axial skeleton - the spine & ribs Flashcards
what does the superior articular facet of C1 articulate with?
the occipital bone
what does the inferior articular facet articulate with?
articulates with C2
function of the inferior articular facet in C1
allows for majority of movement in the cervical region
what are the bones in the cervical region?
C1-C7
what are the bones in the thoracic vertebrae?
T1-T12
what is another name for the thoracic vertebrae?
dorsal region
what are the bones in the lumbar vertebrae?
L1-L5
what are the bones in the sacral vertebrae?
S1-S5
what does the sacral vertebrae form?
five sacral vertebrae fuse to form the sacrum
what shape is the sacrum?
triangular-shaped
what is the coccyx?
four vertebrae inferior to the sacrum that are fused together to form the tailbone
what is lordosis?
posterior concave curvature of the spine
what is kyphosis?
anterior concave curvature of the spine
which parts of the spine are lordosis?
thoracic & sacral vertebrae
which parts of the spine are kyphosis?
cervical & lumbar vertebrae
what is the purpose of correct posture of the spine?
it minimizes & prevents injury on the joints
what is the invertebral foramen?
a hole in the spine where stuff travels through;
inferior to the pedicule
what is the atlas (C1)?
the most superior vertebra in the cervical vertebrae;
contains no vertebral body or spinous process
what is another name for the C1 vertebrae?
the atlas
what is another name for the C2 vertebrae?
the axis
what does the superior articular facet articulate with in the C1?
the occipital bone
what is the transverse processes of the cervical vertebrae contain?
contains foramina
what are the dens/odontoid process?
a projection of an anterior body found in C2
what does the dens/odontoid process articulate with?
atlas (C1)
what is a common feature of all cervical vertebrae?
the transverse foramen of the cervical vertebrae
what is the shape of the vertebral body in the cervical vertebrae?
small & wide
describe the spinous process in the cervical vertebrae
short, forked, & projects directly posteriorly
describe the vertebral foramen in the cervical vertebrae
triangular shaped
what are the movements of the cervical vertebrae?
flexion/extension;
lateral flexion;
rotation
describe the vertebral body in the thoracic vertebrae
heart-shaped;
superior & inferior costal facets located near pedicle
describe the spinous processes in the thoracic vertebrae
long, sharp, & projects inferiorly
describe the vertebral foramen in the thoracic vertebrae
circular-shaped
describe the transverse processes in the thoracic vertebrae
costal facets for rib tubercle on anterior surfaces
which thoracic vertebrae are the transverse processes NOT found?
T11 & T12
where do the superior facets of the thoracic vertebrae face?
directed posteriorly
what are the movements of the thoracic vertebrae?
rotation;
some lateral flexion;
limited flexion/extension
describe the vertebral body in the lumbar vertebrae
massive & kidney-shaped
describe the spinous processes in the lumbar vertebrae
short, blunt, & rectangular;
projects directly posteriorly
describe the vertebral foramen in the lumbar vertebrae
triangular-shaped
describe the transverse processes in the lumbar vertebrae
thin & tapered with facets found
where do the superior facets of the lumbar vertebrae face?
directed posteromedially
what are the movements of the lumbar vertebrae?
flexion/extension;
some lateral flexion
which cervical vertebrae are considered to be atypical?
C1 & C2
which cervical vertebrae are considered to be normal?
C3-C7
what are characteristics of the cervical vertebrae?
mobility;
requires dynamic stability;
supports the head; prone to chronic condition due to posture
what are true ribs?
ribs 1-7;
attaches directly to the sternum
what are false ribs?
ribs 8-12;
attaches indirectly to the sternum
what are floating ribs?
ribs 11 & 12;
does not attach to sternum
how do false ribs attach indirectly?
attaches onto costal cartilage of true ribs which are attached to the sternum
what do the ribs protect?
heart & lungs
how many ribs are there?
12 ribs
what do the ribs attach onto?
sternum & thoracic vertebrae
which muscles do the ribs serve as attachment sites for?
neck & head muscles
what are the three parts of the sternum?
- manubrium
- sternal body
- xiphoid process
what is the manubrium?
most superior aspect of sternum;
serves as attachment site for ribs 1&2
what is the sternal body?
middle aspect of the sternum;
consists of 4 smaller bones fused together;
attachment site for ribs 2-7
what is the xiphoid process?
most inferior aspect of the sternum;
doesn’t fully ossify until about age 40
what is the costal groove in the ribs?
location for intercostal nerves & vessels;
found on inferior side of rib
what is the angle of the rib?
a sharp curvature that provides elasticity
what is unique about the 1st rib?
it’s atypically shaped
what part of the rib attaches onto corresponding thoracic vertebral column?
head, neck, & tubercle of the rib
what is the sacral promonotory?
the area where the 1st sacral vertebrae bulges into pelvic cavity
what are the transverse ridges?
site of vertebral fusion
what is the apex?
inferior tip of the sacrum
what is the sacral ala?
superolateral aspect of sacrum;
projects laterally to form auricular surface
what is the sacral hiatus?
an inferior opening of the sacral canal
what is the auricular surface?
articulates with pelvic bone to form sacral iliac joint
what is the median sacral crest?
the fused spinous processes of the sacral vertebrae
what is the lateral sacral crest?
fused transverse processes
what is the sacral canal?
extension of the vertebral canal
what is the spinous tubercle?
swelling of bone at the tip of the process
what is the superior articular process?
articulates with inferior articular process of L5 vertebra & disc
which disc is the most commonly injured in the lower back?
disc L5-S1
which joint is responsible for major back pain?
sacral iliac joint
what is the typical intervertebral junction
contains transverse & spinous processes, apophyseal joint, & interbody joint
purpose of the transverse & spinous processes in intervertebral junction
serve as levers for muscles & ligaments & its attachments in intervertebral junction
what is another name for the apophyseal joint?
facet joint
what is the apophyseal joint composed of?
two articulating facets;
capsule;
synovial membrane
function of the apophyseal joint
dictates direction & range of motion in the spine
how many pairs of the apophyseal joint are found in the spine?
24 pairs
describe flexion/extension in the spine
forward and backward bending;
occurs in sagittal plane & medial-lateral axis
describe lateral flexion of the spine
side bending movement to the right or left;
occurs in frontal plane & anterior-posterior axis
describe axial rotation of the spine
rotation or torsion of the spine;
occurs in the horizontal plane & vertical axis
what is the interbody joint?
a symphysis joint that connects a disc to two vertebral bodies
purpose of the interbody joint
absorbs & distributes loads across segments
what is the interbody joint a great source for?
adhesion & stability between segments
what are vertebral endplates?
thin layers of cartilage that cover the inferior & superior aspects of the vertebral body
what do vertebral endplates help with?
nutrition for the disc
what are vetebral endplates vulnerable to?
degeneration
what is the intervertebral disc?
contributes to even load distribution across the vertebrae;
composed of a nucleus pulposus & annulus fibrosis
what is the nucleus pulposus?
inner gelatinous nucleus that gives the disc its elasticity & compressibility
what is the annulus fibrosis?
15-20 layers of collagen that keeps the nucleus in place;
avoids an herniated disc
what is a herniated disc?
protrusion of nucleus pulposus in intervertebral disc into the vertebral canal or a protrusion that pinches into spinal nerve root as its trying to leave the canal
what are structures that limit motion in the intervertebral joints?
disc size;
strength & location of ligaments & muscles;
presence of rib cage;
geometry of vertebrae
purpose of the ligaments of the spine
limits excessive motion;
maintains natural spin curvature;
protects spinal cord
purpose of the anterior & posterior longitudinal ligaments
helps stabilize disc & limits its movements
where are the anterior & posterior longitudinal ligaments located?
anterior: in front of vertebral body
posterior: behind vertebral body
purpose of small intervertebral ligaments
helps support discs
what spinal movements can lead to cervical vertebrae injury?
protraction/retraction
which spinal region is the most stable
thoracic vertebrae
how is the thoracic region so stable?
limited range of motion in individual facet joints;
rib cage restricting motion
where is the atlanto-occipital joint located?
between the cranium and atlas (C1)
what kind of joint is the atlanto-occipital joint?
condyloid synovial joint
movements allowed by atlanto-occipital joint
flexion/extension;
limited lateral bending;
independent motion for the skull from the rest of the spine
describe the articulation of the atlanto-occipital joint
articulation of the convex condyle of occipital bone onto concave superior articular facet of C1
what are the 2 components of the atlanto-axial joint?
- a medial joint
2. facet joints
what is the medial joint in the atlanto-axial joint composed of?
dens/odontoid process;
articular facet;
transverse ligament
what is the purpose of the medial joint in the atlanto-axial joint?
main stabilizer
what can damage from the transverse ligament lead to?
spinal cord damage
where are the facet joints in the atlanto-axial joint located?
between inferior articular facet of C1 & superior articular facet of C2
how much spinal rotation occurs from facet joints in atlanto-occipital joint?
50%
what type of joint is the atlanto-axial joint?
pivot synovial joint
purpose of the alar ligament
restricts rotation & stabilizes head-neck complex
what are characteristics of uncovertebral joints?
don’t help or limit motion;
susceptible to degeneration
how are uncovertebral joints susceptible to degeneration?
from bone spurs forming that limit motion
what is spondylosus?
degeneration of structures that limit L5 vertebrae from slipping forward
what is spindylolisthesis?
when the L5 vertebrae has already begun to slip forward
what does the L5-S1 joint prevent?
prevents the L5 vertebrae from slipping forward by facets oriented in a specific manner