessarily result in spinal cord injury b/c dimensions of bony ring actually increase
- spinal cord injury more likely if transverse ligament has also been ruptured, indicated radiographically by widely spread lateral masses |
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Term
| fracture & dislocation of the Axis |
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Definition
- fractures of vertebral arch of the axis are one of the most common injuries of the Cvert (up to 40%)
- usually occurs in bony column formed by the superior and inferior articular processes of the axis, the pars interarticularis; fx here, called a traumatic spondylolysis of C2 usually occurs as a resuly of hyperextension of the head on the neck, rather than combined hyperextension of the head and the neck, which results in a whiplash injury
- hyperextention of the head used in hanging criminals, thus this fx is commonly called a hangman's fx
- more severe injuries, body of C2 is displaced anteriorly with respect to body of C3; w/ or w/o such subluxation (incomplete dislocation) of axis, injury of spinal cord and/or brainstem is likely, sometimes resulting in quadriplegia or death
- fracture of the dens also common in axis injuries (40-50%) which may result from horizontal blow to the head or as a complication of osteopenia (pathological loss of bone mass) |
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Term
| thoracic vertebrae characteristics (focus T5-T8) |
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Definition
- lie in the upper back and provide attachment for the ribs
- primary feature = costal facets for articulation with the ribs
- middle 4 (T5-T8) demonstrate all features typical of a Tvert: articular processes extend vertically with paired, nearly coronally oriented articular facets that define an arc centered in the IV disc which permits rotation (greatest degree) and some lateral flexion of the vertebral column in this region
- attachment of rib cage combined with vertical orientation of articular facets and overlapping spinous processes limits flexion and extension as well as lateral flexion |
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Term
| thoracic vertebrae characteristics (focus T1-T4) |
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Definition
- share some features of cervical vertebrae
- T1 atypical in that has a long, almost horizontla spinous process that may be nearly as prominent as that of the vertebra prominens
- T1 also has a complete costal facet on the superior edge of its body for the 1st rib and a demifacet on its inferior edge that contributed to the articular surface for the 2nd rib |
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Term
| thoracic vertebrae characteristics (focus T9-T12) |
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Definition
- have some features of lumbar vertebrae, including tubercles similar to the accessory and mamillary processes of lumbar vertebrae
- most transition in characteristics from thoracic to lumbar occurs over T12
- superior half of T12 thoracic in character, having costal facets and articular processes that permit only flexion and extension
- T12 subject to transitional stress that cause it to be the most commonly fractured vertebra |
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Term
| lumbar vertebrae characteristics |
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Definition
- located in the lower back between the thorax and sacrum
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