Vertebrae and development Flashcards
regions of vertebral column
7 cervical 12 thoracic 5 lumbar 5 fused sacral 3-5 fused coccyx
why a curved spine
resists compressive loads better
increases flexibility
thoracic and sacral curvature
primary (fetal)
kyphosis
lumbar and cervical curvature
secondary (after birth)
lordosis
atlantooccipital joint
c1 and occipital condyles
no ivd
primarily flexion
uncovertebral joints
uncinate processes of c3-c7 and body superior
common sites of bone spurs
may compress nerve and artery
zygapophyseal joints
articular facet orientation determne range of motion
zygapophyseal joint cervial
promotes flextion/extension
limits rotation - no owl
most mobile region
sloped/near horizontal orientation
zygopophyseal joint thoracic
vertical orientation
promotes rotation
limits flexion
spinous processes restrct each other
zygopophyseal joint lumbar
wrapped orientation
promotes flexion/extension
limits rotation
short spinous processes
intervertebral discs
link adjacent vertebral bodies
increase range of motion
transmits loads from 1 segment to another
cushioning
annulous fibrosis
outer layer of ivd
alternating fiber pattern
limits rotation between bodies
increases joint strength
nucleus pulposus
core of ivd gelatinous adds flexibility and resilience avascular remnant of embryonic notochord
intervertebral foramen
spinal nerve exits
where do cervial nerves exit in the vertebral column
exit superior to vertebrae
where do thoracic and lumbar nerves exit in vertebral column
exit inferior to vertebrae
herniation of intervertebral disc
protrusion of nucleus propulsus into annulus fibrosus
may herniate into vertebral canal and compress spinal cord or nerve roots
posterior herniation
compresses spinal cord
posteriorlateral herniation
compresses nerve roots
what can a herniation cuase if it impinges on spinal nerves
severe local back pain
sensitivity to associated dermatome
associated muscle weakness
what does the sclerotome later become
vertebra and rib bones
describe vertebral column development
mesoderm becomes mesechymal and organizes into segments called somitomeres
paired somitomeres surround neural tube and notochord and further develop into somites
somites migrate around neural tube and notochord to fuse with cells on opposite side
what does the dorsomedial and ventrolateral regions give rise to
muscles
describe the process of resegmentation
each centrum develops from 2 adjacent sclerotomes
portion of caudal cells moves down to fuse with cranial portion of subadjacent sclerotome. to form centrum
