Formation and branching pattern of a typical spinal nerve
Formation and branching pattern of a typical spinal nerve
Joints in the cervical, thoracic, and lumbar regions of the vertebral column. B. Third lumbar vertebra seen from above showing the relationship between intervertebral disc and cauda equina. C. Sagittal section through three lumbar vertebrae showing ligaments and intervertebral discs. Note the relationship between the emerging spinal nerve in an intervertebral foramen and the intervertebral disc.
C. Posterolateral herniation of the nucleus pulposus of the intervertebral disc between the fifth lumbar vertebra and the first sacral vertebra showing pressure on the S1 nerve root. D. An intervertebral disc that has herniated its nucleus pulposus posteriorly.
This is particularly liable to occur if the vertebral canal is abnormally narrowed, usually by osteoarthritic changes
Conceptual overviewConceptual overview FunctionsSupportMovement <additive>Protection of central & peri nervous systems flexion extension lateral flexion rotation, and circumduction
curvescurvesSec curvature bring the centerof gravity to a vertical line,which allows the body’s weightto be balanced on the vertebralcolumn in a way that expendsthe least amount of muscularenergy to maintain anupright bipedal stance.
LigamentsLigamentsSupraspinous This runs between the tips of adjacent spines.Interspinous : This connects adjacent spines.Intertransverse: These run between adjacent transverse processes.Ligamentum flavum : This connects the laminae of adjacent vertebrae.cervical region= supraspinous and interspinous ligaments greatlythickened to form the strong ligamentum nuchae.
Dislocations and fractures ofthe vertebral column.A. Unilateral dislocation of the fifth or thesixth cervical vertebra. Note the forwarddisplacement of the inferior articularprocess over the superior articular processof the vertebra below. B. Bilateraldislocation of the fifth or the sixthcervical vertebra. Note that 50% ofthe vertebral body width has movedforward on the vertebra below. C.Flexion compressionâ€“type fractureof the vertebral body in the lumbarregion. D. Jeffersons-typefracture of the atlas. E.Fractures of the odontoidprocess and the pedicles(hangmans fracture) of theaxis.
A. Arrangement of theA. Arrangement of thedeep muscles of thedeep muscles of theback. B. Lateral view ofback. B. Lateral view ofthe skeleton showingthe skeleton showingthe line of gravity.the line of gravity.Because the greater part of theBecause the greater part of thebody weight lies anterior tobody weight lies anterior tothe vertebral column, the deepthe vertebral column, the deepmuscles of the back aremuscles of the back areimportant in maintaining theimportant in maintaining thenormal postural curves of thenormal postural curves of thevertebral column in thevertebral column in thestanding position.standing position.
MusclesMusclesTrap, Lat dorsi, Lev scap, Rho maj & minSerratus posterior sup & inf DeepSuperficial Vertically Running MusclesIntermediate Oblique Running MusclesDeepest MusclesInterspinalesIntertransversarii
Muscular triangles of backMuscular triangles of backAuscultatory TriangleThe auscultatory triangle is the site on the back where breathsounds may be most easily heard with a stethoscope. Theboundaries are the latissimus dorsi, the trapezius, and the medialborder of the scapula.Lumbar TriangleThe lumbar triangle is the site where pus may emerge from theabdominal wall. The boundaries are the latissimus dorsi, theposterior border of the external oblique muscle of the abdomen,and the iliac crest.
Deep Fascia of the BackDeep Fascia of the Back(Thoracolumbar Fascia)(Thoracolumbar Fascia) The lumbar part of the deep fascia is situated in the interval betweenthe iliac crest and the 12th rib. It forms a strong aponeurosis andlaterally gives origin to the middle fibers of the transversus and theupper fibers of the internal oblique muscles of the abdominal wall Medially, the lumbar part of the deep fascia splits into three lamellae.The posterior lamella covers the deep muscles of the back and isattached to the lumbar spines. The middle lamella passes medially, tobe attached to the tips of the transverse processes of the lumbarvertebrae; it lies in front of the deep muscles of the back and behindthe quadratus lumborum. The anterior lamella passes medially and isattached to the anterior surface of the transverse processes of thelumbar vertebrae; it lies in front of the quadratus lumborum muscle.
Blood Supply of the BackBlood Supply of the Back Arteries◦ In the cervical region, branches arise from the occipital artery, a branchof the external carotid; from the vertebral artery, a branch of thesubclavian; and from the deep cervical artery, a branch of thecostocervical trunk.◦ In the thoracic region branches arise from the posterior intercostalarteries.◦ In the lumbar region branches arise from the subcostal and lumbararteries.◦ In the sacral region branches arise from the iliolumbar and lateral sacralarteries, branches of the internal iliac artery. Veins◦ The veins draining the structures of the back form plexuses extendingalong the vertebral column from the skull to the coccyx.◦ The external vertebral venous plexus lies external and surrounds thevertebral column.◦ The internal vertebral venous plexus lies within the vertebral canal butoutside the dura mater of the spinal cord.
Lymph Drainage of the BackLymph Drainage of the Back The deep lymph vessels follow the veins and drain into the deepcervical, posterior mediastinal, lateral aortic, and sacral nodes. The lymph vessels from the skin of the neck drain into thecervical nodes, from the trunk above the iliac crests drain into the axillarynodes, and those from below the level of the iliac crests drain into the superficialinguinal nodes
RelationRelationVertebrae Spinal SegmentCervical Add 1Upper thoracic Add 2Lower thoracic (T7 to 9) Add 3Tenth thoracic L1 and 2 cord segmentsEleventh thoracic L3 and 4 cord segmentsTwelfth thoracic L5 cord segmentFirst lumbar Sacral and coccygeal cord segment
Posterior views of vertebral bodies in thecervical and lumbar regions showing therelationship that might exist between theherniated nucleus pulposus and the spinalnerve roots. Note that there are eight cervicalspinal nerves but only seven cervicalvertebrae. In the lumbar region, for example,the emerging L4 nerve roots pass out laterallyclose to the pedicle of the fourth lumbarvertebra and are not related to theintervertebral disc between the fourth andfifth lumbar vertebrae. E. Pressure on the L5motor nerve root produces weakness ofdorsiflexion of the ankle; pressure on the S1motor nerve root produces weakness of plantarflexion of the ankle joint.
SPINAL CORD INJURY WITHOUT RADIOLOGICAL ABNORMALITY:‘SCIWORA’This is particularly liable to occur if the vertebral canal isabnormally narrowed, usually by osteoarthritic changes.