Exam II: Back I Flashcards
Vertebral Column Composition
Parts: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, ~4 fused coccygeal
Movements: flexion (bend forwards), extension (bend backwards), rotation, side-bending
Functions:
Support: muscles, body weight, head, transmit forces, and upper limbs
Protection: spinal cord and portions of the spinal nerves
Movement: move upper limbs and ribs, maintains posture, and bending over
Curvatures of the Vertebral Column
Adult: composed of cervical, thoracic, lumbar, sacral/coccygeal curvatures
Primary curvature- concave anteriorly (made by thoracic and sacral/coccygeal)
Secondary curvature- concave posteriorly (made by cervical and lumbar); important for standing upright; curvatures develop to balance the line of gravity from skull to pelvis
Fetal: completely concave anteriorly
Primary curvatures develop in utero
As we grow and walk we form secondary curvature
Features of a Typical Vertebrae
Vertebral arch: lamina meet to form roof of the vertebral arch
Vertebral body, superior and inferior articular processes, pedicles, lamina, spinous processes
Synovial joints between articular processes
Has 4 synovial joints (2 above and 2 below)
Has 2 symphyses (1 above and 1 below) with intervertebral discs
Regional Differences of Vertebrae
Cervical – smaller bones support the weight of the head and are flexible to allow a wide range of head movement; also, the axis is the only vertebra with no vertebral body
Thoracic – larger bones than in the cervical region; more rigid to provide a framework for the ribcage and the torso in order to protect the inner organs
Lumbar – largest bones in the spine; support most of the weight of the upper body and allow for bending, twisting and hip flexion
Features of Cervical Vertebrae
- Body: small and square; wider side-to-side than anterior- posterior
- Vertebral Foramen: large and triangular (for cervical enlargment of the spinal cord
- Transverse Process: have anterior and posterior tubercles (at C6 they are large and termed “carotid tubercles”; have transverse foramina (for vertebral arteries, veins and sympathetic plexus; vertebral artery DOES NOT traverse the foramen at C7)
- Articular Process: superior facets are directed superiorly and posterior; nearly horizontal
- Spinous Process: relatively short and bifid (especially C3 - C5); the spines of C6 and 7 are longer (C7 is vertebra prominens)
- Articular facets are sloped anterior to posterior
Features of the Thoracic Vertebrae
Demifacets- ribs
Circular vertebral canal
Superior and inferior facets are more vertically oriented
- Body: heart-shaped and has costal facets
- Vertebrae Foramen: round and smaller
- Transverse Process/Costal facets: large for articulation with ribs; TV1 - 10 have costal facets
- Articular Process: superior facets are directed posterior and lateral
- Spinous Process: long and projected posterior and inferior
Features of the Lumbar Vertebrae
Lack facets for ribs
Mamillary process on superior articular facet that attaches to muscle
- Body: large and broad; cylindrical
- Vertebral Foramen: large (for lumbar enlargement; but smaller than cervical) and triangular
- Transverse Process: long and slender; include accessory process
- Articular Process: superior facets are directed posterior and medial; includes mamillary process
- Spinous Process: short and sturdy
Features of Sacrum and Coccyx
Fusion
Articulates with pelvis
Sacral foramina: where sacral nerve rami (1-4) exit the vertebral column
Important Landmarks of the Vertebral Column
Spinous process of C7: vertebra prominens; first process you feel on your neck
Spinous process of T3: scapular spine
Spinous process of T7: inferior scapular angle
Spinous process of T12: twelfth rib
Spinous process of L4: iliac crest
Intervertebral Discs
Symphyses between vertebral bodies
Anulus fibrosus- outside fibrous ring and allows for transmission of forces
Nucleus pulposus- gelatinous inside core; thinner posteriorly than anteriorly; absorbs compression
Fibrous cartilage present here
Zygapophysial joints
“ZP”
Plane synovial
Between articular facets
Pars interarticularis: area between superior and inferior articular facets
Cervical Vertebrae: sloped anterior to posterior to allow you to flex and extend your neck
Thoracic Vertebrae: facilitate rotation; vertical ZP
Lumbar Vertebrae: very curved to limit movement, but still do a good amount of flexion and extension; wrapped ZP
Cervical Vertebrae Form Uncovertebral Joints
Aka: Joints of Luchska
Between cervical bodies C3-C6
Synovial joints
upper surfaces of cervical vertebrae are elevated into crests = uncinated processes
Uncovertebral Joints: common site for spur formation, and degeneration may impinge spinal nerves
Spurs/chunks of bone can come out, and if large enough they can impinge the nerves and vertebral artery
Spurs are due to loss of cartilage and then the bone overgrows to compensate and can cause problems with ligaments/ nerves
What goes between the intervertebral foramen?
root of each spinal nerve, dorsal root ganglion, the spinal artery of the segmental artery, communicating veins between the internal and external plexuses, recurrent meningeal (sinu-vertebral) nerves, and transforaminal ligaments
Overgrowth in elderly vertebrae can cause pinching of the nerve within the intervertebral foramen
5 Ligaments that Reinforce the Joints
- Anterior longitundinal
- Posterior longitundinal
- Ligamenta flava
- Interspinous
- Supraspinous
Normal vs. Abnormal Curvatures
Kyphosis /hunch back- elderly and bad posture
Lordosis- pot bellies, pregnant women
Scoliosis – during development can be congenital or due to activity; lateral curvature of the spine