Class 1 - Vertebral column Flashcards
Vertebral column contains ____ vertebrae
list the breakdown
33 vertebrae
7 cervical
12 thoracic
5 lumbar
5 sacral
4 coccygeal
Two functions of the vertebral column
- protects the spinal cord
- supports the trunk (rigid and flexible axis for body - posture and locomotion)
Spinal cord runs through the ______ ______
vertebral foramen
lamina + pedicles =
neural arch/vertebral arch
body + neural arch =
vertebral foramen
Articular facets
connect vertebrae to each other
costal facets
connect ribs to vertebra
ONLY THORACIC vertebrae have costal facets
Intervertebral foramina
formed by superior and inferior vertebral notches
transmits spinal nerve and accompanying vessels
Facets on superior and inferior articular process articulate to form the _______ _______
vertebral column
Characteristics of cervical vertebrae
-Overall small in size, with small bodies
-superior articular facets face superioposteriorly
-inferior articular facets face inferoanteriorly
-large, triangularly shaped vertebral foramen (d/t cervical enlargement of spinal cord
-bifid spinous process
C1 aka
atlas
Atlas (C1) characteristics
-no body (dens of C2 articulates with anterior arch of C1)
-posterior tubercle (no spinous process)
-groove for vertebral artery
C2 aka
Axis
Axis (C2) characteristics
-Dens (odontoid process) sticks up and can be considered the body of C1
-bifid spinous process
Atlanto-axial joint
responsible for rotation (shake head ‘no’)
Atlanto-occipital joint
Responsible for head flexion and extension (nod head ‘yes’)
Jefferson (burst) fracture
center of anterior arch fracture on C1
Hangman’s fracture
fracture of pedicle between articular facets on C2
Characteristics of thoracic vertebrae
-Overall intermediate in size, increasing inferiorly
- no transverse foramen
-small, round vertebral foramen
-spinous pocesses slope posterio-inferiorly, not bifid
-superior facets directed posteriorly
-inferior facets directed anteriorly
Complete costal facet on superior body of
T1
Demi-facet on inferior body of
T1
Demi-facets on superior and inferior bodies of
T2-9
Demi-facet on superior body of _____ only
T10
Complete costal facet on
T11 & T12
Transverse costal facets on
T1-T10
From Rib 2-10 the head of the rib articulates on ____ vertebrae
two
Characteristics of lumbar vertebrae
-Overall large in size, with a large body
-Superior facets face posteromedially
-Inferior facets face anteriolaterally
-No transverse foramen
-Triangular vertebral foramen (superiorly for lumbar enlargement of spinal cord, inferiorly for cauda equina)
-short, sturdy spinous processes
Sacrum is formed by ___ fused vertebrae
5
Sacral canal
continuation of vertebral canal
Coccyx is usually made of ___ ridimentary vertebrae
4
can range between 3-5
20% of vertebral column length is made up of
intervertebral discs
annulus fibrosus
ring of fibrocartilage (outer region of intervertebral disc)
nucleus pulposus
gelatinous mass (inside vertebral disc)
Function of the intervertebral discs (2)
-weight bearing
-shock absorption
Herniation/protrusion of intervertebral discs typically occurs
posterolaterally d/t annulus fibrosus being thin posteriorly, the posterior longitudinal ligament medially provides support.
Mechanism of herniation of intervertebral disc
breakdown of annulus fibrosus causes a leak of nucleus pulposus, compressing the spinal nerve exiting the intervertebral foramen
95% of lumbar disc protrusions occur at the ______ & _______ vertebral levels
L4-L5 and L5-S1
5ligaments of the vertebral column
- anterior longitudinal ligament
- supraspinous
- interspinous
4.Ligamentum flavum - posterior longitudinal ligament
Anterior longitudinal ligament
-strong, broad fibrous band running down anteriorly along the vertebral vodies and IV discs
-prevents hyperextension
Supraspinous ligament
runs down the tips of spinous processes from C7 - the sacrum
Interspinous ligament
Connect adjoining spinous processes
Ligamentum Flavum
-Elastic, yellow bands of tissue connecting laminae of adjacent vertebrae
-Limits flexion
Posterior longitudinal ligament
-Narrower, somewhat weaker
-Runs within the vertebral canal along the posterior aspect of the vertebral bodies and IV discs
-Prevents hyperflexion
Nuchal ligament
-Thick, fibroelastic median band running from the external occipital protuberance and posterior border of the foramen magnum to C7 spinous process
-Attaches to the spinous processes of cervical vertebrae, allows for attachment of back muscles where the spinous processes of cervical vertebrae are shorter
Primary curvatures of the vertebral column
Thoracic and sacral kyphosis (concave anteriorly)
present at birth
Secondary curvatures of the vertebral column
cervical and lumbar lordoses (concave posteriorly)
cervical develops when infant holds up head
lumbar develops when toddler begins standing/walking
Excessive thoracic kyphosis
hunched over
shortened to kyphosis, colloquially called a Hump or Hunch
Excessive lumbar lordosis
Excessive posterior concavity
shortened to lordosis, coloquially called sway/hollow back
Scoliosis
abnormal lateral curvature of the spine
“S” bend to spine
Flexion/extension movements of vertebra occur where
Mostly cervical and lumbar
Lateral flexion/extension movements of vertebra occur where
mostly cervical and lumbar
Rotation movement of the vertebra occur where
mostly cervical and thoracic
Meningeal coverings of the spinal cord (3)
- Dura mater
- Arachnoid mater
- Pia mater
Dura mater
“tough mother”
outermost layer, thigh, fibrous tissue
Arachnoid mater
filmy layer deep to dura mater
Pia mater
layer covering the spinal cord
-Denticulate ligament: anchors spinal cord to dura mater, found at midpoint between two spinal nerves
-Filum terminale: thin piece of pia extending distally; termination of spinal cord
3 spaces associated with the spinal cord
- Epidural
- Subdural
- Subarachnoid
Epidural space
space between vertebral canal and dura mater
Subdural space
potential space, seen when pathologic
space between dura mater and arachnoid mater
Subarachnoid space
space between arachnoid mater and pia mater
-CSF located here
-Lumbar cistern enlargement of subarachnoid space inferior to conus medullaris
Components of CNS
spinal cord and brain
how many pairs of spinal nerves are there
31 pairs
Spinal nerves arise from the spinal cord to form part of the _____
PNS
How many cervical spinal nerves
8
How many thoracic spinal nerves
12
How many lumbar spinal nerves
5
How many sacral spinal nerves
5
How many coccygeal spinal nerves
1
The spinal cord has two enlargements in the _______ and _______ where there are more nerves for innervation of the limbs
cervical and lumbar
Cervical nerves course superior or inferior to their vertebrae?
superior
Thoracic, lumbar, sacral and coccygeal course superior or inferior to their vertebrae
inferior
what is conus medullaris
the spinal cord narrows into a cone shape as spinal nerves “leave”
occurs:
Adults: ~L1-L2
Neonates: ~L4-L5
Dural sac
dura mater surround the cauda equina ending at S2
Filum terminale
Internum: continuation of pia mater, from end of conus medullaris to end of dural sac at S2
Externum (coccygeal ligament): pia invests with dura from S2 to coccyx
Cauda equina
spinal nerve roots
Location for Lumbar puncture (adults)
L4 (+/- 1 level) to enter lumbar cistern
Purpose of lumbar puncture
to collect CSF for evaluating infections (meningitis)
Spinal anesthesia insertion point
L4 (+/- 1 level)
risks leakage of CSF
Location for epidural anesthesia
Either same position as lumbar puncture or in the sacral hiatus ???
External and Internal vertebral venous plexus
-located around vertebrae and in vertebral canal
-internal vertebral plexus is valveless
-potential path for cancer metastasis
