Topic 8 Flashcards
what are the functions of the vertebral column
support upper body weight
protect spinal cord and nerves
allows trunk movement
how many vertebrae in each region of the vertebral column
cervical - 7
thoracic - 12
lumbar - 5
sacral - 5
what forms the intervertebral canals (from intervertebral notch)
where spinal nerves exit the spinal cord
z-joint is behind, pedicle is above and below and IV disc is in front.
what are the joints of the vertebral column
- interbody joint
- zygapophyseal joint
what are the joints of the lower cervical spine
- zygapophyseal joints
- interbody joints
- uncovertebral joints
interbody joint
- modified fibrocartilaginous joint
- IV disc
- vary in thickness and shape in different regions of the vertebral column (lumbar region is thickest because it moves the most and has the heaviest load place on it, and the thoracic region is the thinnest because it moves the least as ribs limit movement.
- is avascular - gains nutrition from the cartilaginous end plate.
- only supplied with nerves at their periphery.
- contributes 25% to the length of vertebral column.
what are the components of the IV disc and their functions
annulus fibrosis - alternating layers of dense regular connective tissue - retain the nucleus pulposus and allow rocking movement and limits sheering movement.
nucleus pulposus - toothpaste like consistency - functions as a shock absorber, rapidly applied loads are temporarily diverted into bracing the annulus fibrosis, distributes forces.
cartilaginous end plate - transmits weight to adjacent vertebral body - function is to transmit weight to adjacent vertebral body, confines nucleus pulposus and annulus fibrosis, has a role in securing nutrition for the disc as there is poor blood supply to the joint.
describe the lumbar region of the interbody joints
annulus fibrosis consists of alternating layers orientated 65-70 degrees to vertical.
is thicker anteriorly
describe the cervical regions of the interbody joints
nucleus pulposus is very small and has disappeared by early adult life.
annulus fibrosis develops horizontal fissures beginning in adolescence.
what are the functions of the different muscle fiber directions for interbody joints
oblique orientation of annulus fibers means that shear movements in every direction is limited.
length of annulus fibrosis fibers allows rocking movements.
functions of the interbody joints
weightbearing is the main function of the interbody joints.
weightbearing load causes radial expansion of the nucleus pulposus and causes tension in the annulus fibrosis.
this results in the transmission of load to adjacent vertebra via the end plate, shock absorption, increased effectiveness of annulus fibrosis in weightbearing and reformation of intervertebral disc.
describe how the interbody joints contribute to the curvature of the vertebral column
the normal curvature functions to increase shock absorbing function of the vertebral column.
the thoracic/sacral region is kyphotic which is a primary/structural curve.
the cervical/lumbar region is a lordotic curve which is a secondary/functional curve.
describe the development of vertebral column curvature
babies are born with kyphotic vertebrae and as we grow and gain had control we develop a cervical lordosis curve. after that when babies begin to crawl and sit up they develop a lumbar lordosis curve.
where is the line of gravity in the vertebral column
LoG passes through the junctions of normal vertebral column curves.
zygapophyseal joint
synovial, multiaxial, plane
articular surfaces - superior and inferior articular facets of adjacent vertebrae.
functions - to determine the direction of the vertebral column movement, to determine the range of vertebral column movement and to bear weight (67& in cervical region, 15% in lumbar region).
what are the movements of the vertebral column
movements are determined by the articular triad - which is the interbody joint + zygapophyseal joint of each vertebrae level.
the movements are flexion/extension, right and left lateral flexion and right and left rotation.
segmental range of movement is small but total range is large
describe the movements of the cervical region of the vertebral column
C3-C7
superior articular facets tipped forward from coronal plane
conjunct rotation - ipsilateral coupling with lateral flexion.
large range of flexion/extension
intervertebral disc degeneration can occur.
describe the movements of the thoracic region of the vertebral column
superior articular facets close to the coronal plane
equal range movements in all directions
all movements limited in range due to ribs.
describe the movements of the thoracic region of the vertebral column
superior articular facets close to the coronal plane
equal range movements in all directions
all movements limited in range due to ribs.
describe the movements of the lumbar region of the vertebral column
J shaped superior articular facets in upper lumbar region (coronal and sagittal sections)
very very limited rotation (sagittal portion)
protection for intervertebral disc (coronal plane).
what are the ligaments of the vertebral column
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
supraspinous ligament
interspinous ligament
intertransverse ligament
anterior longitudinal ligament
limits extension
extends from CI to sacrum attaching to anterior surfaces of vertebral bodies and disc.
broad and strong - outer fibers span 3-4 segments, inner fibers span 1 segment.
posterior longitudinal ligament
extends from C2 to sacrum attaching to posterior surfaces of margins of vertebral bodies and discs (separated from vertebral bodies by venous plexus).
weak and narrow in lumbar area.
ligamentum flavum
contains a significant amount of elastic tissue, connects laminae of adjacent vertebrae, passes from the posterior surface of lamina of one vertebra to the anterior surfaces of the lamina of vertebrae above.
attaches to anterior part of capsule of zygapophyseal joints.
functions - “brake” flexion, protects zygapophyseal joint capsules, protects neural tissue.
