Vertebral Column Flashcards
(23 cards)
How many true vertebrae are there?
24 (pre-sacral)
Still isolated
How many false vertebrae are there?
9 (sacral/coccygeal)
fused
Which 2 curvatures of the spine are primary?
thoracic
sacral/coccygeal
Which 2 curvatures of the spine are secondary?
cervical
lumbar
Which secondary curvature is first to develop?
cervical
How are primary curvatures maintained?
shape of vertebrae
How do secondary curvatures arise?
modification in shape of the IV disc
When does the cervical curvature arise?
2-3 months
when does the lumbar curvature arise?
6-8 months
What causes loss of secondary curvatures in the elderly?
thinning and degeneration of IV discs
Why does lordosis occur in pregnancy?
tilting of pelvis due to bump
Which spinal deformity may result from formation of hemivertebrae?
scoliosis
what are the three components of the juvenile vertebrae?
centrum and 2 hemi neural arches
where is ossification initiated in the centra?
dorsal to the notocord
What area of the spine ossifies first? When does this occur?
T10-L1
9-10 weeks gestation
Is ossification in the spine uni- or bidirectional?
bidirectional
What factor stops ossification in the notocord?
angiogenic inhibiting factors
Why do angiogenic inhibiting factors prevent ossification of of the notocord?
endochondral ossification requires arterial supply
what is intramembranous ossification?
bone arising from mesenchymal template
what is endochondral ossification?
bone arising from cartilaginous template
where are the two initial foci of ossification of the neural arches?
lower cervical/upper thoracic
Lower thoracic/upper lumbar
what is a synchondroses?
primary cartilaginous joint- made of only hyaline cartilage
what is a symphysis?
2 plates of hyaline cartilage with a plate of fibrocartilage in between
