Spine Flashcards
Functions of the spine?
Structural support – head shoulders chest, connects upper and lower body, provides balance and weight distribution
Protection – spinal cord and nerve roots, internal organs
Base for attachment – ligaments, tendons, muscle
Describe the Cervical vertebrae
7 cervical vertebrae are the smallest vertebrae (C1-C7)
Extend from skull to thorax
Support only the weight of the head(can be small and light)
Small muscles can produce effects by tipping balance one way or the other
sudden fall - these arent strong enough to stabilise (Whiplash)
Describe the thorax verterbrae
Mid-back or dorsal region
Twelve vertebrae - T1-T12
Ribs attached to these
Allows change in volume of thoracic cavity
Immobile
Describe the lumbar vertebrae
Lower back
Five vertebrae: L1-L5
Carries weight of upper body
Larger broader (stress = F/A)
Describe the sacrum of the sacral
➢ Triangular structure
➢ Base of the spine
➢ Connects spine to pelvis
➢ Nerves to pelvic organs
➢ Initially unfused – fuses @ 16-18 yrs, completely fused aged 34
Describe the coccyx of the sacral
➢ Few small bones
➢ Remnant of tail
➢ Attachment of various muscles and
ligaments
➢ Takes weight of person sitting
What does the vertebrae consist of?
Body, neural arch and processes
Describe the verterbal bone
designed to bear mainly compressive loads
Larger caudally as superimposed weight of upper body incr
Bone remodels: Wolffs law - adapts to physical sorrounding(creates more/less bone depending on force applied)
80% of bone cancellous (first to be affected by osteoporosis)
Describe the structue of the vertebra
body transfers weight along the axis of the vertebral column. bodies of adjacent vertebrae are interconnected by ligaments, separated by intervertebral disc
vertebral arch forms the posterior margin of each vertebral foramen. Foramen and successive vertebrae form vertebral canal enclosing spinal chord.
superior articular process articulates with the inferior articular process of a more superior vertebra.
What is the motion unit of the spine?
twovertebrae and their intervening soft tissues
Describe the intervertebral disc
Nucleus Pulposus: Gelatinous mass, rich in hydrophilic (water binding) glycosaminoglycans in young adults.
Annulus fibrous: outer layer composed of fibrocartilage. Withstand high bending and torsional loads due to crisscross arrangement of coarse collagen fibre bundles.
Describe the longitudinal ligaments of the motioning segment
Provide stability to the spine during rest and movement
Resists excessive movements – hyper extension/flexion
Prevents movements in some directions
High % elastin - highly elastic
Describe the facet joints of the motioning segment
- Articulation between superior and inferior facets
- Hinge structure - link vertebrae together
- Synovial joints: surrounded by a capsule of connective tissue - produces a fluid lubricate the joint.
- Jt surfaes coated with cartilage - jts move/glide smoothly against eachother
- Guide intervertebral motion through their
orientation in the transverse and frontal planes
limits motion (determined by orientation of fcts) - Strongest in thoracolumbar and cervicothoracic regions where the curvatures change
- Resist flexion & undertake tensile loading in
the superior portion with axial loading or
extension - Resists rotation in lumbar region
Describe the spinal muscles of the motioning segment
Muscles & ligaments support spine,hold upright,control movement
Muscle attachments on spinous and transverse processes
Skeletal muscles is innervated and under voluntary control – no control over cardiac muscle
Describe the intervertebral disc of the motioning segment
Disc loaded in complex manner - combo of compressive,tensile and shear loads
In comp - pressure in NP 1.5 times the applied load per unit area
Comp load makes disc bulge radially and circumferential stress developed in annular fibres (As NP only slightly compressible)
What are the regional differences of the Vertebrae
