Vertebral Column Axial skeleton Functions – Supports trunk – Carries skull – Protects spinal cord Movements – Flexion – Extension – Lateral flexion Shape – limits movement

33 vertebrae 24 separate, mobile 9 immobile No. of vertebrae – Cervical = 7 – Thoracic = 12 – Lumbar = 5 – Sacral =5 – Coxygeal =4

Function of v/c – Resilience (spring) Primary curves – Enlarge pelvic cavity – Enlarge thoracic cavity Secondary curves – Brings head & trunk in vertical line of gravity (erect position e.g. standing, sitting)

Lateral view – Adult = Four curves – Foetus = 1 Primary Curves – Concaved anteriorly – Thoracic – Coccygeal Secondary Curves – Convexed anteriorly – Cervical – Lumbar Primary & secondary curves ascribe to shape of vertebral bodies & i/v discs The i/v discs become thinner with age – Result is more primary curves – Stooped posture

Thoracic kyphosis – Primary Lumbar lordosis – Secondary Scoliosis – Lateral curvature – Wedge-shaped vertebrae – hemivertebrae Abnormal Curves

Kyphosis – Abn post convexity – Usually thoracic region Scoliosis – Convexity to one side – Asymmetric muscle weakness – Abn vertebrae Lordosis – Convex ant curve – Lumbar region p130

BLOCK 14 CERVICAL VERTEBRAE

General Structure of a Vertebra Vertebral body – Anterior – Concave superior surface – Concave inferior surface – i/v discs – Weightbearing – Larger & stronger from superior to inferior – Compact bone – Spongy bone Neural (vertebral arch) – Forms vertebral foramen – A few of the latter forms vertebral canal – Latter houses the spinal cord + meninges 2 pedicles 2 Laminae Notches – Superior vertebral notch – Inferior vertebral notch – 2 vertebral notches form intervertebral foramen

Projections from the vertebral arch Spinous process – Single – Posteriorly – For muscle attachment Transverse process – Double – Laterally – For muscle attachment Articular facets – Superior – Inferior – laterally

Regional Characteristics Cervical Vertebrae Shape – Small, oval Superior border – Lateral free standing lips Vertebral foramina – Large Spinous process – Posterior – Horizontal – Bifid Transverse process – Transverse foramen – Vertebral artery Articular facets – Lower facets face down & ant Movements – Considerable – Flexion, extension, rotation Joints – Less stable – Dislocations common

Typical Cervical Vertebrae Foramen transversarium in transverse processes – For vertebral artery (C1-C6) Bifid spinous process Large vertebral foramen – Triangular – For cervical enlargement of spinal cord – Bodies smaller & wider from side to side

Atypical Cervical Vertebrae C1 – Circular – No body – No spinous process – Articular facets for condyles of skull C2 – Dens / odontoid process C6 – Anterior tubercle of transverse process, the carotid tubercle, is large C7 – Vertebra prominens – Long spinous process – Can be palpated

C1 or ATLAS – Articulates with the occipital condyles of the skull and C2 (or the axis) – The “yes joint” – Large transverse processes called “wings” – Lack of a spinous process

C2 or AXIS – The “no joint” – Broad, narrow spinous process – Dens (or odontoid process) is the body of the atlas (C1) – became detached

The atlanto-axial joint No intervertebral disc between C1 and C2 Position of C2 spinous process in relation to C1 Articulation of the dens (of C2) with C1

Cervical Ligaments

Radiographic Anatomy of the Cervical Spine

Vertebral Numbers and Common Nomenclature Cervical (7): C1-C7 Thoracic (12): T1-T12 Lumbar (5) : L1-L5 Sacral (5) : S1-S5 (fused) Coccygeal (5): fused

General Radiographic Considerations Number Alignment Size Shape Radiopacity