Ernest F. Talarico, Jr., Ph.D., M.S., B.S., C.L.A. Assistant Director of Medical Education Assistant Professor of Anatomy & Cell Biology Course Director, Human Gross Anatomy & Embryology Indiana University School of Medicine - Northwest Gary, Indiana

1.Understand the gross anatomy of the spine and vertebrae (regions, curvatures, ligaments and bony structures) 2.Understand the anatomy and histology of the intervertebral disc. 3.Discuss the spinal nerve. 4.Brief introduction to spinal pathology.

IUSM-NW Vertebral Column (Spine)  33 vertebrae 7 cervical (C) 12 thoracic (T) 5 lumbar (L) 5 sacral (S) 4 coccygeal (C 0 ) cervical thoracic lumbar sacral coccygeal Intervertebral disc primary curvatures = thoracic and sacral (born with) secondary curvatures = cervical (infant holds head upright) and lumbar (upright posture)

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IUSM-NW Structure of a Typical Vertebra

IUSM-NW lumbarthoracic

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IUSM-NW Vertebrae (vertebra = singular) cervicalsacral (sacrum) thoracic lumbarcoccygeal Looking at “real” bone.

IUSM-NW cervical atlas (C1) Axis (C2) skull C1 C2

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IUSM-NW Diagram of human lumbar intervertebral disc and dissection of cylindrical-shaped specimens of annulus fibrosus. Axial and radial correspond to orientations parallel and perpendicular to the vertebral body line of the spine, respectively. Annulus layers are roughly mm thick with approximately 40 fiber bundles per layer alternating at roughly +/- 30 degrees. nucleus pulposus (NP) Intervertebral Disc

IUSM-NW disc annulus fibrosus nucleus pulposus Looking at a human cadaver.

IUSM-NW FIBROCARTILAGE (INTERVERTEBRAL DISC) Stained with haematoxylin and eosin 1 - cells of the cartilage (chondrocytes, chondroblasts) 2 - intercellular cartilage matrix 3 - nucleus pulposus 4 - annulus fibrosus ` Disc Histology

IUSM-NW anterior longitudinal ligament intertransverse ligaments discs

IUSM-NW anterior longitudinal ligament intertransverse ligaments anterior intertransverse muscles

IUSM-NW supraspinous ligaments anterior intertransverse muscles posterior intertransverse muscles rotatores thoracis muscles multifidus muscle

IUSM-NW Looking inside the vertebral column. posterior longitudinal ligament disc vertebral venous plexus vertebrae

IUSM-NW posterior longitudinal ligament anterior longitudinal ligament Looking at a human cadaver.

How to treat back pain.

IUSM-NW aorta disc DRG spinal nerve

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IUSM-NW Spinal Cord Looking at a “real” spinal cord and the spinal nerves.

IUSM-NW Spinal Nerves (31 pairs)  all are mixed nerves (sensory and motor)  4 fiber components Sensory –GSA: general somatic afferent –GVA: general visceral afferent Motor –GSE: skeletal –GVE: visceral

IUSM-NW Typical Thoracic Spinal Nerve 31 pairs of spinal nerves: 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

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IUSM-NW Photograph of normal (left) and degenerative human L2-3 intervertebral discs. Disc Pathology Degenerative disc disease (DDD) is caused by the damage or dehydration of the nucleus pulposus, which reduces the hydrostatic pressure on the internal surface of the annulus fibrosis. This results in abnormal compressive stress on the intervertebral disc, causing tears, cracks and fissures in the annular tissues after repeated loads. This can manifest in back pain as the result of the nucleus migrating through the annulus and impinging on nerve roots.

IUSM-NW  Degenerative disc disease (DDD) of the lumbar spine is a relatively common condition in aging adults.  Our intervertebral discs serve as shock absorbers for the spine, and as we age they gradually dry out, losing strength and resiliency. These changes are gradual in most people. In fact, many of our patients don’t know they have degenerative disc disease. They only become aware of the condition when being examined for another health problem.

IUSM-NW A b C d Spectrum of disc disease in a single patient. A. Sagittal MRI T2-weighted. B-D. Axial proton-density images. MRI accurately depicts disc, vertebral marrow, and thecal sac contents. In this patient, L3-4 shows normal disc signal and morphology (B). At L4-5, there is annular bulging (C) and at L5-S1 a central disc protrusion is present (D). L3 L4 L5 S1 L3 - 4 L4 - 5 L5 - S1