The Vertebral Column (AP) Flashcards
5 regions of vertebral column (how many vertebrae in each)
- Cervical (7)
- Thoracic (12)
- Lumbar (5)
- Sacral (5)
- Coccyx (4)
4 main functions of vertebral column
- Protection
- Support
- Haematopoiesis
- Movement
Borders of vertebral foramen
- Vertebral body (anterior)
- Vertebral arch (posterior)
Why are vertebral bodies of the lower portion larger?
- Body is weight-bearing component
- Increased weight as you go down
Components of vertebral arch
- Spinous process
- Lamina
- Articular process
- Pedicle
- Transverse process
Distinguishing features of a cervical vertebra
- Triangular vertebral foramen
- Bifid spinous process
- Transverse foramina (for vertebral arteries to travel to brain)
Distinguishing features of a thoracic vertebra
- Circular vertebral foramen
- Spinous process extends inferiorly
- Heart-shaped vertebral body
- 2 demi-facets (for ribs)
- 1 costal facet (for rib)
Distinguishing features of a lumbar vertebra
- Traingular vertebral foramen
- Kidney-shaped vertebral body
Distinguishing features the sacrum
Lateral surface has facets for articulation with pelvis
Distinguishing features of the coccyx
- No vertebral arches
- No vertebral canal
Distinguishing features of the atlas
- No vertebral body
- No spinous process
Facets of the atlas
- Superior articular facet
- Inferior articular facet
- Facet for Dens
What do each of the facets of the atlas articulate with?
- SAF = occipital condyles of skull
- IAF = axis
- FFD = dens of axis
What is the atlas-axis joint secured by?
- Transverse ligament of atlas
- Apical ligament of dens
- Alar ligament of dens
- Longitudinal fibres
Distinguishing features of the axis
- Odontoid process (dens)
- Superior articular facet
Movements of the spine
- Flexion
- Extension
- Lateral flexion
- Medial flexion
- Rotation
4 curvatures of the spine
- Cervical (posterior concavity - secondary)
- Thoracic (anterior concavity - primary)
- Lumbar (posterior concavity - secondary)
- Sacral (anterior concavity - primary)
What maintain the curvatures of the spine
- Extensors of back
- Abdominal flexors
Function of the spinal curvatures
Absorb shock
What is scoliosis?
Abnormal lateral curvature of the spine
What is kyphosis?
Excessive outward curvature of the spine in thoracic region (hunchback)
What is lordosis?
Excessive inward curvature of the spine in lumbar region
How do mobile vertebrae articulate with each other?
- Facet joints (plane synovial)
> Superior articular facets with inferior AFs - Vertebral body joints (2ndary cartilaginous)
> Vertebral bodies lined with hyaline
> Via IVDs
Which ligaments strengthen the vertebral body joints?
- Anterior longitudinal ligament
- Posterior longitudinal ligament
Which ligaments strengthen facet joints?
- Ligamentum flavum (between lamina of adjacent)
- Interspinous ligament (between spinous processes)
- Supraspinous ligament (tips of spinous processes)
- Intertransverse ligament (between transverse processes)
- Ligament nuchae (spinous process to external occipital protuberance)
Which structures protect the spinal cord?
- Vertebral bodies
- IVDs
- Ligaments
- Surrounding muscle
- Meninges
- CSF
Function of IVDs
- Shock absorbers
- Prevent friction
What happens in IVDs as person ages
Nucleus pulposus dries out –> uneven weight distribution –> microfractures –> degeneration of spine
What happens in a herniated disc
- Rupture in annulus fibrosus
- Nucleus pulposus breaks through in posterolateral direction
- Irritates nearby spinal nerves
Function of extrinsic back muscles
- Move upper limbs
- Move thoracic wall
Innervation of extrinsic back muscles
Anterior rami of spinal nerves
Muscles in superficial layer of extrinsic back muscles
- Trapezius
- Latissimus dorsi
- Rhomboid major
- Rhomboid minor
- Levator scapulae
Muscles in intermediate layer of extrinsic back muscles
- Serratus posterior superior
- Serratus posterior inferior
Function of serratus posterior superior and inferior
- S = elevate ribs during inspiration
- I = depress ribs during expiration
Innervation of intrinsic back muscles
Posterior rami of spinal nerves
Action of splenius muscles
- Rotate head to same side
- Extend head + neck
Action of suboccipital muscles
Extend + rotate head
Action of erector spinae muscles
- Extension of spine
- Lateral flexion of spine
