VERTEBRAL COLUMN

Gross Anatomy 28 inches in length 28 inches in length Medial border of scapula: Medial border of scapula: Runs parallel to vertebral column Crosses ribs 2-7

Vertebral Column Regions Cervical (7) Cervical (7) Thoracic (12) Thoracic (12) Lumbar (5) Lumbar (5) Sacral (5) Sacral (5) Coccygeal (3-4) Coccygeal (3-4)

Primary Normal Curvatures Present at birth Present at birth Convex posteriorly Convex posteriorly Examples: Examples:ThoracicSacral Exaggeration: Exaggeration:Kyphosis

Secondary Normal Curvatures Acquired later Acquired later Concave posteriorly Concave posteriorly Examples: Examples:CervicalLumbar Exaggeration: Exaggeration:Lordosis

Curvatures Scoliosis Scoliosis Spondylosis: Spondylosis: Refer to text: p 496

Intervertebral Articulations Disc (symphysis) Disc (symphysis) Synovial Synovial Sacroiliac: Sacroiliac: Part synovial and part fibrous Costal facets and demifacets Costal facets and demifacets

Disc (symphysis) 20-30% of length of the column 20-30% of length of the column Thicker in cervical and lumbar regions: Thicker in cervical and lumbar regions: Greater flexibility Thinner in thoracic region: Thinner in thoracic region: Reduced flexibility Structure: Structure: Annulus fibrosus (fibrocartilage) Nucleus pulposus (avascular)

Synovial Joints Plane joints Plane joints No joint capsules No joint capsules Between superior and inferior articulating facets: Between superior and inferior articulating facets: Direction of motion determined by orientation of facets

Motion Segment Functional unit of the spine Functional unit of the spine Consists of: Consists of: Two vertebrae Intervening soft tissue Anterior segment: Two bodies, disc, longitudinal ligaments. Posterior segment: Two neural arches, apophyseal joints, intervening ligaments.

Cervical Vertebrae Transverse foraminae: Transverse foraminae: For vertebral arteries Oblique articular facets Oblique articular facets C2-C6 spines usually bifid C2-C6 spines usually bifid C7 = vertebra prominens C7 = vertebra prominens C1 = atlas C1 = atlas C2 = axis C2 = axis

Thoracic Vertebra Have ribs attached: Have ribs attached: Bicipital ribs: To centrum To transverse process Centrum is heart-shaped Centrum is heart-shaped Articular facets more horizontal Articular facets more horizontal Spinous processes longer and narrower Spinous processes longer and narrower

Typical Thoracic Vertebra Has two costal demifacets on body: Has two costal demifacets on body:Superior: For articulation with head of own rib. Inferior: For articulation with head of inferior rib. Has costal facets for tubercle of rib on transverse process for own rib. Has costal facets for tubercle of rib on transverse process for own rib.

Atypical Thoracic Vertebrae #1: #1: Complete costal for own rib. Inferior costal demifacet on body for rib 2. #10: #10: Complete costal facet on pedicel and body. May have costal facet on transverse process. #11, 12: #11, 12: Costal facet on each pedicle. No costal facets on transverse processes.

Lumbar Vertebra Large, bulky centrum Large, bulky centrum Broad spinous processes Broad spinous processes No rib articulations No rib articulations Articular facets are sagittal Articular facets are sagittal Mamillary processes: Mamillary processes: On back rim of each superior articular process. Origins for multifidi.

Sacrum Consists of 5 fused vertebrae Consists of 5 fused vertebrae Wing-like processes of each vertebra= Wing-like processes of each vertebra=Alae For attachment to ilium Lip of body of first sacral vertebra = Lip of body of first sacral vertebra = Sacral promontory

Sacrum Posterior crests: Posterior crests: Median crest: Fused spinous processes Intermediate crests: Fused articular (zygopophyseal) processes Lateral crests: Fused transverse processes Sacral hiatus Sacral hiatus