Back Anatomy I (part 2.) Flashcards
What is a symphysis joint? What is it formed by?
a fibrocartilaginous fusion between adjacent vertebrae, intervertebral discs
An intervertebral disc is composed of _______ _______ and the _______ __________
nucleus pulposus, anulous fibrosus
What is the nucleus pulposus? what is its function?
notochord remains, gelatinous and absorbs compressional forces
What is the annulus fibrosus? what is its fucntion?
12 concentric rings of fibrocartilage running in opposite directions, helps to contain the nucleus pulposus
The intervertebral discs make up ______ of vertebral column hieght
25%
there is no _________ ________ between the occiput and atlas and between the atlas and axis
no intervertebral disc
Where is the inferior-most intervertebral disc located?
L5-S1
_________ and __________ change the shape of the nucleus pulposus
load and movement
During flexion and extension the nucleus pulposus serves as a _______
fulcrum
What is creep? Who does it effect?
intervertebral discs undergo slow deformation while subject is under persistent mechanical stress (gravity), all people
What is a disc herniation?
prolapsed disc, comes out of containment
What causes disc herniation?
rupture of annulus fibrosus and the protrusion of the nucleus pulposus
Where will the nucleus pulposus most likely prolapse, why?
posterolaterally, bc annulus fibrosus is the tinnest poosteriorly on either side of the posterior longitudinal ligament
What can happen to the spinal cord if a disc prolapses?
can get compressed
What is sciatica?
a prolapsed disc pushing on the sciatic nerve, causes a sharp electrical pain down the legs
Where are uncovertebral joints located?
C3-C7, between the uncinate processes
What are uncovertebral joints? Where are they located?
small, synovial joint-like structures between the unci of the bodies of the lower vertebrae and the beveled surfaces of the superior vertebral bodies
What are synovial joints characterized by?
the presence of an articular joint capsule and an articular cavity
Where are synovial joints located?
posterolateral margins of the intervertebral discs
What is the function of synovial joints?
stabilizes cervical spine and limits lateral flexion
What provides the major support for the vertebral column
anterior and posterior longitudinal ligaments
Where are the anterior and posterior longitudinal ligaments located?
across the anterior and posterior surfaces of vertebral bodies and intervertebral discs respectively
Where does the anterior longitudinal ligament expand from, what is its function
from occipital bone and anterior tubercle of atlas to anterior sacrum, stability, restricts some rotation and extension
Where does the posterior longitudinal ligament expand from, what is its function
extends from from axis to sacrum, provides stability and limits flexion
What does DISH stand for?
Diffuse ideopathic skeletal hyperstosis
What is DISH?
when the anterior or posterior longitudinal ligament becomes calcified restricting movement
Why is DISH in the posterior longitudinal ligament worse?
can compress the spinal cord
What is the ligament between lamina called?
ligamentum flavum
What are zygapophysial joints?
set of synovial joints between the superior and inferior articulating processes of two adjacent vertebrae
How many zygopophysial joints are located in each spinal motion segment
2
what do synovial joints consist of?
articular hyaline cartilage, articular capsule surrounding an articular cavity, synovial fluid
what does the articular cavity of a synovial joint consist of?
outer fibrous layer of irregular connective tissue and inner synovial membrane that secretes synovial fluid into cavitY
What is synovial fluid composed of?
glycoproteins and blood filtrate from capillaries of synovial membrane
What is weeping lubrication? What is its function?
pressure on articular cartilage squeezing synovial fluid into and out of the cartilage, helps with nourishment
How often does weeping lubrication occur?
every time the individual moves
Each zygophophyseal joint is innervated by _____ (#) _______ nerves
two spinal nerves
Each zygopophyseal joint is innervated by the ____________ branches of the ___________ rami of _________ nerves
medial articular, posterior, spinal
The external occipital protuberance serves as an _____ ________ for the _______ ligament which extends down to C7
anchor point, nuchal
What is the function of the ligamentum flavum, interspinous ligament, and supraspinous ligament?
provide additional vertebral column support
Where does the nuchal ligament extend from and what does it merge with
extends from external occipital protuberance and external occipital crest to tip of C7.
merges with supraspinous ligament
What are the atlantooccipital joints?
synovial articulation between superior articular facets of the atlas and the occipital condyles
What does the atlantooccipital joint function in?
allows for flexion and extension, nodding yes
how many atlanto-axial joints are there? what are they?
3, 2 lateral and 1 median
What is the articulation of the lateral atlanto-axial joints?
joints between articulating processes of axis and atlas
What is the articulation of the median atlanto-axial joint?
joint between the atlas and odontoid process of axis
The atlas and head pivot around the __________ process (allowing for ‘no motion’) held in place by the ________ ligament
odontoid, transverse
What ligaments form the cruciate ligament, what is their function?
transverse and superior/inferior longitudinal ligaments to stabilize the odontoid process
What is the function of the alar ligament
connect odontoid process to occipital condyles
What is the tectorial membrane, what is its function?
superior extension of the posterior longitudinal ligament that covers the odontoid process. addded protection so the odontoid process doesnt impale the spinal cord
Where does the tectorial membrane extend from?
covers odontoid process and ligaments, passes through the foramen magnum and inserts on the floor of the cranial cavity
What is the anterior atlantooccipital membrane, what is its function?
continuation of anterior longitudinal ligament, connects axis to atlas
What does the anterior atlantooccipital membrane connect?
the anterior margin of the foramen magnum and the anterior arch of the atlas
What is the posterior atlantooccipital membrane, what is its function?
continuation of the ligamentum flavum, connects occipital bone with the posterior arch of atlas
What does the posterior atlantooccipital membrane connect?
the posterior margin of the foramen magnum and the posterior arch of the atlas
What is the function of the anterior and posterior atlantoaxial membranes?
connect atlas and axis
What arteries supply the vertebral bodies?
equatorial branches from cervical arteries, and segmental arteries that arise from the aorta
What arteries supply the back muscles and vertebral arches ?
posterior branches of segmental arteries via periosteal branches
Where does the spinal branch of the posterior interocstal artery enter the vertebral canal?
intervertebral foramen
T/F the redicular arteries will anastamose with the longitudinal arteries
false
_______ arteries will anastamose with the longitudinal arteries
segmental medullary
Where do the spinal branches from the cervical and segmental arteries enter the vertebral canal? What do they divide into? What do they supply?
intervertebral foramina, divide into anterior and posterior vertebral canal branches, supply the bone surrounding the vertebral canal and ligaments
What do they radicular or segmental medullary arteries from spinal branches supply?
meninges, spinal cord, and spinal nerve roots
What do the spinal veins from? where do they drain?
external and internal vertebral venous plexuses that drain into segmental veins
What are zygopophyseal joints innervated by?
the medial articular branches of the posterior rami of spinal nerves
what are the structures within the vertebral canal innervated by?
meningeal nerves
What are meningeal nerves?
spinal nerves that re-enter the intervertebral foramina
what does the spinal nerve bifurcate into?
the anterior and posterior rami
what does the posterior rami innervate?
back musculature
Where does the recurrent branch of the meningeal nerve head? What does it innervate after bifurcation?
back into the intervertebral foramen, bifurcates to innervate meninges, ligaments, and bone
