Vertebral Column Flashcards
(43 cards)
Vertebra Body
-weight bearing structure
-Cancellous (inner) and Cortical (outer)
Neural Arch - Pedicles
-increase in size caudally (cervical -> lumbar)
-Transmit forces from posterior elements to the vertebral body
-Defines size/shape of the vertebral canal
Post Elements of Neural Arch
Lamina
- “roof” to protect spinal cord
- Transfer forces through pars interarticularis from the spinous and articular processes to pedicles
Post Elements of Neural Arch
Articular Processes
- connect with the vertebra above/below
- Facet Joint = Zygapophyseal Joint (ZAJ)
- Resist shear, compression, tensile and torsional forces - transmits forces to laminae
Post Elements of Neural Arch
Spinous and Transverse Processes (SP, TP)
- sites for muscle attachments
-spinous process resists compression-transmits forces to laminae
Spondylolysis/Spondylolisthesis
- fracture/fracture w displacement
- fracture to pars interarticularis
- Most frequently at L5-S1
- Increased stress on supporting ligaments and joints
- possible compression of the spinal cord
Intervertebral Discs
- increase in size caudally
- Function: increase available motion and transmit
Intervertebral Discs Innervation
- outer 1/3-1/2 of annulus fibrosis
- Sinuvertebral N.: Surrounding connective tissue and ligaments
Intervertebral Discs Nutrition
- no major arterial branches: metaphyseal capillaries @ endplates
diffusion
Interbody Joint (Cartilaginous)
-sliding
-distraction
-compression
-tilting
Amount of movement varies by region…
-structure (disc, vertebral body, orientation of the ZAJ), ligamentous support(s)
Anterior Longitudinal Ligament (ALL)
-resists extension
-Anterior surface of vertebral bodies from C2-sacrum
-fibers blend with annulus fibrosus
-thickest in lordotic regions
-tensile strength greatest in lumbar (2x PLL)
-May become slackened with degenerative disc disease
Anterior Atlantooccipital & Atlantoaxial membranes
extension of ALL from C2-occiput
Posterior longitudinal ligament (PLL)
-resists flexion
-posterior surface of vertebral bodies from C2-Sacrum
-fibers blend with annulus fibrosus
Ligamentum Flavum
-resists flexion
-posterior surface of the spinal canal
-lamina to lamina from C2-Sacrum
-under constant tension even in neutral
Interspinous ligament
-resists flexion
-connects SP of adjacent vertebra
Supraspinous ligament
-resists flexion
-Cord like, connects tips of SP
Intertransverse Ligament
-resists lateral flexion
-pass between TP
-provide stretch/compression during lateral flexion
Alar ligaments
-resists rotation
- Atlas (C0-C2)
- limit ipsilateral lateral flexion and contralateral rotation
Facet/ZAJ Capsules
-resists forward flexion and rotation
-strongest at transition zones
-Vulnerable in extreme flexion (esp. lumbar)
Coupling
consistent association of one motion about an axis with another motion around a different axis
Pure lateral flexion or pure rotation is rare T or F?
False
only place this is true for the cervical/neck region
Coupling is dependent on…
-spinal posture and curves
-orientation of facets
-fluidity, elasticity, and thickness of intervertebral discs
-extensibility of muscles, ligaments, and capsules
Amount of motion available depends on…
size of the discs
