Anatomy of the Spine #1 PDF

Functional Human Anatomy Spine #1 D R. D O N AL M U R R AY PH D C O N T R IBU T IO N S BY: D R. E LLE N C O S T E LLO, PT, P H D Session Objectives Identify bony landmarks on cervical, thoracic, lumbar, and sacral vertebrae Distinguish between cervical, thoracic, lumbar, sacral vertebrae Explain wh...

Functional Human Anatomy Spine #1 D R. D O N AL M U R R AY PH D C O N T R IBU T IO N S BY: D R. E LLE N C O S T E LLO, PT, P H D Session Objectives Identify bony landmarks on cervical, thoracic, lumbar, and sacral vertebrae Distinguish between cervical, thoracic, lumbar, sacral vertebrae Explain why different regions of the spine are able to move in different directions (e.g. rotation vs. flexion/extension vs. sidebending) Identify the ligamentous structures which support the spine Explain the structure and function of the intervertebral disc Explain what the implications are related to the spinal cord ending ~ LV1,2 Explain the type of fibers located in the cauda TV1 LV2 SV1 Vertebrae Body-function is support Vertebral arch-function is protective Vertebral foramen-houses spinal cord Intervertebral foramina-houses spinal nerves & vessels x Superior articulating process  i Vertebrae s Vertebral Arch composed of 2 lamina & 2 pedicles Vertebral notches -superior (s) and inferior (i) vertebral notches which form the intervertebral foramen 7 projections from the arch  2 transverse processes (t)  1 spinous process (s)  2 superior articulating processes (sap)  2 inferior articulating processes  together the articulating P processes make a small synovial t t sap L sap jt. (zygoapophyseal jt) s  Superior articulating process Intervertebral Foramen formed by: Inf vertebral notch above & Sup vertebral Facet joint notch below IAP  Cervical Vertebrae 7 cervical vertebrae Typical cervical vertebrae  small broad body  vertebral foramen-large & triangular  spinous process-short & bifid  sup aspect (body)-slightly concave x  inf aspect (body)-slightly convex  sup articulating process facing post & upwards at 45’  inf articulating facet facing forward and downward  Transverse foramen  transverse processes have foramen that transmit vertebral arteries, sympathetic nerves & venous plexus  Wider med-lat vs ant-post See the triangle See the holes See the prongs  cv2 Where is the facet joint (aka zygoapophyseal jt) CV2 Angle of facet joint: ~45’ from horizontal in cervical vertebrae Where is the x intervertebral foramen? TV1  Uncus (uncinate process) CV3-CV6 only What would be located here? vertebral arteries and accompanying venous and sympathetic plexuses pass through foramina transversarii of all cervical vertebrae except C7, which transmits only small accessory vertebral veins Cervical Vertebrae Movements Gross AROM (CV2-CV7)  flexion/extension-greatest; 105’ x x  followed by rotation; 45’ (unilat)  then sidebending; 35’(unilat) CV1-(atlas)  no body-occupied by dens of CV2  articulates with occiput  has no true spinous process  has lateral masses (see x)  movements-between occiput & atlas (O-A Jt.)  flexion/extension-15’ (5’flex/10’ ext)  sidebending-5’ (unilat)  rotation-0’  movement is primarily gliding or chin tuck  CV1: Sup Facet for dens view Sup artic surface of lateral mass CV2: ant view CV1: Inf view CV2: post view CV2-Axis Pivot upon which the atlas & head rotates Distinguished by the dens; held in place by alar lig & transverse ligament Has a body Transverse processes are small & bifid Movements between CV1 and CV2 (A-A jt) rotation-40-45’ ½ of cervical rotation occurs between CV1 and CV2 flexion/extension- 5’ flex/10’ ext sidebending-0’ rotation is greatest due to horizontally directed articular processes between CV1 and CV2 Ligamentous Support What is main difference about the thoracic vertebrae as compared to cervical vertebrae? Thoracic Vertebrae 12 in number-show a gradual increase in body size Have costal demifacets at the junction of the body & pedicles for articulation with heads of ribs Facets on transverse processes to articulate with tubercle of ribs Typical thoracic vertebrae transverse & A-P dimension of body almost equal costal demifacets (bilaterally): superiorly & inferiorly which articulate with head of rib vertebral foramen is relatively small & round spinous process slants down & posterior superior articulating facets face posteriorly at 60’ angle inferior articulating facet faces anteriorly transverse processes-club shaped with oval facets which articulate with tubercle of ribs  Gross AROM (CV2-CV7) Typical thoracic vertebrae - - Flexion/Extension greatest; 105’ Followed by rotation; 45; (unilat) transverse & A-P - Then Sidebending; 35’ (unilat) dimension almost equal Movements between CV1 and CV2 (A-A jt) - Rotation: 40-45’ two costal demifacets: - ½ of cervical rotation occurs between CV1 and CV2 superiorly & inferiorly - Flexion/extension: 5’ flex/10’ ext which articulate with head of rib vertebral foramen is relatively small & round spinous process slants x x down & posterior superior articulating facets face posteriorly at 60’ angle inferior articulating facet x x faces anteriorly transverse processes-club shaped with oval facets which articulate with tubercle of ribs  Sup costal facet Inf costal facet x x Facet jt: ~ 60’ off x horizontal Note: articular facet x for transverse process of vertebrae x x Note: Superior & Inferior articular facet for vertebral body Thoracic Vertebrae Cont. TV1-complete facet on sup aspect body for whole head rib 1 & demifacet inferiorly to articulate with rib 2 TV9-often no inf demifacet rib 10 TV10, 11, 12 -articulates with their own respective rib (10, 11, 12) Although ROM at each thoracic intervertebral joint is relatively small, cumulative motion is considerable for the 12 segments Thoracic Vertebrae cont. ROM  Flexion 30-40’; extension 20-25’  Rotation 30’ (unilat) Sidebending 25’ (unilat) Orientation of facets would favor SB movements however ribs restrict the motion Due to change in orientation of facets as you move lower in the thoracic spine; certain intervertebral motions will decrease. Costovertebral Joint Synovial jt Articulation between the head of rib with facets on body of vertebrae & with intervertebral disc in between Ligaments-radiate & intra- x articular Intra-articular ligament Intra-articular ligament Costotransverse Joint Synovial articulation between the tubercle of the rib & transverse process of the vertebrae Ligaments:  Costotransverse  superior & lateral costotransverse x Cut sup costo- transverse ligament Lumbar Vertebrae 5 in number Characterized by: greater body size, absence of costal facets, absence of transverse foramen Body wider laterally than A-P Spinous process almost horizontal; quadrangular shape x Superior articulating process face medially & post Inferior articulating process face laterally & ant  Facet joint Inf articulating process What is this? What is this? Lumbar Vertebrae cont. Facets are saddle like and oriented in a sagittal plane favoring flexion and extension Transverse processes thin & long LV5 distinguished by massive transverse process with large body & small spinous process Mamillary process-located on sup artic process; provides for attachment for multifidi ms Accessory processes-for muscle attachment Gross AROM Lumbar Region  50’ flex/ 15’ ext  20’ SB (unilat)  5’ Rotation (unilat) Facet joint Variations in vertebrae – Nice to know A. “Cranial shift” -13 ribs, including a cervical rib articulating with vertebra C7 and a diminished 12th rib articulating with vertebra T12. B. Common arrangement of vertebrae and position of 1st and 12th ribs. C. “Caudal shift.” 12th rib is increased in size, and there is a small lumbar rib. Ligamentous Support Contribute to the spine’s intrinsic stability High in collagen content, limits extensibility during motion Anterior Longitudinal Ligament (ALL)  unites vertebral bodies & IV discs  located ant surface of vertebral bodies; broader inferiorly than superiorly; thicker & narrower across vertebral bodies versus IV disc  attached superiorly to occiput & inferiorly to sacrum  function-resists trunk extension ALL Ligamentous Support cont. Posterior Longitudinal Ligament (PLL)  unites post aspect of vertebral bodies & IV discs  located inside the vertebral canal on post surface of vertebral bodies  attached sup to axis & inf to sacrum primarily to the intervertebral disc (rather than the bone)  lateral disc left unprotected; potential for postlat disc protrusion  Much weaker band than the ALL  function-limits FB slightly  Highly innervated with sensory nerve fibers x  PLL PLL deficient posterolaterally Ligamentous Support cont. Ligamentum Flavum  connects the lamina to lamina of vertebrae;  forms posterior wall of Lig flavum vertebral canal  composed of yellow elastic tissue  thickest in the lumbar region  function- resist separation of the vertebral lamina and restrain mobility of the facet jt. Ligamentum flavum lamina Interspinous Ligament Thin and weak; connects adjoining spines from root to apex limits FB; very elastic; has to stretch 2.5x its resting length root apex Note incorrect fiber orientation of interspinous ligament: D Heylings 1978 Intertransverse Ligament between transverse processes function-? limits SB or rotation Ligamentous Support cont. Supraspinous Ligament  Connects tips of spinous processes of CV7-sacrum  thicker & broader in lumbar region  most superficial layer of ligament; extends 3-4 spines  limits FB  Merges superiorly with the nuchal ligament (Ligamentum Nuchae) Ligamentum Nuchae  continuation of supraspinous & interspinous ligaments in C region  fibroelastic membrane that gives rise to ms attachment especially for CV3-CV5 (very short spinous x processes) Dentate Ligament (aka Denticulate ligament) 20 pairs of ligaments Connective Tissue attaching the dura mater to the pia mater Arises from the spinal cord between the ventral & dorsal roots Function: holds the arachnoid x layer of meninges & spinal cord suspended within the dura CSF runs between the arachnoid & pia in subarachnoid space Recap Can you describe unique features of Cervical, Thoracic and Lumbar vertebrae and ribs? Can you visually ID vertebrae and determine if it is C, T, or L in nature? Can you explain what a facet joint (zygapophyseal jt) is and how it dictates motion in that region? Can you describe the costovertebral and costotransverse joints? What type of joints are they? Can you ID and describe the function of the ALL, PLL, ligamentum flavum, interspinous, supraspinous ligaments and small ligaments that support the ribs? Can you describe the function of the dentate ligament (aka denticulate ligament)?