Skeletal System 7.7

vertebral column

vertebral column

extends from the skull to the pelvis and forms the vertical axis of the skeleton

composed of vertebrae, separated by pads of fibrocartilage called intervertebral discs

supports the head and trunk of the body

protects the spinal cord

a typical vertebra

body, pedicles, laminae, spinous process, vertebral foramen, transverse processes, superior and inferior articular processes and intervertebral foramina

what happens if the laminae of the vertebrae do not unit during development

the vertebral arch remains incomplete, causing a condition called spina bifida

transverse processes

project laterally and posteriorly

ligaments and muscles attached to the dorsal spinous process and the transverse processes

projecting upward and downward from each vertebral arch are superior and inferior articular processes

cervical vertebrae

the transverse processes of only the cervical vertebrae have transverse foramina, which are passageways for blood vessels to and from the brain

spinous processes of second through sixth cervical vertebrae are uniquely forked (bifid) .. provides attachments for muscles

seventh cervical vertebra called the vertebra prominens bc it’s more prominent than those of the first six cervical vertebrae. easily found at base of neck + serves as landmark for locating other vertebral parts

atlas

first vertebra

supports the head

no body or spinous process

appears as a bony ring with two transverse processes

axis

second cervical vertebra

bears toothlike dens (odontoid process) on its body

lies in the ring of the atlas

thoracic vertebrae

each T vertebrae has a long, pointed spinous process which slopes downward

thoracic vertebrae except T10-T12 have two costal facets that articulate with ribs

lumbar vertebrae

larger and stronger bodies to support more weight than the vertebrae above them

sacrum

triangular structure composed of five fused vertebrae that forms the base of the vertebral column

spinous processes of these fused bones form a ridge of tubercles

to the sides of the tubercles are rows of openings, the posterior sacral foramina, which nerves and blood vessels pass through

coccyx

tailbone

lowest part of the vertebral column

typically composed of four fused vertebrae

A - pedicle; B - lamina

spinous process

how many vertebrae of cervical, thoracic, and lumbar?

7 cervical

12 thoracic

5 lumbar

two plates called lamina arise from the pedicles and fuse in the back to become a ___

spinous process

A - body
B - pedicle
C - lamina

D - vertebral foramen

what structure of a typical vertebra projects laterally and allows for ligament and muscle attachment?

transverse process

in a vertebra, two plates called ___ extend from the pedicles and fuse into a spinous process.

laminae

what structure is only found in the cervical vertebrae and not in other vertebrae?

transverse foramina

atlas

what structure on the axis projects upwards and allows for rotation or turning of the head?

dens

spinal nerves pass through the ____ foramina of the vertebral column.

intervertebral

which is the dens or odontoid process

B

characteristics of cervical vertebrae

transverse foramina

bifid spinous process

what type of vertebra?

thoracic vertebra

how does the spinous process of a thoracic vertebra differ from those of other vertebrae?

it is long and points downward

in the sacrum, the vertebral foramina of the fused vertebrae form what structure?

sacral canal

body of a lumbar vertebra