Week 1: Introduction to Spinal Column Flashcards
How many vertebral discs are there?
23
How many vertebra are there?
33
how many cervical vertebra do you have?
7
how many thoracic vertebra do you have?
12
how many lumbar vertebra do you have?
5
how many sacral vertebra do you have?
5
how many coccygeal vertebra do you have?
4
What are 3 functions of the vertebral column?
Provide protection
provide attachment points
meet the demands of mobility and stability of the trunk and extremities
What are the 2 primary or kyphotic curves?
thoracic and sacral
what are the 2 secondary or lordotic curves?
lumbar and cervical
what is the advantage of a curved vertebral column vs. a straight rod?
it increases the ability to resist compressive load
A “functional unit” of the spine consists of:
any 2 adjacent vertebra
intervertebral discs
soft tissues that secures them
A typical vertebra consists of two parts. Anteriorly, we have the vertebral _______ and posteriorly, we have the vertebral or neural ________.
body; arch
The vertebral or neural arch can be divided into:
pedicles and posterior elements
what are the 4 posterior elements of the vertebral or neural arch?
laminae
articular processes
spinous processes
transverse processes
A curved vertebra provides an opportunity for ______ forces to act at:
shear; regions of transitions between curves… ex: C7 - T1
In the case of insufficient cortical bone, what structure is subject to stress fractures?
pars interarticularis
When a stress fracture occurs bilaterally at the pars interarticularis, does this results in a forward or backward slipping of the vertebra?
forward
What is spondylolisthesis?
when a stress fracture occurs bilaterally at the pars interarticularis, resulting in a forward slipping of the vertebra.
Spondylolisthesis most commonly occurs at the ________ secondary to angulation of this segment.
L5/S1
What is the function of the body of a vertebra?
resist compressive loads
What is the function of the pedicle of a vertebra?
transmit bending forces from the posterior elements to the vertebral body
What is the function of the lamina of a vertebra?
transmit forces from the articular, transverse and spinous processes to the pedicles.
What is the function of the transverse processes of a vertebra?
serves as a muscle attachment and provides mechanical layer
What is the function of the spinous process of a vertebra?
serves as a muscle attachment and provides mechanical layer; also serves as a bony block to motion
What is the function of the vertebral foramen of a vertebra?
combined with all segments, forms a passage and protection for spinal cord
What structure composes 20 - 33% of vertebral height?
intervertebral discs
What structure progresses in size from 3 mm in the cervical region to 9 mm in the lumbar region?
intervertebral disc
intervertebral disc size is directly related to:
amount of motion and magnitude of the load that is being transmitted
what are the 3 parts of an intervertebral disc?
nucleus pulposus
anulus fibrosus
vertebral end plate
what is the jelly donut of an intervertebral disc made of?
anulus fibrosus
nucleus pulposus
What is the “pulp like” center of an intervertebral disc?
nucleus pulposus
what is the fibrous outer ring of an intervertebral disc?
annulus fibrosis
the nucleus pulposus is ______% water.
70 - 90
the annulus fibrosus is _____% water.
60 - 70
What are 4 characteristics of the annulus fibrosis?
- it is 60 - 70% water
- made of collagen and elastin
- arranged in 15 - 25 concentric fibers
fibers are oriented 65 degrees from vertical
what are contents of a vertebral end plate (cartilaginous layer)?
covering superior and inferior surfaces
.6 to 1 mm of cartilage in adults
strongly attached to annulus fibrosis but not the vertebral body
What intervertebral disc layer is called the cartilaginous layer?
vertebral end plate
Is the vertebral end plate larger or smaller in children compared to adults?
larger
what are the 4 major functions of the intervertebral disc?
- Separate 2 vertebral bodies and therefore increase available motion
- transmit load from 1 vertebral body to the next
- stabilization of the spine
- provide space between vertebrae for exiting spinal nerves
___% of force is transmitted through the intervertebral disc.
80
what allows for the uniform distribution of force in the intervertebral discs?
fluid property
available motion is a reflection of ratio of ______ height to ________ ______ height.
disc; vertebral
When the ratio of disc height to vertebral height is larger, this will allow for ___________ (greater/lesser) movement
greater
where is the ratio of disc height to vertebral body height the largest?
cervical, then lumbar, then spine
When is disc pressure large?
When the load is in front of you (bending forward)
What effect does slouching have on disc pressure?
it produces larger disc pressure
What type of joints are between the vertebral bodies?
symphysis type cartilaginous joints
what are motions are available at the intervertebral joints?
gliding (AP, ML, and torsional)
distraction and compression
rotation (also called a tilt - AP - lateral direction)
Which structures have a:
gliding motion?
distraction and compression?
Rotation?
Gliding - A and C
Distraction and Compression B
Rotation - E, D, F
what type of joints are zygapophyseal joints?
synovial joints
the zygapophyseal joints are an articulation of superior articulating faces with:
inferior articulating facets of cranial vertebra
What joints contain fibroadipose meniscoids?
zygapophyseal joints
What affects available motion of the articular processes of zygapophyseal joints?
shape and orientation of the articular processes
Which ligament limits extension?
Anterior Longitudinal Ligament
What ligaments limit forward flexion?
Posterior Longitudinal ligament (PLL) Ligamentum Flavum Interspinous Ligaments Supraspinous ligaments intertransverse ligaments
what ligament limits forward flexion specifically in the lumbar area?
ligamentum flavum
what ligament limits forward flexion and reinforces posterior portion of the annulus fibrosis?
Posterior longitudinal ligament
what ligament limits extension and reinforces anterolateral portion of annulus fibrosus and anterior aspect of the intervertebral joints?
Anterior Longitudinal ligament
What is 1 contributing factor to the relatively high incidence of posterolateral disc herniations in the lumbar spine? why?
the narrowing of the PLL. it does not provide as much support to the intervertebral discs here.
Strength of zygapophyseal joint capsules is highest in the _________________ region and at the ____________________ junction.
thoracolumbar; cervicothoracic
zygapophyseal joints are primary restraints to:
cervical rotation
side bending
lumbar rotation
zygapophyseal joints are vulnerable to hyper_________.
hyperflexion
Motions of the vertebral column often appear independent, but at the level of motion segments these motions are often “coupled”. what does this mean?
coupling: consistent association of one motion about an axis with another motion around a different axis.
The concept of “coupling” can best be seen when performing which 2 motions?
lateral flexion and rotation
Coupling patterns vary based on:
spinal posture
spinal curvature
orientation of articulating facets
fluidity/ elasticity/ thickness of the disc
extensibility of the muscles, ligaments and joint capsules
Intervertebral discs are great because they:
- inc. movement between 2 adjacent vertebra
- allows for vertebrae to rock or tilt on each other secondary to deformable disc between them
- adds significant range of motion
- the annulus fibrosus restricts motion
what are the 3 kinematic functions of the intervertebral joints?
determine magnitude of movement
distribute load
create space for movement and passage of the spinal nerve roots
Facet joints determine the __________ of the movement.
direction
Osteokinematics of the spine is:
a description of the movement based on direction of superior segment’s anterior portion
arthrokinematics involve approximation, distraction, sliding and tipping of ____________________ joints.
intervertebral
Arthrokinematics of the facet joints allow for:
approximation/ gapping
sliding
Flexion of the spinal column results in an ________ tilt and ________ glide of the superior vertebra?
anterior; anterior
What motion results in widening of the intervertebral foramen and separation of the spinous processes?
flexion
what motion results in anterior compression of the annulus fibrosus and posterior stretching of the annulus fibrosis?
spinal flexion
Excessive spinal flexion is limited due to:
supraspinous and interspinous ligaments tension in facet joint capsules ligamentum flavum posterior longitudinal ligament posterior annulus ligament back extensors
Spinal extension allow for ___________ tilt and glide of the superior vertebra
posterior
what movement results in narrowing of the intervertebral foramen and spinous processes approximate?
spinal extension
what movement results in posterior compression of the annulus fibrosus and anterior stretching of the annulus ligament?
spinal extension
excessive motion of spinal extension is limited secondary to:
bony contact of spinous processes tension in facet joint capsules anterior longitudinal ligaments anterior anulus fibrosus anterior trunk muscles
Lateral flexion of the spinal column causes a lateral ________, __________ and _________ of the superior vertebra over the vertebra below?
tilt, rotation, translation
_______________ results in widening of intervertebral foramen on the side contralateral to the lateral flexion and narrowing on the ipsilateral side
lateral flexion
_________________ results in compression of the annulus fibrosus on the ipsilateral side of movement and stretching on the contralateral side of movement
lateral flexion
Regarding lateral flexion, why does the direction of rotation differ slightly in different regions?
The orientation of the facets
Excessive movement of lateral flexion is limited secondary to:
annulus fibrosus
intertransverse ligaments
trunk muscles
Kinematic rotation causes ________________ of the contralateral facet joint and _______________ of the ipsilateral facet joint.
approximation; distraction
Kinetics: vertebral column is subject to:
axial compression, tension, bending, torsion, shear
kinetics: ability to resist the loads varies by _________ and depends on:
region! Type/ duration/ rate of loading persons age posture various structural elements (vertebral bodies, joints, discs, muscles, joint capsules and ligaments) integrity of the nervous system
What are the 6 functions of the spinal musculature?
control posture
stabilize axial skeleton
protect spinal cord and internal organs
generate intra - thoracic and intra - abdominal pressure
produce torque for movement of the body
mobility of head and neck for optimal place of eyes, ears, and nose
