lecture 3 Flashcards
Spine and Bony Thorax
what is the axial skeleton comprised of?
the skull, vertebral column, bony thorax, hyoid bone
what is the appendicular skeleton comprised of?
pectoral girdle, upper limb, pelvic girdle, and lower limb
what is the spinal column?
composed of stacked vertebrae divided into five regions with normal curvatures and the possibility of pathogenic curvatures
since the spinal cord is divided up into 5 regions, what are they and describe them?
cervical, thoracic, lumbar, sacral, coccygeal
what is the cervical comprised of?
composed of 7 vertebrae
what is the thoracic comprised of?
composed of 12 vertebrae
what is the lumbar comprised of?
composed of 5 vertebrae
what is the sacral comprised of?
5 vertebrae fused together into a bone called the sacrum
what is the coccygeal comprised of?
4 vertebrae fused into 1 or 2 bones called the coccyx
what is something to consider when considering the vertebrae in each region?
there can be variation in vertebrae number in each region
with respect to normal curvatures, what is the curvature of the fetus?
single anteriorly concave curve
how does the curvature of the fetus change as he develops?
cervical and lumbar regions develop convex anterior curves as child begins holding head erect and sitting up and so thoracic and sacral/coccygeal regions maintain concave anterior curves called primary curves, keep in mind that cervical and lumbar region curves are convex anteriorly and are called secondary curves
what causes pathogenic curves?name examples?
it can be due to congenital, disease or postural in origin; scoliosis, hyper kyphosis, hyper lordosis
what is scoliosis?
lateral curvature, most often in thoracic region
what is hyper kyphosis?
exaggerated thoracic curvature (hunchback)
what is hyper lordosis?
exaggerated lumbar curvature (swayback) usually due to carrying extra abdominal weight
what are the components of the typical vertebrae?
body, vertebral arch, spinous process, transverse process, superior and inferior articulating processes, intervertebral disc
what is the vertebral body?
disc shaped anterior portion of the vertebrae and is the weight bearing portion of the vertebrae
what is the vertebral arch?
it extends posteriorly from the body and protects the spinal cord
what are the components of the vertebral arch?
pedicles and laminae
what is the pedicle?
short processes that form lateral portions of vertebral arch
what is the laminae?
flat processes that form posterior portions of vertebral arch
what are the other prominent features of the vertebral arch?
vertebral foramen, vertebral canal/spinal canal, vertebral notches
what are the vertebral foramen?
opening bounded by body and vertebral arch
what are the vertebral canal/spinal cord?
vertebral foramen of all vertebrae stacked together
what are the vertebral notches? what is a significant feature of this part of the vertebrae?
superiorly and inferiorly on each vertebra;) with adjacent vertebra they form an intervertebral foramen which allows passage of a spinal nerve
what are some clinical correlations associated with the vertebral arch?
spinal stenosis and laminectomy
what is spinal stenosis?
abnormal narrowing of vertebral foramen
what is a laminectomy?
removal of one or more of the spinal processes and their supporting lamina or pedicle
what is the spinous process?
projects dorsally from junction of laminae and is the site for muscle attachment
what is the transverse process?
extend laterally from junction of pedicle and lamina site for muscle attachment
what are the superior and inferior articulating processes?
articulate with adjacent vertebrae to limit movement
what is the intervertebral disc?
cartilage located between the bodies of adjacent vertebrae
what is the structure of the intervertebral disc?
annulus fibrosis and the nucleus pulpous
what is the length of the intervertebral disc?
1/4 of length of the nonfused vertebral column
what is a herniated disc?
compresses the spinal cord or spinal nerve
what are the movements between adjacent vertebrae?
flexion, extension, lateral flexion, lateral extension and rotation
what are the unique features of the cervical vertebrae?
each transverse process contains a transverse foramen and transmits vertebral arteries and veins to/from the brain; bifid spinous process; uncinate process
whats the uncinate process? which vertebrate have the uncinate processes?
hook-shaped process on lateral superior surface of bodies that provides more structural support in stacking of vertebrae; C3-T1
what is the C1 also known as?
the atlas
describe the prominent features of the atlas?
1) lacks spinous process and body, has anterior and posterior arches
2) large lateral masses
3) superior articulating facets
4) no intervertebral disc between C1 and C2
what do articulating facets do?
articulate with occipital condyles of the skull to form atlanto-occipital joint
so if we already know what articulating facets are, what do they do?
no rotation at this joint
there are intervertebral discs between C1 and C2, T/F?
false, there are none
what is C2 also known as?
axis
name some features of the axis?
it has the dens/odontoid process also known as the hangman’s bone
what is the dens or odontoid process?
projects superiorly through anterior portion of vertebral foramen of C1 providing a pivot point for rotation
why is the dens also called the hangman’s bone?
trauma can sheer dens, driving it into the medulla oblongata causing instantaneous death