Vertebrae part 1 Flashcards
How is the vert bound together
Bound together by deformable discs
Function of the vert
Provides a rigid but flexible axis for movement
Provides a firm base for suspending structures
allow body to maintain cavities with relative constant shape and size
Provides protection for spinal cord
Vertebral Columnand its 3 pillars of support
1 major pillar located anteriorly
2 minor pillars located posteriorly
1 major pillar
joined together by intervertebral discs forming a continuous flexible pillar
Central axis of body
j
2 minor pillars
Stacking of articular processes joined together at synovial joints
section of the vert
C7
T12
L5
S5 fussed
C4 fused
Spinal Curves
Kyphotic Curves
Lordotic Curves
Kyphotic Curves
Thoracic and sacral regions
Primary curves
Regions of greatest stability
Lordotic Curves
Cervical and lumbar regions
Secondary curves
Regions of greatest mobility
Enhance weightbearing function of vert. column
the lumbar curve at birth
it is a Kyphotic Curve but as we process form crawling it transition to a lordotic curve and allows for more mobility
Cervical Spine
Axial skeleton of the neck
Supports and moves the head - sensory platform
7 cervical vertebrae in humans
what does sensory platform in the cervical spine mean
Both of our eyes are straight ahead w/o the cervical spire we cannot see shit
Thoracic Spine
Suspends the ribs
Supports the respiratory cavity
12 thoracic vertebrae in humans
Lumbar Spine
Lies opposite the abdominal cavity
Allows mobility between the thorax and pelvis
5 lumbar vertebrae in humans
Sacrum
Lies opposite the pelvic cavity
Unites vertebral column with pelvic girdle
5 fused sacral vertebrae
Coccyx
Rudimentary structure in humans- start with a tail and this is gone with time
Lends support to pelvic floor
Fused bodies of 3 to 5 coccygeal vertebrae in humans
Vertebral Body bone type
Thick core of trabecular bone
Vertebral Body function
Functions in supporting and distributing weight
Vertebral endplates
Superior and inferior surfaces of trabecular bone covered with hyaline cartilage
Ring Apophyses of the vert body
(Epiphyses)
Apophyses-ring surrounding the cortical bone, on the top and the bottom
spongy bone of the vert body stress
The crisscrossing of spongy bone is showing the strong parts of the bone
Vertebral Arch- vertebral foramen
Forms vertebral foramen together with vertebral body and protects the neural tissues
vertebral foramen shape
Foramen is triangular in cervical, lumbar and sacral regions and circular in thoracic
Vertebral Arch bone type
Made up of primarily cortical bone
Pedicles form what
Superior and inferior concavities form intervertebral foramen
intervertebral foramen
transmission of spinal nerves
> Ant border- vertebral joint
> Posterior – facet joint
Pedicles location
Form ventral part of vertebral arch
spurring of vertbral joints issues
Spurring can move into intervertebral Foremen
You can also get a disc herniation in the discs which can lead to encroachment into foremen
Laminae
Extend dorsally and fuse in midline
Spinous Process local
Projects dorsally from junction between two laminae
Spinous Process function
Function as levers for back extensors
Spinous Process differnce through regions
Shape and inclination varies with region
Cervical SP
thin and horizontal
Thoracic SP
long with downward inclination
Lumbar SP
thick and horizontal
Articular Processes location
Extend from junctions of pedicles and laminae
Paired Articular Processes
Superior articular processes
Inferior articular processes
Orientation of articular porcesses
Orientation varies with vertebral region
Pars Interarticularis
Region between superior and inferior articular processes
Spondylolysis
has to do with Pars Interarticularis
– defect in pars
Spondylolisthesis
– ant. displacement
Transverse Processes
Project from junctions between pedicles and laminae
Sacrum
Wedge shaped
Formed by fusion of 5 sacral vertebrae
Concave ventrally and convex dorsally
Sacral base - Sacral promontory
ventral projection of the S1 vert body
Sacral Base - Superior articular processes
art w/ the inferior art processes of S5
Sacral Base
Sacral promontory
Superior articular processes
Ala
Ala
the upper part of the lateral part of sacrum, lateral to the first sacral vertebra
Sacral Canal
Triangular shape, contains cauda equina
4 pairs of IVF communicate with 4 pairs of pelvic sacral foramina and 4 pairs of dorsal sacral foramina
Dorsal Surface of Sacrum
Sacral crests - median, intermediate and lateral
Sacral hiatus
Sacral cornua
Inferior lateral angles
Lateral Surface of Sacrum - Auricular surface
Covered with hyaline cartilage
Articulates with innominate bone
Lateral Surface of Sacrum- Areas of ligamentous attachment
Median Sacral crests
formed by fusion of sacral SPs;
4 spinous tubercles project from crest
Intermediate sacral crests
represent fused articular processes
Lateral sacral crests
represent fused TPs
Sacral hiatus
hole at the bottom - the 5 vert did not fuse
S1 vert body males vs. females
larger in males (x)
Ala of the sacrum
large in Females (Y)
larger pelvic cavity
Transitional Vertebrae
Vertebra has some features of both adjacent spinal segments
Typically occurs where morphology of vertebra markedly changes from one level to the next
cervicothoracic
thoracolumbar
lumbosacral
Transitional Vertebrae - Sacralization
L5 (or part of L5) fuses to sacrum
when L5 takes on some of the features of S1
Can get synovial joints forming w/ the sacrum or fusing
Common
Transitional Vertebra - Lumbarization
Imcomplete fusion of S1 to rest of sacrum
less common
anthropolgy
anthropolgy
Intervertebral Discs location
Interposed between adjacent vertebrae from C2/3 to L5/S1
Intervertebral Discs height of the column
20% to 33% of height of vertebral column
anterior elements of the vert is composed of
vert. bodies + Intervertebral Discs
Whats is between C1 and C2
not a inter - disct
does the size of intervertebral disc change
yes thicker in the lumbar region beacsue of more pressure in this location
what are Intervertebral Discs made out of
Fibrocartilaginous
what is the main function of the Intervertebral Discs
Major compression-bearing structures
parts of the Intervertebral Discs
Nucleus pulposus
Annulus fibrosis
Nucleus Pulposus made out of
part of the intervertebral disc
Fine fibrous strands in a proteoglycan gel
Properties of Nucleus Pulposus
viscoelasticity and water imbibement
Imbibement in the necleus pulpsus
Imbibement of water – take in water and swells, being able to preload the disc
Compressing the disc to get rid of the water
viscoelasticity of nucleus pulposus
the timing of the applied force will affect how the muscle responds
Nucleus Pulposus with age
By end of first decade, gel begins to be replaced by fibrocartilage
Eventually (about 60 yrs), nucleus pulposus cannot be distinguished from annulus fibrosus (Sylven)
What does age do to immbibment
Compromises disc’s ability for water imbibement and viscoelasticity
Annulus Fibrosis Composition
outer ring
Concentric laminated bands of fibrocartilage and collagenous fibers
Attachments of Annulus Fibrosis
Inner fibers into cartilaginous endplates
Outer fibers into ring apophyses (Sharpey’s fibers)
where is the Annulus Fibrosis best studied
lumbar spine
Annulus Fibrosis fiber orietation
obliquely to plane of disc
Fibers within same lamina are parallel with each other
Fibers of adjacent laminae are oriented in different directions
Posteriorly, laminae join with each other and fibers run vertically
Annulus Fibrosis with age
Degenerative changes begin after second decade
Fibers lose elasticity (especially posterior fibers)
So vulnerable to tearing
Cervical Discs Nucleus Pulposus
NP fills less than 25% of disc volume at birth and becomes fibrocartilaginous after 2nd decade
Cervical Discs Annulus Fibrosis
Fibers of AF are not organized in separate laminae, but interweave
Posterolaterally (at uncovertebral jts.), no AF
Ant. AF major stabilizer in C-spine
Intervertebral Joint type of joint
Symphysis
Disc forms bond between 2 adjacent vertebrae
Deformation of disc at the intervertebral joint
permits movement between vertebral bodies
Amount of movement directly related to size of disc
Anterior Ligaments of Intervertebral Joint
Anterior longitudinal lig.
posterior ligament of inervertebral joint
Posterior longitudinal lig.
Anterior Longitudinal Ligament
Runs from basilar part of occiput to S1 on anterior aspect of vertebral column
Thickness of ant longitudinal ligment
Thickness varies according to region
cervical spine Anterior Longitudinal
Thin and narrow in cervical spine
thoracic spine Anterior Longitudinal
Thick and broad
lumbar spine Anterior Longitudinal
Broad but thin in lumbar spine, blending with crura of diaphragm
Posterior Longitudinal Ligament location
Runs from body of axis to S1 along posterior aspect of vertebral bodies
Posterior Longitudinal Ligament forms what
Forms protective barrier between spinal cord and vertebral column
lumbar region of the longitudinal ligament
Narrow and denticulated in lumbar region.
Implications for posterolateral disc herniations.
Spread out and attach to the intervert discs
Weakened are of the intervert in the lumbar spine
denticulated meaning
Triangular shaped ligaments that anchor the spinal cord along its length, at each side, to the dura mater
posterolateral disc herniations in the lumbar back
Herniation can encroach on a spinal nerve because the discs are moving into the spinal nerve space
Posterior Longitudinal Ligament when Narrow and denticulated in lumbar region.
Implications for posterolateral disc herniations.
Spread out and attach to the intervert discs
Weakened are of the intervert in the lumbar spine
Facet Joints over all
Synovial joints formed between sup. and inf. articular processes of adjacent vertebrae
Facet Joints enclosed by
Enclosed by fibrous joint capsule
Facet Joint Orientation in the Upper Cervical
Oriented in transverse plane
Movement- rotation
Lower Cervical Facet Joint Orientation
Oriented between frontal and transverse planes
Movement – lateral flexion and rotation (coupled – at the same time)
Facet Joint Orientation Thoracic
Oriented in frontal plane
Movement- side bending
Facet Joint Orientation Upper Lumbar
Oriented in sagittal plane
Movement – flex and extension
Facet Joint Lower Lumbar
Oriented between sagittal and frontal planes
Movement- F and E and resist and anterior displacement
Facet Joint Capsule
Strongest of posterior ligaments
Fairly loose (more so in cervical spine)
Reinforced ventrally by ligamentum flavum and laterally by intertransverse ligaments
Ligaments of Vertebral Arch
Ligamentum flavum
Supraspinous ligament
Interspinous ligament
Nuchal ligament
Intertransverse ligaments
Ligamentum Flavum Connects
laminae of adj. vert. from C1 to sacrum
Ligamentum Flavum is thickcess where
Thickest in L-spine
Ligamentum Flavum is compsoed of
Yellow elastic tissue
Accommodates large changes in intralaminar distance during flexion and extension
Loses elasticity with age – this can be a problem
Intertransverse Ligaments location and movement
Extend between adjacent transverse processes
Blend with intertransverse muscles
Supraspinous Ligament location
Extends from C7 to sacrum (or L5)
Supraspinous Ligament connects to what
Connects tips of SPs
Supraspinous Ligament thicker where
Thicker in L-spine, blending with adjacent fascia
Interspinous Ligament location
Extends between adjacent SPs from C7-S1
Interspinous Ligament thickess where
Thickest in L-spine, fibers having a dorsorostral (diagonal and up) orientation
is Interspinous Ligament lacking in any section
Lacking in C-spine
Interspinous Ligament composition
Thin, compared to supraspinous ligament
Nuchal Ligament location
Extends from C7 to occiput connecting cervical spinous processes
Nuchal Ligament 2 parts
Midline raphe and midline fascial septum
Midline raphe
for origins of trapezius, splenius capitis and rhomboid minor
midline fascial septum
deeper
separates semispinalis capitis
