Chapter 8 Vertebral Column Anatomy
4 functions of the vertebral column:
- encloses and protects the spinal cord - acts as a support for the trunk - supports the skull superiorly - provides for attachment for the deep muscles of the back and ribs laterally
How much of the length of the vertebral column does the intervertebral disks make up
1/4
The zygapophyseal joints of the thoracic region, except the inferior articular processes of the twelfth vertebrae, angle anteriorly approximately _________________________ degrees to form an angle of ________________________ degrees (open anteriorly) to midsagittal plane of body
15-20 70-75
2 parts of the vertebral arch:
2 pedicles 2 laminae
Arise from the junction of the pedicles and laminae to articulate with the vertebrae above and below
2 superior and 2 inferior articular processes
How many vertebral segments in the upper three regions of the vertebral column?
24
______________% of L1-2 and L2-3 zygapophyseal joints are shown on an AP projection, and a small percentage of L4-5 and L5-S1 joints are seen on a lateral projection
25%
How many foramina do the cervical vertebrae contain?
3
The zygapophyseal joints of the lumbar region are inclined posteriorly from the coronal plane, forming an average angle (open posteriorly) of __________________________ degrees to the midsagittal plane of body
30-60
How many total bones make up the vertebral column?
33
How many curves does the vertebral column have?
4
The intervertebral foramina of the cervical region are directed at a ______________________ angle from the midsagittal plane of the body and at inferior angle of ______________________ to the horizontal plane of the body; so what CR and pt angulation is need for proper demonstration of these froamina
45-degree 15 degrees 15-degree longitudinal angulation of CR 45-degree medial rotation of the pt
The spinous process of the ___________________________ lumbar vertebra is smaller and shorter, and the transverse processes are much thicker than those of the upper lumbar vertebrae
5th
The body of which segment of the lumbar vertebrae is considerably deeper in front than behind, giving it a wedge shape that adapts it for articulation with the sacrum
5th segment
Numerous upper zygapophyseal joints have no angle, and many lower ones have an angle of _______________ degrees or more
60
How many cervical, thoracic, lumbar, sacral, coccygeal vertebrae are there?
7 Cervical, 12 Thoracic, 5 lumbar, 5 sacral, 3-5 coccygeal
To show the zygapophyseal joints of the thoracic region, the pt's body must be rotated _________________________ degrees from the anatomic position or _________________________ degrees from the lateral position
70-75 15-20
The joints created by the joining of the superior articular processes of the axis and the inferior articular processes of the atlas are clearly visualized in what projection if pt is properly positioned
AP projection
Kyphosis
Abnormally increased anterior concavity (posterior convexity) in the thoracic curvature
Lordosis
Abnormally increased anterior convexity (posterior convexity) of the cervical and lumbar spine
Clay shoveler's fracture
Avulsion fracture of the spinous process in the lower cervical and upper thoracic region
Why is spondylolisthesis of radiographic importance?
Because oblique-position radiographs show the "neck" area of the "Scottie dog"
Spondylolysis
Breaking down of the vertebra
The spinous process of this vertebra is easily palpable at the posterior base of the neck and is a guide in localizing other vertebrae
C7
Jefferson fracture
Comminuted fracture of the ring of C1
Spina bifida
Failure of the posterior encasement of the spinal cord to close
Spondylolisthesis
Forward displacement of a vertebra over a lower vertebra, usually L5-S1
Hangman's fracture
Fracture of the anterior arch of C2 owing to hyperextension
Compression fracture
Fracture that causes compaction of bone and a decrease in length or width
Scheuermann disease or adolescent kyphosis
Kyphosis with onset in adolescence
Scoliosis
Lateral deviation of the spine with possible vertebral rotation
Herniated nucleus pulposus
Rupture or prolapse of the nucleus pulposus into the spinal canal
The cervical and lumbar curves are called ________________________ because they develop after birth
Secondary curves
What is the purpose of the vertebral column developing a second or compensatory curve in the opposite direction with scoliosis?
To keep the head centered over the feet
Forms the central axis of the skeleton and is centered in the midsagittal plane of the posterior part of the trunk
Vertebral Column
When does the cervical curve develop?
When an infant begins to hold the head up at about 3-4 months of age and begins to sit up alone at about 8-9 months of age
When does the lumbar curve develop?
When the child begins to walk at about 1 - 1 1/2 years of age
At the back of the root of the transverse process of the lumbar vertebrae
accessory process
Large, winglike lateral masses on each side of the sacral base
ala
Outer fibrocartilaginous disk that surrounds the nucleus pulposus of the intervertebral disks
annulus fibrosus
These parts of the atlas extend between the lateral masses
anterior and posterior arches
Parts of the atlas:
anterior arch posterior arch 2 lateral masses 2 transverse processes
What is the result of small transversely located, oblong body with slightly elongated anteroinferior borders?
anteroposterior overlapping of the bodies in the articulated column
The inferior surface of the _______________________ of the sacrum has an oval facet for articulation with the coccyx and sacral cornua
apex
This part of the sacrum is directed posteriorly and inferiorly
apex
The superior and inferior surfaces of the bodies of the vertebra are flattened and are covered by a thin plate of ________________________________
articular cartilage
Together the superior and inferior articular processes of the typical cervical vertebra form short, thick columns of bone called _____________________________________
articular pillars
A large articular process at the superoanterior part of the lateral surface of each ala for articulation with similarly shaped processes on the iliac bones of the pelvis
articular surface
Articulation formed by the anterior arch of the atlas rotating around the dens of the axis Type: Movement:
atlantoaxial joint 2 lateral synovial gliding, 1 medial synovial pivot (dens) both freely movable
Articulations between the atlas and the occipital bone Type: Movement:
atlantooccipital joints synovial ellipsoidal freely movable
The first cervical vertebra (C1), a ringlike structure with no body and a very short spinous process
atlas
Second cervical vertebra (C2), has a strong conical process arising from the upper surface of its body
axis
This part of the sacrum is broad and directed obliquely, superiorly, and anteriorly
base
Does the palpable tip of each spinous process of the fifth to ninth thoracic vertebrae correspond in position to the interspace above or below the vertebra from which it projects?
below
Anterior mass of the vertebra, approximately cylindric in shape and is composed largely of cancellous bony tissue covered by a layer of compact tissue, has flattened posterior surface from superior aspect and concave anterior and lateral surfaces from lateral aspect
body
2 main parts of the vertebra:
body vertebral arch
The body of the vertebra is composed largely of _________________________________
cancellous bony tissue covered by a layer of compact tissue
The average angle of the zygapophyseal joints increase from __________________________ to _______________________ L1-2 at ____________________ degrees L2-3 at ___________________ degrees L3-4 through L5-S1 at ___________________ degrees
cephalad to caudad 15 30 45
Superior thoracic bodies resemble bodies of which vertebrae?
cervical
The least pronounced of the curves of the vertebral column
cervical curve
The seven superiormost vertebrae that occupy the region of the neck
cervical vertebrae
5 groups of the vertebral column:
cervical vertebrae thoracic vertebrae lumbar vertebrae sacral vertebrae coccygeal vertebrae
4 curves of the vertebral column:
cervical, thoracic, lumbar, and pelvic
Projects superiorly from the posterolateral aspect of the first coccygeal segment to join the sacral cornua
coccygeal cornua
Terminal vertebrae, also in pelvic region, vary from three to five in number in adults
coccygeal vertebrae
Composed of three to five (usually four) rudimentary vertebrae that have a tendency to fuse into one bone in the adult; it diminishes in size from its base inferiorly to its apex, from its articulation with the sacrum, it curves inferiorly and anteriorly, often deviating from the midline of the body
coccyx
When viewed posteriorly, the normal lumbar curve can correctly be referred to as ____________________________________
concave posteriorly
The vertebral curves are discussed in reference to the anatomic position and are referred to as ___________________________________ or ____________________________________
convex anteriorly concave anteriorly
The posterolateral margins of each thoracic body have _____________________________________ for articulation with the heads of the ribs
costal facets
Articulations between tubercles of the ribs and the transverse processes of the thoracic vertebrae Type: Movement:
costotransverse joints synovial gliding freely movable
Articulations between the heads of the ribs and the bodies of the vertebrae in the thoracic region Type: Movement:
costovertebral joints synovial gliding freely movable
The __________________________ of the vertebral column arch anteriorly and posteriorly from the midcoronal plane of the body
curves
Which body position shows most clinically significant lumbar zygapophyseal joints (L3-S1)
customary 45-degrees oblique position
What kind of facets do the bodies of the second through eighth thoracic vertebrae contain superiorly and inferiorly?
demifacets
Strong conical process arising from the upper surface of its body, is received into the anterior portion of the atlantal ring to act as a pivot or body for the atlas
dens (odontoid process)
The anterior portion of the ring of the atlas receives the ____________________ of the axis, an the posterior portion transmits the proximal spinal cord
dens (odontoid process)
Are interposed between the vertebrae and act as cushions
disks of fibrocartilage (intervertebral disks)
Except for the eleventh and twelfth pairs, each process of the thoracic vertebrae has on the anterior surface of its extremity a small concave ____________________ for articulation with the tubercle of the rib
facet
The articulating surfaces of the four articular processes that are covered with fibrocartilage
facets
The pelvic segments in the two lower regions are called ______________________________________
false or fix vertebrae
The sacrum is more acutely curved, with its greatest curvature in the lower half of the bone; it also lies in a more oblique plane, which results in a sharper angle junction of the lumbar and pelvic curves. Is this a male or female?
female
Are the lumbar and pelvic curves more pronounced in males or females? Why?
females they have a more acute angle at the lumbosacral junction
Bodies of the thoracic vertebrae increase in size from the __________________ to ___________________ vertebrae
first-twelfth
4 movements permitted in the vertebral column by the combined action of the joint are:
flexion extension lateral flexion rotation
Rupture or protrusion of the nucleus pulposus of the iintervertebral disks into the vertebral canal, impinging on a spinal nerve
herniated nucleus pulposus (HNP) or herniated disk
What causes HNP of the lumbar region? What can this cause?
improper body mechanics or poor posture considerable discomfort and pain
From the second cervical vertebra to the superior part of the sacrum the width of the spine gradually _____________________ and then it ______________________ sharply
increases decreases
Each lateral mass of the atlas bears a ________________________________ and a _________________________________
inferior and superior articular process
Each _________________________________________ has an articular facet on its anterior surface
inferior articular process
Separate the vertebral bodies forming a cartilaginous intervertebral joints
intervertebral disks
By the articulation with the vertebrae above and below, the notches form _______________________________________ for the transmission of spinal nerves and blood vessels
intervertebral foramina
The ________________________________ of the lumbar region are situated at right angles to the midsagittal plane of the body, except for the fifth, which turns slightly anteriorly
intervertebral foramina
The _________________________________________ of the thoracic region are perpendicular to the midsagittal plane of the body; they are clearly shown with the pt in what position?
intervertebral foramina lateral
Articulations between the two vertebral bodies Type: Movement:
intervertebral joints cartilaginous symphysis slight movable
Any abnormal increase in the anterior concavity (or posterior convexity) of the thoracic curve
kyphosis
The thoracic and pelvic curves are concave anteriorly and are called ________________________________
kyphotic curves (primary curves)
Broad, flat, and directed posteriorly and medially from the pedicles
laminae
The _____________________________ of the axis are broad and thick
laminae
The __________________________________ of the typical cervical vertebra are narrow and thin
laminae
The ________________________ of the thoracic vertebrae are broad and thick, and they overlap the subjacent lamina and the __________________________ are long
laminae spinous processes
The concavities on the upper surface of the pedicles of the first sacral segment and the corresponding concavities on the lower surface of the pedicles of the last lumbar segment form the _________________________________________
last pair of intervertebral foramina
The zygapophyseal facet joints of the second through seventh cervical vertebrae are clearly shown in what projection
lateral
What projection is necessary to show the cervical zygapophyseal joints
lateral
The vertebral column is held together by ___________________________ Why is it jointed and curved?
ligaments so that is has considerable, flexibility and resilience
Any abnormal increase in the anterior convexity (or posterior concavity) of the lumbar or cervical curve
lordosis
The cervical and lumbar curves, which are convex anteriorly, are called ___________________________
lordotic curves (secondary curves)
Inferior thoracic bodies resemble bodies of which vertebrae?
lumbar
At their posterior surface, these vertebrae are flattened anteriorly to posteriorly, and they are transversely concave and their anterior and lateral surfaces are concave from top to bottom
lumbar vertebrae
The bodies of these vertebrae are bean-shaped and increase in size from the first to the fifth vertebra in this region, they are deeper anteriorly than posteriorly, and their superior and inferior surfaces are flattened or slightly concave
lumbar vertebrae
The five vertebrae occupying the region of the loin are
lumbar vertebrae
The lumbar and pelvic curves join at an obtuse angle termed the ___________________________________
lumbosacral angle
The superior surface of the base of the sacrum corresponds in size and shape to the inferior surface of the last lumbar segment, with which it articulates to form the _______________________________
lumbosacral junction
A smoothly rounded projection on the back of each superior articular process of the lumbar vertebrae
mammillary process
Is the sacrum longer, narrower, more evenly curved, and more vertical in men or women?
men
Central mass of soft, pulpy, semigelatinous material of the intervertebral disks
nucleus pulposus
In what direction does the tranverse processes of the thoracic vertebrae project?
obliquely, laterally, and posteriorly
Area of lamina between the two articular processes
pars interarticularis
Short, thick processes that project posteriorly, one from each other, from the superior and lateral parts of the posterior surface of the vertebral body
pedicles
The __________________________________ of the typical cervical vertebra project laterally and posteriorly from the body, and their superior and inferior vertebral notches are nearly equal in depth
pedicles
The _________________________________ of the lumbar vertebrae are strong and are directed posteriorly and the ________________________ are thick
pedicles laminae
Each of the anterior and posterior walls of the sacral canal is perforated by four pairs of ___________________________________________ for passage of the sacral nerves and blood vessels
pelvic sacral foramina
Bodies of the typical (third through ninth) thoracic vertebrae are deeper posteriorly or anteriorly and their posterior surface is ____________________________ from side to side
posteriorly concave
The thoracic and pelvic curves are called ____________________________________ because they are present at birth
primary curves
The upper limbs are supported indirectly via the _________________, which articulate with the sternum, and the sternum articulates with the ____________________________
ribs shoulder girdle
A slight lateral curvature is sometimes present in the upper thoracic region and is to the _______________ in right-handed persons and to the ________________ left-handed persons, and because of this the lateral curvature of the vertebral column is believed to be the result of _____________________ and to be influenced by ___________________________
right left muscle action occupation
3 foramina of the cervical vertebrae:
right and left transverse foramina vertebral foramina
Located directly behind the bodies of the sacral segments; is the continuation of the vertebral canal and is contained within the bone and transmits the sacral nerves
sacral canal
Two processes that project inferiorly from the posterolateral aspect of the last sacral segment to joint the coccygeal cornua
sacral cornua
Prominent ridge at the superior anterior margin of the base of the sacrum
sacral promontory
The five vertebrae located in the pelvic region
sacral vertebrae
The vertebral column articulates with each hip bone at the ___________________________, this articulation supports the vertebral column and transmits the weight of the trunk through the hip joints and to the lower limbs.
sacroiliac joints
Curved, triangular bone formed by fusion of the five sacral segments; it is wedged between the iliac bones of the pelvis
sacrum
The sacral segments usually fuse into one bone called the ____________________, and the coccygeal segments, referred to as the ________________________ also fuse into one bone
sacrum coccyx
An abnormal curvature of the spine, this condition causes the vertebrae to rotate toward the concavity
scoliosis
congenital defect of the vertebral column in which the laminae fail to unite posteriorly at the midline
spina bifida
The _____________________________ of the vertebrae projects posteriorly and inferiorly from the junction of the laminae in the posterior midline
spinous process
The ________________________________ of the axis is horizontal in position
spinous process
From the fifth to the ninth vertebrae, the _____________________________ project sharply inferiorly and overlap each other, but they are less vertical above and below this region
spinous processes
The _______________________________ of the lumbar vertebrae are large, thick, and blunt, and they have an almost horizontal projection posteriorly; the palpable tip of each of these corresponds in position with the interspace below the vertebra from which it projects
spinous processes
The __________________________________ of the typical cervical vertebra are short, have double-pointed (bifid) tips, and are directed posteriorly and slightly inferiorly; their palpable tips lie at the level of the interspace below the body of the vertebra from which they arise
spinous processes
Spondylolysis occurring on one or both sides of the vertebra; is characterized by the anterior displacement of one vertebra over another, generally the fifth lumbar over the sacrum; most exclusively involves the lumbar spine
spondylolisthesis
Is an acquired bony defect occurring in the pars interarticularis
spondylolysis
The ________________________________ and ___________________________ of the typical cervical vertebra are located posterior to the transverse processes at the point where the pedicles and laminae unite.
superior and inferior articular processes
Each _______________________________________ has an articular facet on its posterior surface
superior articular process
Located at each side of the dens on the superior surface of the vertebral body; they are adapted to join with the inferior articular processes of the atlas
superior articular processes
The ________________________________________ of the first sacral segment articulate with the inferior articular processes of the last lumbar vertebra to form the last pair of zygapophyseal joints
superior articular processes
What kind of facets do the ninth thoracic vertebrae have?
superior demifacet
Portion of the first sacral segment that remains distinct and resembles the vertebrae of the lumbar region
superior portion
The _________________________________ of each lateral mass of the atlas lie in a horizontal plane , are large and deeply concave, and are shaped to articulate with the occipital condyles of the occipital bone of the cranium
superior processes
Function of the pedicles and laminae of the vertebral arch:
support 4 articular processes, 2 transverse processes, and 1 spinous process
The succeeding 12 bones that lie in the dorsal, or posterior, portion of the thorax
thoracic vertebrae
Ligament that divides the ring formed by the arches of the atlas into anterior and posterior portions
transverse atlantal ligament
The _________________________________ of the vertebrae project laterally and slightly posteriorly from the junction of the pedicles and laminae
transverse processes
The ____________________________________ of the typical cervical vertebra arise partly from the sides of the body and partly from the vertebral arch; they are short and wide, are perforated by the transverse foramina for transmission of the vertebral artery and vein, and present a deep concavity on their upper surfaces for passage of the spinal nerves
transverse processes
The ______________________________________ of lumbar vertebrae are smaller than those of thoracic vertebrae; the superior three pairs are directed almost exactly laterally, whereas the inferior two pairs are inclined slightly superiorly
transverse processes
The _________________________________________ of the atlas are longer than those of the other cervical vertebrae , and they project laterally and slightly inferiorly from the lateral masses
transverse processes
What causes HNP of cervical spine?
trauma or degeneration
Shape of the bodies of the typical (third through ninth) thoracic vertebrae?
triangular
The superior four pairs of foramina are shown with the pt in what position, but the last pair requires what?
true lateral slight obliquity of the body
The 24 vertebral segments in the upper three regions remain distinct throughout life and are termend the __________________________________
true or moveable vertebrae
Cervical vertebrae C3-C6 have a small, transversely located, oblong body with slightly elongated anteroinferior borders
typical cervical vertebrae
Seventh cervical vertebra (C7), has a long, prominent spinous process that projects almost horizontally to the posterior and it is called the _____________________________
vertebra prominens
The vertebral column is composed of small segments of bone called _______________________
vertebrae
Posterior ringlike portion of the vertebra
vertebral arch
In the articulated column, the vertebral foramina form the _____________________________
vertebral canal
Space enclosed by the vertebral body and arch
vertebral foramen
Concave superior and inferior surfaces of the pedicles or roots form the __________________________________
vertebral notches
The body of the first thoracic vertebra presents a _________________________________ near its superior border for articulation with the head of the first rib and presents a _______________________________________ on its inferior border for articulation with the head of the second rib
whole costal facet demifacet (half-facet)
The tenth, eleventh, and twelfth thoracic vertebral bodies have a single __________________________________ at the superior margin for articulation with the eleventh and twelfth ribs
whole facet
Articulations between the articular processes of the vertebral arches Type: Movement:
zygapophyseal joints synovial gliding free movable
The articulations between the articular processes of the vertebral arches are the synovial intervertebral joints, referred to as ________________________________________________
zygapophyseal joints (interarticular facet joints)
