vertebrae Flashcards
name the different cranial parts of the vertebrae
neural spine, mamillary process, cranial artic facet, lamina arch, vertebral canal, transverse process, centrum
name the different lateral parts of the vertebrae
cd artic facet, accessory process, caudal vertebral notch for nerve, centrum and transverse process
how did the vertebral centra evolve
segmental bony centra evolved for extra strength, fish centra often biconcave, amphicoelous, linked to ribs
how did the composite vertebra evolve
in early tetrapods, a complex fusion of vertebral elements - robust to resist torsional strain
explain how movement of vertebra has evolved
sagittal plane flexion allows arching whilst sagittal plane extension allows extending. frontal plane flexion allows bending. there is also axial rotation
explain how vertebrae developed
from sclerotome and endochondral ossification. there are 3 primary centres of ossification
where are the 3 primary centres of ossification
one interstitial in cartilage model of centrum, two appositional around model of the laminae. two cranial and caudal epiphyses
what is the generic number of vertebrae in the dog
cervical 7 thoracic 13 lumbar 7 sacral 3
which type of vertebrae do all species have 7 of
cervical
which species have an unusual number of thoracic and lumbar vertebrae
rabbit
what are intervertebral discs
composite joints, 2 planar synovial joints between articular facets. one unusal symphysis between central discs
what is annulus fiborsus
outer symphysis on the centrum, sclerotome; interwoven fibres which resist tension and torsion
what is nucleus pulposus
gel like vestige of notochord which resists pressure in the centrum
outline the variations along the column
cervical are very mobile, thoracic articulate with ribs and have frontal plane movement, lumbar have sagittal movement, sacrum fused and articulate with pelvis at sacroiliac joint, caudal are v mobile
what are the c1 and c2 vertebrae
c1 atlas yes hinge at skull and c2 axis no pivot at c1-c2 joint
how are atlast and axis joined
centrum and neural spine of c1 incorporated into c2 the former as the dens or odentoid process
what does c1 look like
neural arch with no neural spine, remainds old intercentrum so uniquely nerve c1 exits through lateral foramen
what is the structure of c3-7
short neural spines, two pronged transverse processes, c6 large ventral laminae. c1-6 transverse foramina for vertebral artery
structure of thoracic vertebrae
cranially long neural spines and short transverse processes, caudally they blend into lumbar vertebrae
lumbar vertebrae
long transverse processes, laterally directed, inter transverse synovial articulations in horses
sacral vertebrae appearance?
fusion of 3-5 vertebrae and ribs of s1, articulate with pelvis at sacroiliac joint, kink at lumbosacral joint
caudal vertebrae?
loss of neural spines and arches, then minor>articular>transverse processes until only centrum left. cd4-7 have haemal arches to protect ventral caudal artery.
what is the s-cd1 joint site for
epidural analgesia
how do vertebrae change orientation
neural spines tend to point away from limbs
