Axial skeleton: vertebrae and bony thorax Claudia Stanescu, Ph.D. Office Hours in Gittings 108 Tue 10-11am and Thurs 1-2pm or by appointmentObjectives: 1. List and describe the features common to all vertebrae. 2. Distinguish between the three different types of vertebrae (cervical, thoracic, and lumbar). 3. Name the components of the thoracic cage. 4. Describe the articulations of the sternum with the clavicle and with the ribs.Objectives: 5. Differentiate between the true and false (including floating) ribs. 6. Describe the articulations of the ribs with the vertebrae including how these articulations differ between T1, T2-T8, T10, T11, and T12.Vertebral column is made up of 26 bones: 7 cervical 12 thoracic 5 lumbar 1 sacrum 1 coccyx4 normal curvatures of the vertebral column: Primary: 1)Thoracic 2)Sacral Secondary: 1)Cervical 2)LumbarSingle curve in fetus Four curves in adult 1 2 3 4 4 normal curvatures of the vertebral column: Primary: 1)Thoracic 2)Sacral Secondary: 1)Cervical 2)LumbarFeatures of a Typical Vertebra (superior view) ANTERIOR POSTERIOR Facet of superior articular process Spinal cord Spinous process Vertebral foramen Facet for head of rib Transverse process Lamina Pedicle Vertebral bodyFeatures of a Typical Vertebra (posterolateral v.) POSTERIOR ANTERIOR Transverse process Vertebral body Spinal cord Facet of superior articular process Spinal nerve Facet for head of rib Intervertebral foramen Intervertebral disc Inferior articular process Spinous processHerniated Disc (superior view) Spinal cord POSTERIOR ANTERIOR Spinous process of vertebra Herniated disc Spinal nerve Annulus fibrosus Nucleus pulposus Spinal nerve compression(no vertebral body - largerLamina Vertebral foramen Transverse process Transverse foramen Bifid spinous process Superior articular facet Pedicle Vertebral body POSTERIOR ANTERIOR Typical Cervical Vertebra (superior view)C1 (The Atlas) (superior view) POSTERIOR Posterior arch ANTERIOR Superior articular facet Articular surface for dens of axis Anterior arch Vertebral foramen Transverse process Transverse foramen (no body)(helps with “yes” movement)(occipital bonearticulares)(axis articulates)underneathC2 (The Axis) (superior view) POSTERIOR ANTERIOR Vertebral foramen Superior articular facet Spinous process Inferior articular process Dens Lamina Transverse process Vertebral body (rotation for “no” movement)(where atlas articulates)Thoracic Vertebra (right lateral view) POSTERIOR ANTERIOR Superior articular facet Pedicle Transverse process Facet for articular part of tubercle of rib Inferior articular facet Spinous process Superior demifacet Vertebral body Inferior demifacet (articulate with ribs) (spinous process - downward and sharp/giraffe)(not as sharp)(sharpest)(more like lumbar)Lumbar Vertebra (right lateral view) POSTERIOR ANTERIOR Superior articular process Transverse process Spinous process Inferior articular facet Superior vertebral notch Pedicle Vertebral body (square, blunt - large body to support weight)(no rib articulation with lumbar or cervical)Classification of vertebrae Important features used to identify vertebrae • Cervical – transverse foramina and bifurcated (bifid) spinous process • Thoracic – sharp inferiorly pointed spinous process • Lumbar – blunt posteriorly pointed spinous process Cervical vertebra Thoracic vertebra Lumbar Vertebra (transverse foramena)Structure and function of the vertebrae Cervical vertebrae – Transverse foramina house blood vessels and nerves – Large vertebral foramen for cervical enlargement of the spinal cord Thoracic vertebrae – Facets for rib articulation Lumbar vertebrae – Largest body because they bear most of the weight of the upper body TextSacrum and Coccyx (posterior view) Sacral canal Auricular surface Posterior sacral foramen Median sacral crest Superior articular facet Sacrum Coccyx Co1 Co2 Co3 Co4 (part of vertebral colum)(for nerves)(continuous with spinal processes)(look like ears) (where coxal bone articulation)(sacrum articulates withL5, coxal bone, coccyx)Sacrum and Coccyx (anterior view) Base of sacrum Anterior sacral foramen Superior articular process Sacrum Apex of sacrum Co1 Co2 Co3 Co4 Coccyx S1 S2 S3 S4 S5 (five vertebrae fussed together) (three-five vertebrae fussed) (for nerves)INFERIOR SUPERIOR Suprasternal notch STERNUM: Manubrium Body Xiphoid process Clavicle Clavicular notch Scapula Costal cartilage Intercostal space 1 2 3 4 5 6 7 8 9 10 T9 T10 T11 T12 11 12 The Bony Thorax (anterior view) (top)(middle)(bottom)(clavicle articulation)(rib cartilage)(in open heart surg.-cut through sternum-bone heals better thancartilage bc vasculature-cartilage avascular)-bone has blood vessels-cartilage does not rib 1-7 = true ribsrib 8-10 = falserib 11-12 = floating(true = own cartilagefalse = share cartilagefloating = no cartilage)Head Tubercle Articular facet Superior facet Inferior facet Facet for costal cartilage Rib (posterior view of left rib)Transverse process ANTERIOR POSTERIOR Facet for tubercle of rib Superior demifacet Vertebral body Head of rib Facet for transverse process Tubercle of rib Facet for tubercle of rib Spinous process View Rib Articulation (superior view of left rib articulation) (articulates to transverse process)(articulates to facet/demifacet)-tubercle only articulates with one vertebrae-head can articulate to 2 vertebraeFacet for articular part of tubercle of ribs 1-10 Superior facet for head of rib 1 Inferior demifacet for head of rib 2 Superior demifacet for head of rib 2-8 Inferior demifacet for head of rib 3-9 Superior demifacet for head of rib 9 Superior facet for head of rib 10 T1 T2–8 T9 T11 T12 T10 Thoracic Vertebrae Facet for head of rib 11 Facet for head of rib 12 No facets for tubercle of ribs 11 and 12Articulation between rib 1 and thoracic vertebra T1: 1) The head of the rib articulates with one thoracic vertebra • the facet on the body of T1 2) The tubercle of the rib 1 articulates with the transverse process of T1Articulation between ribs and thoracic vertebrae T2-T8: 1) The head of the rib articulates with two thoracic vertebrae • the inferior demifacet of the superior vertebra • the superior demifacet of the inferior vertebra 2) The tubercle of the rib articulates with the transverse process of the inferior vertebra • the facet on the transverse processArticulation between rib 9 and thoracic vertebra T9: 1) The head of the rib articulates with two thoracic vertebrae • the