Lecture 2- Intro to the Vertebral Column, Cervical Spine, Temporomandibular Joint Flashcards
How many total vertebrae are there?
How many intervertebral discs are there?
- 33 (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal)
- 23
Where are the two primary kyphotic curves located?
Where are the two secondary lordotic curves locates?
- thoracic, sacral
- cervical, lumbar
Why is our vertebrae curved?
Helps to resist compressive forces
What is the drawback of our vertebrae being curved?
It can create shearing forces, particularly at curve transitions
What is the motion segment and what does it consist of?
- It is the functional unit of the spine
- Consists of 2 adjacent vertebrae, intervertebral disc, and the soft tissue connecting them
The typical vertebrae consists of what 2 parts?
- Vertebral body
- Vertebral (Neural) arch
What makes up anterior portion of the vertebral arch?
What makes up the posterior portion of the vertebral arch?
- Pedicle
- Lamina, articular processes, spinous and transverse processes
The shell of the vertebrae is made up of what type of bone?
The interior of the vertebrae is made up of what type of bone?
What is the purpose of this structural formation?
- Shell=cortical
- Interior=cancellous
- Allows for minimal weight of the vertebrae while also allowing for weight bearing due to the shell.
What is the role of the vertebral body?
weight bearing portion of spinal column
What is the role of the pedicles?
transmit tension and bending forces from posterior elements to vertebral body
What is the role of the laminae?
- connects spinous and transverse process
- connects inferior and superior articular processes
What is the role of the articular facet processes?
connect vertebrae together forming the articular pillar
What is the articular pillar?
Combination of multiple vertebrae and their superior and inferior articulations
What is the role of the spinous process?
Serves as muscle attachment and provide mechanical lever; may also serve as bony block to motion
What is the role of the transverse process?
Serves as muscle attachment and provide mechanical lever
If someone has a part interarticularis fracture, where is this fracture?
Where is this most common?
- at the laminae between the articular processes of the vertebrae
- Lumbar
If someone has a bilateral pars interarticularis fracture, what concerns do you have?
slipping forward of the bone, thus affecting the spinal cord
What is the main job of the vertebral foramen?
Passage and protection of the spinal cord
What percentage of vertebral height is attributed to the intervertebral disc?
20-33%
What is the purpose of the intervertebral disc?
- seperate two vertebral bodies and therefore increase motion
- transmit load from one vertebral body to the next
- stabilization of the spine
- provides space between vertebrae for exiting spinal nerves
What are the components of the intervertebral discs?
- nucleus pulposus
- anulus fibrosis
- vertebral end plate
The nucleus pulposus and anulus fibrosis are mostly composed of what?
Water
- nucleus pulposus is 70-90%
- anulus fibrosis is 60-70%
The anulus fibrosis and vertebral end plate do what?
Help keep the nucleus pulposus inside the vertebral disc
A dysfunction at the vertebral disc that allows the nucleus pulposus to leak out is called what?
Intervertebral disc herniation
What position increases the pressure on the disc the most? The least?
- Disc pressure is large when holding load in front of the body, especially with forward bending
- Lifting a load with knees flexed places less pressure on discs than with knee straight
What makes up the intervertebral joints?
body of 2 vertebrae with intervertebral disc
What makes up the zygopophyseal joint?
superior articular facet and inferior articular facet
What are the 6 main ligaments at the spine?
What do they limit?
- Anterior longitudinal- limits extension and reinforces anulus fibrosus and intervertebral joints
- Posterior longitudinal- limits forward flexion and reinforces posterior anulus fibrosus
- Ligamentum flavum- limits forward flexion, mainly at lumbar
- Interspinous- limit forward flexion
- Supraspinous- limit forward flexion
- Intertransverse limit contralateral lateral flexion
What is the purpose of coupled motions at the spine? Give an example.
- Consistent association of one motion about an axis with another motion around a different axis.
- Example is lateral flexion and rotation. Pure lateral flexion and pure rotation do not occur at any region of the spine. In order for either motion to occur, at least some degree of the other must also occur.
What influences the coupling patterns?
- spinal posture
- spinal curvature
- orientation of articulating facets
- fluidity/elasticity/thickness of the disc
- extensibility of the muscles, ligaments, and joint capsules
What occurs osteokinematically at the spine?
- flexion/extension
- lateral flexion
- rotation
Osteokinematically, the description of movement is based on what?
direction of superior segments anterior portion
What are the arthrokinematic motions that occur at the intervertebral joints with each of the osteokinematic motions?
What arthrokinematically occurs at the facet joints with the osteokinematic movement?
- approximation/distraction
- sliding or gliding
- tipping
- approximation/gapping
- sliding or gliding
Flexion of the vertebrae results in anterior ____ and anterior _______ arthrokinematically. This results in a widening of the intervertebral foramen and seperation of spinous processes and facet joints. This will also result in anterior _________ of the anulus fibrosis and posterior _________ of the anulus fibrosis.
- tilt, glide
- compression, stretching
Extension of the vertebrae results in posterior ______ and posterior _______ of the superior vertebrae. This results in a narrowing of the intervertebral foramen and spinous processes and facet joint __________. This will also result in posterior _______ of the anulus fibrosis and anterior _______ of the anulus fibrosis.
- tilt, glide
- approximation
- compression, stretching
Lateral flexion of the vertebrae results in _______ tilt, _________, and __________ of the superior vertebrae over the vertebrae below. This results in ________ of the intervertebral foramen and seperation of _____ joints on the contralateral side. This also results in ______ of the anulus fibrosis on the ipsilateral side of movement, and _________ on the contralateral side.
- lateral, rotation, translation
- widening
- facet
- compression, stretching
Rotation varies widely by region and results in _________ of the contralateral facet and ___________ of ipsilateral facet joints.
- approximation
- distraction
The vertebral column is subject to what forces?
The ability to resist these loads varies by region and depends on what?
- axial compression
- tension
- bending
- torsion
- shear
- type/duration/rate of loading
- age
- posture
- various structural elements (vertebral bodies, joints, discs, muscles, joint capsules, and ligaments)
- integrity of NS
What is the overall function 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
CERVICAL SPINE
CERVICAL SPINE
What are the 4 divisions of the cervical spine and what vertebrae fall within each division?
Upper Cervical (craniovertebral) -occiput, C1, C2 Lower Cervical -C3 to C7 Atypical Vertebrae -C1, C2, and C7 Typical Vertebrae -C3 to C6
What is unique about C1, C2, and C7?
C1 (Atlas)
-shaped like a ring
-has no vertebral body or spinous process
-has 2 lateral masses seperated by anterior and posterior arch
C2 (Axis)
-anterior portion of the body extends inferiorly
-vertical projection from the superior surface of the body known as the dens
-spinous process is large/elongated and bifid
C7
-largest cervical vertebrae
-has many characteristics of a thoracic vertebrae
-large spinous process
What is the structure of the typical cervical vertebrae?
- body is small
- transverse foramen on transverse process
- intervertebral disc is crescent shaped and thicker anteriorly
- posterior longitudinal ligament “stops” nucleus posteriorly
The atlantoaxial joint has how many articulations, what are they?
- 3
- dens to anterior arch, 2 convex on convex articulations between the inferior and superior facets of C1 and C2
What helps with the biconvex articulations at the atlantoaxial zygopophyseal joints?
Meniscoid- cartilage that offsets and makes articulation more congruent