Arthrology of the Vertebral Column Flashcards
What is the latin term for joint?
arthron
What fibrous connective tissue classically fills the joint space in a syndesmosis?
interosseous ligament
What protein fiber is the dense connective tissue primarily composed of?
collagen fibers which give it a whitish color
Besides collagen, what other proteins are ligaments composed of?
elastin fibers which can give a yellowish tinge to the ligament
What are the characteristics of a (amphiarthrosis) symphysis?
limited motion, median plane location, support ligaments both anterior and posterior to the joint, more permanent in longevity than synchondrosis and they occur between bones developing by endochondral ossification
What are the characteristics of type I articular receptors?
located in the superficial layer of the fibrous capsule, resemble Ruffini endings, most numerous in cervical zygapophyses and they monitor the joint “at rest”
What are the characteristics of type II articular receptors?
located in deeper strata of the fibrous capsule, resemble Pacinian corpuscles, most numerous in the cervical spine and monitor the joint during normal range of motion
What are the characteristics of type III articular receptors?
present in collateral and intrinsic ligaments, resemble golgi tendon organs, not initially observed along the vertebral column and monitor extreme joint motion
What is the function of type IV articular receptors?
nociceptive, they monitor pain
Type IVa articular receptors would be present in what locations?
fibrous capsule, articular fat pads, or adventitia of blood vessels
Type IVb articular receptors would be present in what locations?
accessory ligaments in general, dense in the posterior longitudinal ligament of the spine
What are the three modifications of articular synovial membrane?
(1) synovial villi, (2) articular fat pads or Haversian glands, (3) synovial menisci and intra-articular discs
What is the generic function of modifications of articular synovial membrane?
aid in spreading synovial fluid
What is the apparent function of synovial villi?
increase the surface of synovial membrane available for secretion - absorption phenomena
Articular fat pads are most numerous in what location along the vertebral column?
lumbar zygapophyses
Condensed fibrous connective tissue or fibrocartillage projections of the synovial membrane are called ______
synovial menisci or intra-articular discs
Synovial menisci are a feature of what joint examples?
femur-tibia articulation, cervical zygapophyses, and lumbar zygapophyses
What are the layers of the synovial membrane?
outer fibrous layer and an inner (lumenal) cellular layer AKA synovial lamina intima
What are the specific functions of type A synovial cells?
are phagocytic
What is the specific function of type B synovial cells?
secrete proteinaceous substances and hyaluronic acid
What is the common function of type A and Type B synovial cells?
formation and absorption of synovial fluid
What is the source of nutrition for articular cartilage?
blood vessels in the synovial membrane, sinuses of the bone marrow cavity, and from synovial fluid itself
What is unique about the surface of articular cartilage?
a true perichondrium is absent
Which collagen fiber type predominates in articular cartilage?
type II
What is the primary function of bound glycosaminoglycans?
form a network for water retention
Cartilage is able to change shape due to compression, a characteristic known as _______.
deformation
What is implied when cartilage is said to have elastic properties?
cartilage can deform and returns to original volume rapidly, a time independent property
What is implied when cartilage is said to have viscoelastic properties?
cartilage can deform but returns to original volume slowly, a time dependent property
What is the function of articular cartilage?
to provide a wear-resistant, low friction, easily lubricated surface for joint movement
What are the properties of synovial fluid?
it is yellow-white, viscous, slightly alkaline, and tastes salty
Synovial fluids consists of what specific chemical groups?
fats, salts, albumins, and hyaluronate
Which substance in synovial fluid was first thought to be responsible for its viscosity and lubricating behavior?
hyaluronate
What substance of synovial fluid has been proposed to be responsible for its viscocity and lubricating behavior?
lubricin
What are the classifications of synovial joints (diarthroses) based on the number of articulating surfaces?
simple and compound synovial joints
What is a complex synovial joint (diarthrosis)?
within the simple joint or the compound joint, the articulating surfaces are separated by an articular disc (intra-articular disc) or meniscus
What morphological classification of synovial joints is classified as nonaxial?
plane (diarthrosis arthrodia)
What morphological classifications of synovial joints would be classified as uniaxial?
hinge (diarthrosis ginglymus) and pivot (diarthrosis trochoid)
What morphological classifications of synovial joints would be classified as biaxial?
(diarthrosis) bicondylar, (diarthrosis) condylar, (diarthrosis) ellipsoidal, and saddle (diarthrosis sellar)
What morphological classifications of synovial joints would be classified as multiaxial?
ball and socket (diarthrosis enarthrosis), (diarthrosis spheroidal), (diarthrosis cotyloid) are all classifications given to the same type of joint
Diarthrosis ginglymus joints are commonly called ________ joints based on action.
synovial hinge
What is the maximum number of common ligaments identified with a vertebral couple?
eight
What is the reason that nine common ligaments are identified but only eight will be attached at any specific vertebral couple?
the ligamentum nuchae and supraspinous ligaments attach to the spinous tubercles, but only one of these will be identified at a single vertebral couple
What is the number of true intervertebral discs identified in the adult?
twenty-three
In the adult, which vertebral levels will demonstrate a true intervertebral disc?
those between C2 and S1 inclusively
What percent of the vertebral column length is contributed by the intervertebral disc?
twenty to twenty-five percent
What is the percent of intervertebral disc height contribution to cervical region length?
cervical .. 22-25%
What is the percent of intervertebral disc height contribution to thoracic region length?
thoracic.. 20%
What is the percent of intervertebral disc height contribution to lumbar region length?
lumbar.. 33%
What is the cervical nucleus pulposus composed of?
fibrocartilage
What is the water concentration in the lumbar nucleus pulposus at birth and after thirty?
birth… 88%; thirty…70%
What cell is associated with the nucleus pulposus until about age eleven?
notochord cells
What cells are associated with the mature nucleus pulposus?
reticulocyte-fibroblast and chondroblast
Which type of collagen is dominant in the nucleus pulposus?
collagen type II
What is the organizational pattern for collagen fibers in the nucleus pulposus?
they are irregularly oriented and randomly scattered
What is unusual about the cervical annulus fibrosus?
it lacks any lamellar or layered organization
What is the appearance of the cervical annulus fibrosus?
a horse-shoe with the anterior margin thick and the lateral margins tapering to the uncinate processes; the posterior margin is thin
What compensates for the thinness of the posterior part of the cervical annulus fibrosus?
posterior longitudinal-ligament
What is the organization of the lumbar annulus fibrosus?
it has 12-14 concentric cylindrical lamellae
What is the water concentration in the lumbar annulus fibrosus at bith and after thirty?
birth… 78%; thirty…70%
Which type of collagen is dominant in the annulus fibrosus?
collagen type I
What is the organizational pattern for collagen fibers in the annulus fibrosus?
they are parallel with one another in a single lamellus and angled
What is the organization of collagen fibers between lemellae?
collagen fibers will be angled in the opposite direction such that a spiral - counterspiral organization is observed
What is the average angle of collagen fibers within the annulus fibrosus?
they average 50 to 60 degrees
What is the thickest part of the cartilage end plate?
around the periphery
What is the principle type of collagen fiber within the cartilage end plate?
the type II collagen fiber
What is the direction of collagen fibers within the cartilage end plate?
collagen fibers are aligned anterior to posterior
What is the attachment site for collagen fibers of the inner lamellae of the annulus fibrosus?
the cartilaginous end plate
What are the types of receptor endings in the intervertebral disc?
nociceptors and proprioceptors
What is the relationship between size of the intervertebral disc and receptor endings?
the larger the disc, the greater the variety of receptor endings
What is the proposed function of receptor ending density in the anterior part of the intervertebral disc?
they provide feedback during extension
What innervates the annulus fibrosus at the posterior part of the intervertebral disc?
the recurrent meningeal/sinu-vertebral/sinus vertebral nerve
What innervates the annulus fibrosus at the anterior part of the intervertebral disc?
fibers from the ventral primary ramus
What innervates the annulus fibrosus at the lateral part of the intervertebral disc?
fibers from the ventral primary ramus, fibers from the white ramus communicans, fibers from the paradiscal ramus communicans, fibers from the gray ramus communicans
What is the name given to the white ramus communicans which becomes embedded within the annulus fibrosus of the intervertebral disc?
the paradiscal ramus communicans
What is the popular theory of intra-abdominal cavity pressure and intervertebral disc response to weight bearing?
increasing the intra-abdominal cavity pressure will diminish the amount of resistance the intervertebral disc needs to generate by up to 50%
What part of the intervertebral disc will allow distribution of weight over a maximum surface area?
the nucleus pulposus