Spinal Anatomy Flashcards
Articular facets in cervical region are in what plane?
oblique (called zygopophyseal)
Articular facets in thoracic region are in what plane?
coronal
Articular facets in lumbar region are in what plane?
saggital
What do anterior longitudinal ligaments connect?
adjacent bodies and the IVD along anterior aspect
What do posterior longitudinal ligaments connect?
adjacent bodies and the IVD along posterior aspect
What do supraspinous ligaments connect?
adjacent spinous processes along the posterior aspect
What do intraspinous ligaments connect?
adjacent inferior/superior spinous processes
What do ligamenta lava connect?
adjacent lamina
kyphotic
- thoracic and sacral curves
- present at birth
- concavity faces anteriorly
kyphosis
accentuation of a kyphotic curve, i.e. hunchback
usually caused by poor posture or osteoporosis
lordotic
- cervical and lumbar curve
- develop after birth for balance and ambulation
- concavity faces posteriorly
lordosis
accentuation of the lordotic curves, usually caused by weakened tank muscles, obesity or pregnancy
identifying features of C1 or Atlas
- ring-like
- superior facets articulates with occipital condyles
- two lateral masses with articulating facets and large transverse processes for muscle attachment
- no body, pedicles or laminae
- posterior tubercle instead of spinous process
- can rotate on articular processes of C2
- vertebral artery runs along groove on posterior arch
- articular facet for dens on posterior surface of anterior arch
identifying features of C2
- dens projects superiorly
- no uncinate processes (still has semilunar facets)
- deeply bifid spinous process
- superior articular facets of axis are large and face superiorly
- largest and strongest cervical vertebrae
Name facets of the dens and what they articulate with
- posterior articular facet of the dens articulates with transverse ligament of the dens
- anterior articular facet of the dens articulates with anterior arch of the atlas (C1)
What contributes to 25% of the length of the vertebral column?
IVD or intervertebral discs
-% decreases with age due to disc degeneration
Another name for the pelvic bones?
Os coxae
What is Scoliosis?
lateral curvature of the spine
Which are the typical cervical vertebrae?
C3-C6
What are the features of a typical cervical vertebrae?
- oval-shaped vertebral body (smaller than thoracic and lumbar)
- triangular-shaped vertebral foramen
- bifid spinous process
- oblique facets in articular processes
- uncinate processes
What are the features of a typical cervical vertebrae?
- small oval-shaped vertebral body (smaller than thoracic and lumbar)
- large triangular-shaped vertebral foramen
- short bifid spinous process
- short bifid transverse process
- transverse foramen for passage of vertebral artery (C1-6) and vein (C1-7)
- articular facets in oblique plane
- uncinate processes
What type of joint forms between superior and inferior articular facets?
zygopophyseal
Where are IVFs located and what passes through them?
- Posterior to the vertebral foramen between inferior and superior vertebral notches
- spinal nerves
What does the superior vertebral notch and inferior vertebral notch of adjacent vertebrae form?
Intervertebral foramen, or IVF
What are the 3 areas/parts of the occipital bone?
- basilar, located anterior to foramen magnum
- lateral (condylar), located laterally to foramen magnum
- squamous, located posterior to foramen magnum
Describe the occipital condyle
- facet for articulation with C1
- has a medial notch called the Alar tubercle
Where is the alar tubercle located and what attaches to it?
- medially on the occipital condyle
- the alar ligament
The large opening in the occipital bone is called what and what is it continuous with?
- foramen magnum
- continuous inferiorly with vertebral canal
What attaches to the superior nuchal line?
trapezius, sternocleidomastoid, selenium capitis
What attaches to the inferior nuchal line?
rectus capitis posterior major and mine, obliques capitis superior
What attaches to the median nuchal line?
nuchal ligament
What attaches to the external occipital protuberance?
trapezius, nuchal ligament
Where is the external occipital protuberance located?
on the occipital bone at the intersection of the median nuchal line and superior nuchal line
What movements do C3-C7 enable?
- flexion/extension
- lateral flexion coupled with rotation
What movements do C1-C2 enable?
- rotation (C1-C2)
- flexion/extension (C0-C1)
- limited lateral flexion
What joint is formed by the semilunar facet and uncinate process of adjacent cervical vertebrae?
uncovertebral joint
What is the function of uncovertebral joints?
- limit lateral flexion
- guide movement in flexion and extension
Describe the articular facets of the SAP, or superior articular process?
- flat and oval
- face Superior, medial and Posterior
Describe the articular facets of the IAP, or inferior articular process?
- flat and oval
- face Inferior, Anterior and lateral
What runs through the intervertebral foramen?
Vertebral artery and vein (except in C1)
What is the articular pillar?
IAP, SAP and pars interarticularis arranged in a column
What are the parts of the bifid process of a typical cervical vertebrae?
- Anterior tubercle
- posterior tubercle
What is another name for the anterior tubercle of a typical cervical vertebrae and why?
costal tubercle because it transitions to ribs in thoracic vertebrae
What is the purpose of the groove in the transverse process of a typical cervical vertebrae?
where the spinal nerve lies after going through the transverse foramen
Spinal nerves emerge between what in the cervical region?
vertebral artery in the transverse foramen and the zygopophyseal joint, except C1 and C2 nerves
What are the borders of intervertebral foramen?
- intervertebral disc
- adjacent vertebral bodies
- uncovertebral joint
- adjacent pedicles
- zygopophyseal joint
Atypical features of C7
- transitional vertebrae between cervical and thoracic
- inferior articular facets are oriented similar to thoracic vertebrae
- superior articular facets are oriented similar to cervical vertebrae
- spinous process is more prominent and is not bifid
- no semilunar facets (still has uncinate process)
Path of the vertebral artery in the cervical spine?
through the transverse foramen of C7 to C2 where it enters the vertebral foramen of C2 through a groove in the posterior arch, then it turns up and enters the skull through the foramen magnum
What are considered the typical thoracic vertebrae?
T2-T8, sometimes T9
How many thoracic vertebrae?
12
How many cervical vertebrae?
7
How many lumbar vertebrae?
5
Features of a typical thoracic vertebrae?
- non-bifid spinal process that slopes inferiorly
- circular vertebral foramen
- heart-shaped vertebral body that is larger than cervical but smaller than lumbar and thicker posteriorly
- superior and inferior articular facets are in the coronal plane, superior faces posteriorly
- superior and inferior costal demi facets articulate with rib
- transverse costal facets articulate with tubercle of rib
- inferior vertebral notch much larger than superior
What facets do ribs articulate with on typical thoracic vertebrae?
- transverse costal facet on vertebra of same number
- superior and inferior costal demi facets of vertebra of same number and vertebra above, respectively
What direction does the superior articular facet face on a typical thoracic vertebrae?
posteriorly
What direction does the inferior articular facet face on a typical thoracic vertebrae?
anteriorly
What is the difference between IVF in cervical vertebrae and thoracic vertebrae?
The IVF in the thoracic region are oriented laterally whereas the IVF in the cervical region are oriented laterally but also slightly anteriorly
What are the features of T1?
- full superior costal facet that pairs with the 1st rib
- inferior costal demifacet paired with the 2nd rib
- vertebral body resembles the cervical vertebrae (more oval than heart-shaped)
- spinous process is sometimes more pronounced than C7 and is the vertebrae prominens
What are the features of T9?
- usually does not have an inferior costal demifacet, although sometimes does and is therefore sometimes considered a typical thoracic vertebrae
- still has superior costal demifacet
What are the features of T10?
- first thoracic vertebrae with a full costal facet which is paired with the 10th rib
What are the features of T11?
- vertebral body is large and resembles lumbar vertebrae (not heart-shaped)
- full costal facet that is paired with the 11th rib
- no transverse costal facet because rib 11 is floating
- spinous process is short, thick and rectangular: resembles the lumbar vertebrae
What are the features of T12?
- vertebral body is large and lumbar-like
- inferior articular facet faces lateral (instead of anterior)
- transverse process has 3 small elevations
What are the three elevations of the transverse process of T12?
- superior tubercle (mammillary process)
- lateral tubercle (vestigial transverse process)
- inferior tubercle (accessory mammillary process)
Which are the typical lumbar vertebrae?
T1-T4
What are the features of a typical lumbar vertebrae?
- vertebral foramen is triangular
- vertebral body is large and kidney bean-shaped
- have mammillary and accessory mammillary processes
- articular facets are in the sagittal plane
- spinous process is stout and rectangular
- transverse process is long and slender, project laterally
What direction do the superior facets face on a typical lumbar vertebrae?
mostly medial but also slightly posterior
What direction do the inferior facets face on a typical lumbar vertebrae?
mostly lateral but also slightly anterior
What are the features of IVFs in the lumbar region?
- oriented laterally
- largest along the vertebral column
- inferior notch is MUCH larger superior notch
What are the features of IVFs in the thoracic region?
- oriented laterally
- inferior notch is SLIGHTLY larger that superior notch
What are the features of IVFs in the cervical region?
- oriented laterally but also slightly anteriorly
- superior and inferior notches are roughly EQUAL
Which lumbar vertebrae is considered atypical?
L5
What are the features of L5?
- vertebral body is the largest in the lateral dimension but shortest in the A/P dimension of all lumbar vertebrae
- inferior articular are approaching coronal plane, facets face anterior and slightly lateral
- small spinous process
- short transverse process
What are anular epiphysis on vertebrae?
secondary center of ossification of the vertebral body, visible as a bony ring around the superior and inferior surfaces of the vertebral body
A joint with little (if any) movement?
synarthrosis
ex: skull
A joint with slight movement?
amphiarthrosis
ex: vertebrae
A joint with wide range of movement?
diarthrosis
ex: shoulder
A joint where articulating surface is covered by fibrous tissue?
fibrous joint
ex: tooth
A joint where articulating surface is covered by cartilage but nor directly connected?
Synovial joint
ex: knee
A joint where articulating surface is covered and connected by cartilage?
cartilaginous joint
ex: pelvic symphysis (sp?)
Central joints (between vertebral bodies) are what type (tissue and movement)?
cartilaginous
amphiarthrosis
Zygapophyseal joints are what type (tissue and movement)?
synovial
diarthrosis
Central or vertebral body joints are absent where?
occiput/Atlas
Atlas/Axis
Sacrum
Coccyx (usually)
What kind of cartilage is in the IVDs?
Fibrocartilaginous complex with some hyaline cartilage
How are IVDs named?
to include the vertebrae they separate (C5-C6 IVD)
What is the pattern of the cross sectional area of the IVDs throughout the vertebral column?
cross section is least in cervical region and greatest in lumbar region - increases down the vertebral column
How many IVDs are there?
23 - 6 cervical, 12 thoracic, 5 lumbar
What is the pattern of thickness of IVDs throughout the vertebral column?
thickest in the lumbar region and thinnest in the thoracic
Where is an individual IVD thickest?
anteriorly
How do IVDs help form the lordotic curves?
by being thicker anteriorly and thinner posteriorly
What is the center of the IVD called?
nucleus pulposus
What is the outer ring of the IVD called?
anulus fibrosis
What is the function of the anulus fibrosis?
- as a ligament to bind intervertebral bodies
- retain nucleus pulposus
Why are disc herniations more common posterior laterally?
Because IVDs are thinnest posteriorly and posterior longitudinal ligament does not reinforce the posterior lateral portion of IVDs
What is the structure of the anulus fibrosis?
- fibrocartilaginous concentric rings that alternate each layer to form a basket weave for strength
- thinner posteriorly but reinforced by posterior longitudinal ligament
What is the nucleus pulposus made of?
collagen in mucopolysaccharide matrix
-it is the gelatinous remnant of notochord
What are the features of the nucleus pulposus?
it is strongly hydrophilic but held under pressure by gravity when standing or sitting causing it to lose water. When lying down, it gains water. It becomes more dehydrated with age.
Where are vertebral end plates located?
adjacent to upper and lower surfaces of successive vertebral bodies
What are the vertebral end plates made of?
have osseous and cartilaginous parts
Collagen fibers of the anulus fibrosus are continuous with which structure?
vertebral end plates
What is the structure and function of vertebral end plates?
They are porous to allow for transport/diffusion of water and nutrients to the avascular nucleus pulposus of the IVDs and transport/diffusion of waste away from nucleus pulposus of the IVDs
What is the small peripheral rim around the anulus fibrosus?
anular epiphysis