Vertebral Column and Innervation
What are rami communicantes?
extensions to the sympathetic trunk and its ganglia
As the IV disc degenerates, the load shifts to the _____
facet joints
In the lumbar vertebrae, the facets carry __% of the load, while the IV disc carries __% of the load.
facets carry 25%...this is a lot IV discs carry 75%
T or F: the annulus fibrosis has no pain receptors
false
T or F: the posterior longitudinal ligament attaches mainly to the bodies of vertebrae
false - it attaches mainly to the IV discs
T or F: the ligamentum flavum is in the anterior wall of the spinal canal
false: posterior wall of the spinal canal
The supraspinous ligament resists what motion?
flexion
What is the landmark for the L1 dermatome?
inguinal ligament
Spinal nerves exit through the ______ ______
intervertebral foramen
Cervical and Lumbar regions of the spine have what kind of curve?
lordotic (secondary curve)
What is the landmark for the C3 dermatome?
lower neck/root of neck, supraclavicular fossa
The superior articular facet of the which vertebrae face medially?
lumbar
The articulation of the lumbar and the sacrum is the _____.
lumbosacral angle
What vertebral level has a inferior articular facet facing anteriorly (in the frontal plane)?
mid thoracic
Are nerves usually mixed or unmixed? What does this mean?
mixed - they carry both sensory and motor info
Thick IV discs allow for more or less movement?
more movement
Mammillary process serves as an attachment for what muscle?
multifidis - a muscle that helps support the lumbar vertebrae
Mammillary process
process on the dorsal margin of the superior articular process of each of the lumbar vertebrae
What is the landmark for the T4 dermatome?
nipple line
What is a dermatome?
section of skin innervated by a single spinal nerve
Ventral rami innervate what?
skin and muscles, except for the face which is innervated by the cranial nerves
T3 lines up with what part of scapula?
spine of scapula
Name the features of a typical vertebra.
spinous process transverse process vertebral arch (lamina and pedicle) body articular process articular facet (superior and inferior) vertebral foramen intervertebral foramen
T4 lines up with what?
sternal angle
What about the shape of the facets of the ZP joints of the lumbar spine allows for good extension?
superior facets are concave while inferior facets are convex
T1 lines up with what part of the scapula?
superior scapula angle
Name the ligaments of the spine
supraspinous ligament > nuchal ligament ligamentum flavum interspinous ligament anterior longitudinal ligament posterior longitudinal ligament
IV discs are what kind of joint?
symphysis
what does the superior longitudinal band of the cruciate ligament connect
the transverse ligament of atlas to the occipital bone (A in diagram)
Which spinous processes contain a pars interarticularis
thoracic, lumbar, cervical
C4 lines up with what cartilage?
thyroid cartilage
What is the landmark for the C4 dermatome?
top of shoulder, acromioclavicular joint region (lateral/top of shoulder)
What is the important ligament for the atlanto-axial joint?
transverse ligament of atlas
what does the inferior longitudinal band of the cruciate ligament connect
transverse ligament of atlas to the body of the axis
What plane are the superior facets of the axis in?
transverse plane
T or F: the anterior longitudinal ligament is stronger than the posterior longtidunial ligament
true
T or F: the posterior longitudinal ligament is innervated by the sinuvertebral nerve
true
What is the landmark for the T10 dermatome?
umbilicus
Describe the angle of thoracic zygapophysial joints.
-Upper T spine: inferior facets angled 45-60 degrees anteriorly -Mid T spine: inferior facets face frontal plane anteriorly, suprior facets face posteriorly -Low T spine: inferior facet faces anterior with slight sagittal turn
Describe the AA joint
-articular facets of C1 and C2 (plane/gliding) -odontoid process of C2 and anterior arch of C1 (medial/pivot) -rotation
describe the ligamentum flavum
-between adjacent lamina -resists hyperflexion and twisting -thickest in the lumbar spine -not continuous -in the posterior wall of the spinal canal
interspinous ligament
-between adjacent spinous processes -weak -resists hyperflexion by keeping vertebrae together
Pars interarticularis
-between the inferior and superior articular processes ON ALL VERTEBRAE -joins the facet joints
describe the Uncovertebral joint
-between uncus and vertebral body above -saddle joint -limits lateral flexion -fully formed by 18, doesnt appear at age 6 -bone spurs in elderly
Describe the AO Joint
-biaxial -convex occipital condyles articulate with concave superior articulate facets of lateral masses on C1 -flexion, extension -some lateral flexion -NO rotation
Describe the transverse ligament of atlas
-broad and thick -connects the lateral masses of the atlas -prevents horizontal displacement of atlas to axis
describe the nucleus pulposis
-cartilaginous -gelatinous -collagen, proteoglycans, water -center of the disc
Unique features of thoracic vertebrae
-costal facets for attachment with ribs -transverse costal facets except on 11 and 12 -overlapping spinous processes
Describe the innervation of ZP joints
-dorsal rami innervates them -each branch supplies 2 joints, and each joint is supplied by 2 nerves -nerve lies on transverse process
anterior longitudinal ligament
-extends from pelvic surface sacrum to anterior tubercle C1 and occipital bone (anterior to foramen magnum) -wide and flat -attaches to bone and disc -resists hyperextension...only ligament that does this
Describe the alar ligament
-extends from the dens to the lateral margins of foramen magnum -limits excess rotation -"check" ligament
describe the annulus fibrosus
-fibrocartilage attached to vertebral bodies -layers of fibrous rings -thicker anterior than posterior -has nociceptors -A in diagram
describe the cruciate (cruciform) ligament
-has 3 parts: transverse ligament of atlas, superior longitudinal band, inferior longitudinal band
Describe the angle of the lumbar zygapophysial joints
-inferior facets face laterally (sagittal plane), superior facets face medially -superior facets are concave while inferior facets are convex (this allows for good extension)
Describe the axis (C2)
-large body with dens -small transverse process -strongest of all C vertebrae -large bifid SP -superior facet in transverse plane
Which has a large body: the atlas or the axis?
Axis
What are the 2 important joints of the vertebral column? What kind of joints are they?
IV disc - symphysis, Zygapophysial (facet) joints -plane synovial
Sinuvertebral rami innervate what?
IV discs and ligaments
L4 lines up with what?
Iliac crest; bifurcation of aorta
Describe the location of the spinous processes in the cervical region of the vertebral column.
In the cervical region, the spinous processes are at the level of the facet joints.
Describe the location of the spinous processes in the lumbar region of the vertebral column.
In the lumbar region, spinous processes are slightly below the transverse processes, but at the level of the vertebrae.
True or Fase: there is lots of movement in all planes for cervical zygapophysial joints
True
True or False: There is a difference between dermatomes and cutaneous innervation.
True - Plexuses cause this discrepancy.
T or F: T1-T12 nerves are the same for dermatomes and cutaneous information.
True: these nerves do not enter plexuses.
Which is the most prominent of all vertebrae?
Usually C7, sometime T1
Do cervical spinal nerves exit above or below the vertebrae?
above - this is why we have only 7 cervical vertebrae but 8 cervical spinal nerves.
Which ligament has an attachment on the dens? Alar Ligament, Cruciate Ligament, Supraspinous ligament?
alar ligament
The outside of the intervertebral disc is called the
annulus fibrosus
What does the dens articulate with?
anterior arch C1
The Annulus Fibrosis is thicker anteriorly or posteriorly?
anteriorly
What is the landmark for the C2 dermatome?
back of head (external occipital protuberance)
Do Thoracic, Lumbar, Sacral, and Coccygeal nerves exit above or below the vertebrae?
below
describe the tectorial membrane
continuation of PLL
Sensory refers to ______ information.
cutaneous information
Dorsal Rami innervate what?
deep back musculature and facet joints *they are short*
What is a myotome?
a muscle group/action innervated by a single spinal nerve
What is proprioceptive information?
-where in space is the muscle -how much tension is on the muscle
What is the cauda equina?
"bundle of spinal nerves and spinal nerve roots, consisting of the 2-5 lumbar nerve pairs, the 1-5 sacral nerve pairs, and the coccygeal nerve" Wiki
How many vertebrae are there? Which are fused?
*33 total* 7 C 12 T 5 L 5 S (fused) 4 Co (fused)
How many pairs of spinal nerves are there? How many in each region of the spine?
*Total: 31* 8 cervical: C1-C8 12 thoracic: T1-T12 5 lumbar: L1-L5 5 Sacral: S1-S5 1 Coccygeal: Co1
Describe the angle of Cervical Zygapophysial joints
-C1-C2 joints are mostly on the horizontal plane. -*As we move down the cervical spine, the inferior facets angle more anteriorly, while the superior facets angle more posteriorly. * -Inferior facets 30-45 degrees anteriorly towards coronal plane off of transverse plane. -C7-T1 is about 45 degrees.
Unique features of cervical vertebrae
-C1: atlas -C2: axis -three openings or foramina: 1 vertebral foramina and two transverse foramina. -ant and post tubercles on transverse processes -C2-C6 bifid spinous process -groove for spinal nerve -uncus
Unique features of lumbar vertebrae
-largest of all kinds of vertebrae -absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body -pars interarticularis (more important clinically on lumbar, but is on all vertebrae) -mamillary process
Describe the movement allowed by the zygapophysial joints in the lumbar vertebrae
-more extension, some flexion -limited rotation due to vertical facets -more freedom inferiorly
Describe the atlas (C1)
-no body or spinous process -post and ant arch tubercle -groove for vertebral artery in posterior arch -superior facets are concave in transverse plane
Describe the zygapophysial joint
-plane joint -between superior and inferior articular facets -close to interverterbral foramina -angles of facet help dictate amount of movement possible...(ex. horizontal facets favor rotation)
posterior longitudinal ligament
-posterior surface of body -runs sacrum to skull -attaches mostly to IV disc -resists hyperflexion -sinuvertibral nerve -weaker than Anterior L L -has nociceptors
Describe the supraspinous ligament
-runs along the tip of the spinous processes from the sacrum to C7 -at C7 its name changes to the nuchal ligament -nuchal ligament runs from C7 to the skull -it resists flexion
describe the innervation of IV joints
-sinuvertebral nerves (meningeal nerves) -innervates outer annulus fibrosus, but also posterior longitudinal ligament, anterior longitudinal ligament, spinal canal -carries sympathetic and afferent fibers
Describe the motion allowed by the ZP joints in the thoracic vertebrae
-slight rotation, limited motion due to ribs -some lateral flexion -limited flexion and extension
Name the craniovertebral joints
1. Atlanto-occipital (AO) jt 2. Atlanto-axial (AA) jt
What are the 3 important craniovertebral ligaments
1. alar ligament 2. cruciate ligament 3. tectorial membrane
How many pairs of cranial nerves are there?
12
IV discs in the C spine make up what percentage of the height?
25%... this is a lot compared to other regions of the spine
Which joint allows for head rotation
AA
Which joint allows for head nodding
AO
What merges to form the spinal nerves which exit the intervertebral foramen?
Anterior (sensory) root and Posterior (motor) root
What are the 4 plexuses we need to know? What nerves enter those plexuses?
Cervical plexus (C1-C4) Brachial Plexus (C5-T1) Lumbar Plexus (L1-L4) Sacral Plexus (L4-S4)
C2 lines up with what facial feature?
C2 lines up with mandible
Pain from inflammation in a facet joint would be brought to the spinal cord by what nerve?
Dorsal Rami
T or F: IV joints are thinner (height wise) inferiorly
FALSE - IV joints are THICKER inferiorly. Thickest in the lumbar - helps absorb shock.
T or F: All ventral rami enter plexuses.
FALSE - some ventral rami enter plexuses and some don't.
The spinal cord ends at what vertebral level?
L1/L2
What vertebra lines up with the subcostal plane?
L3
Which spinous processes are short, sturdy, and "hachet" shaped
Lumbar
Which spinous processes contain a mammillary process
Lumbar
IV discs have 2 parts - what are they?
Nucleus pulposus annulus fibrosus
Summarize how the angles change between the zygapophysial joints throughout the spine.
Occipital facets face inferiorly (are horizontal), and C1-C2 are in horizontal plane as well. As the cervical spine descends, the inferior facets angle more anteriorly (between 30-45 degrees) while the superior facets angle more posteriorly. Throughout the thoracic spine, the inferior facets continue to rotate anteriorly and the superior facets continue to rotate posteriorly. At the top of the T spine the inferior facets are between 45-60 degrees. By the middle T spine (T7/T8) the inferior facets face completely anterior in the coronal/frontal plane with the superior facets facing completely posterior in the frontal plane. The lower T spine is the start of a slight sagittal turn in the anteriorly facing inferior facets. T 12 has a sharp transition, with its inferior facet facing laterally, articulating with the superior facet of L1 facing medially. In the Lumbar spine, inferior processes face laterally, and superior processes face medially until L5. L5 inferior facet has another sharp transition to face anteriorly, articulating with S1's superior facet which faces posteriorly.
S2 lines up with what?
PSIS
What happens at the articulation in the zygapophysial joint between L5 and S1?
Sharp transition L5 inferior facet faces anteriorly S1 superior facet faces posteriorly
What is inside your vertebral foramen?
Spinal cord and Cauda Equina
T or F: Root > Nerve > Rami
T
What vertebrae do the intercostal nerves come from?
T1-T11
Describe the location of the spinous processes in the thoracic region of the vertebral column.
T1-T3: spinous processes in same plane as transverse processes T4-T6: spinous processes project downwards, the tip is 1/2 of the way between its own transverse process and the transverse process below T7-T9: spinous processes at level of transverse process below it
What vertebrae does the subcostal nerve come from?
T12
What happens to the angle of the T12 zygapophysial joint articulating with L1?
T12 inferior facet faces sagittal plane outwards/laterally L1 superior facet faces sagittal plane medially
What nerves have no plexus?
T2-T12
Which spinous process matches up the the spine of the scapula?
T3
What vertebral level is the apex of the thoracic kyphotic curve?
T6-T7
What vertebrae do the thoracoabdominal nerves come from?
T7-T11
Which spinous process is found in the same transverse plane as the vertebral body below it? C6, T2, T5, T8, T12?
T8
T or F: motor nerves also contain proprioceptive info
TRUE
T or F: the ligamentum flavum is thickest in the lumbar spine
TRUE
Are we born with kyphotic or lordotic curves? Which one develops over time?
We are born with kyphotic curves, while lordotic curves develop over time.
What continues on past the end of the spinal cord?
cauda equina
Which spinous processes have a narrow intervertebral foramen?
cervical
Spinal nerves may split into what 4 kinds of rami?
dorsal (posterior) rami rami communicantes sinuvertebral rami ventral (anterior) rami
What is the subcostal plane?
imaginary plane just below the 10th rib
T7 lines up with what?
inferior angle of scapula
The Uncovertebral joint is also known as the
joint of Lushka
Thoracic and Sacral regions of the spine have what kind of curve?
kyphotic (primary curve)
Uncovertebral joints limit what kind of motion?
lateral flexion
What ligament attaches the lamina, and what does it prevent?
ligamentum flavum, prevents flexion
what is another name for the nuchal ligament
ligamentum nuchae
T10 lines up with what?
xiphosternal joint