Joint Anatomy PDF

JOINT INTERVERTEBRAL JOINTS JOINT 1 (ANTERIOR): vertebrae bodies articulate with body of upper and lower vertebra via intervertebral disc JOINT 2 (POSTERIOR): articular processes of each vertebra articulate with upper and lower vertebrae articular processes Synovial planar joints called zygapophysi...

JOINT INTERVERTEBRAL JOINTS JOINT 1 (ANTERIOR): vertebrae bodies articulate with body of upper and lower vertebra via intervertebral disc JOINT 2 (POSTERIOR): articular processes of each vertebra articulate with upper and lower vertebrae articular processes Synovial planar joints called zygapophysial (facet joints) = belong to diarthrodial (synovial) variety = planar joints = slide and glide SURFACES Intervertebral disc: a fibrocartilaginous structure that intervenes between the bodies of the adjacent vertebrae and binds them together (20-25% of vertebral column length) 1. Nucleus pulposus: fills central part of disc and is gelatinous which absorbs compression forces between vertebrae 2. Annulus fibrosus: made of collagen fibres forming peripheral part of the disc *degenerative changes in anulus fibrosus can lead to herniation of nucleus pulposus *postero-lateral herniation can impinge on roots of a spinal nerve in the intervertebral foramen WHAT IT DOES Functionally amphiarthoridal joints (slightly moveable) and structurally cartilaginous symphysis joints Permits overall spine motion; slide and glide WHO REINFORCES IT Anterior Longitudinal Ligament (ALL): extending along the anterior surfaces of the bodies of the vertebrae, from occipital bone to the sacrum - Limits backward bending (prevent hyperextension) - Supports anterior convexity in the lumbosacral area Posterior Longitudinal Ligament (PLL): sits in vertebral canal, extends along posterior surfaces of the vertebrae bodies from body of axis to sacrum - Does not attach to the body but covers a plexus of arteries, veins and lymphatics and the nutrient foramina through which these vessels pass to the cancellous bone of the body - Low tensile strength and does not significantly restrict forward bending (no protection of backside of joint) Ligament flavum: connects lamina to lamina (posterior) from C2àS1 - Helps to resume upright posture after flexion and supports facet joints Supraspinous ligament: connects spinous process to spinous process - Extends from sacrum to C7 - From C7 – occipital bone supraspinous ligament becomes nuchal ligament Interspinous ligament: thin membrane extending from extending from spinous process apex to root - Fills gap between spinous process to spinous process Intertransverse ligament: connect between the TVP’s Nuchal ligament: fibrous membrane in the neck representing the supraspinous ligaments of lower vertebrae - Runs from occipital protuberance to SP of C7 - Gives neck mobility against gravity and connects vertebral column with cranium CRANIOVERTEBRAL JOINTS ATLANTOAXIAL JOINT (2 lateral + one median): between C1+C2 vertebrae; similar to facets = slide and glide individually, made up of facet surfaces and add overall mobility to spine - Difference = portion of the atlas permitting the joint is lateral mass LATERAL ATLANTOAXIAL JOINT (2) Synovial gliding joint between lateral masses of atlas and the superior articular processes of the axis MEDIAL ATLANTOAXIAL JOINT Synovial pivot joint between odontoid (BETWEEN DENS AND ANTERIOR process of the axis and the ring formed by ARCH OF C1) the anterior arch and the transverse ligament of the atlas Enables rotation of the atlas (with the skull) upon the axis - Vertical axis of motion through the dens - 50% rotation of cervical spine Anterior Atlantoaxial Ligament (membrane): strong fixed membrane, runs from anterior arch of atlas down below to body of axis Posterior Atlantoaxial Ligament (membrane): broad thin membrane, instead of ligamatum flavum because atlas doesn’t have lamina the PAL attaches the posterior arch of the atlas below to the laminae of axis Cruciate ligament of the atlas (cross structure); superior longitudinal band, transverse ligament of atlas, inferior longitudinal band: - TLofA wraps around posterior aspect of dens and anchors dens to anterior arch of atlas (one side of anterior arch to the other side) anchoring it to the lateral ATLANTOOCCIPITAL JOINT Where atlas forms a connection with occipital bone Permits biaxial movements – flexion and extension (forward and backward nodding of the head) Slight-lateral flexion (bending) and head rotation UNCOVERTEBRAL JOINT: Synovial planar joints formed between uncinate processes of the cervical vertebrae Located in cervical vertebrae between C3 and C7 Enable flexion and extension Limit lateral flexion in the cervical spine mass (formed on anterior side of atlas) - SLB attached to basilar part of occipital bone and connects to TLofA - ILB attached from posterior side of body of axis onto the TLofA Articular capsules: surround condyles of occipital bone and connect with superior articular surfaces of lateral masses of atlas (thin and loose) Anterior Atlantooccipital membrane: attaches from anterior arch axis to skull Posterior Atlantooccipital membrane: posterior arch of atlas to occiput bone Tectorial membrane: continuation of PLL, runs posteriorly of the dens to secure placement and runs up all the way to the skull **Runs over crucial ligament** Alar ligaments: on either side of upper part of dens and pass obliquely (upward and lateral) until they insert on medial sides of condyles of occipital bone Two lips project upward from the superior surface of vertebral body below One lip projects downward from inferior surface of vertebral body above RIB JOINTS: - Give rise to superior and lateral movement of ribs during inhalation - Give rise to inferior and medial movement of ribs during exhalation - Posterior joints of the thoracic cage: EACH RIB TOUCHES 2 VERTEBRAL BODIES + 1 TVP (Ex: 7th rib forms articulation with bodies of T7 and T6 and the TVP of T7) - T1, T10, T11, T12 only articulate with rib 1, 10, 11, 12 at their vertebral bodies COSTOVERTEBRAL JOINT: between thoracic vertebrae and rib Formed by articulation of head of typical ribs (3-9) with facets on the sides of the bodies of the thoracic vertebrae and with intervertebral discs between them 1st, 10th, 11th, 12th ribs each articulate with a single vertebrae COTRANSVERSE JOINT: formed between tubercle of the rib with articular surface on the adjacent transverse process (diarthrodial joint) STERNOCOSTAL (permit mobility) AND COSTOCHONDROL (permit flexibility) JOINTS: synovial planar joints that attach the sternum (sterno-) with the costal cartilages (-chondral) of the thorax Articulations of head of ribs give rise to a series of synovial planar (gliding) joints (diarthrodial joints) Adds to overall mobility of thoracic rib cage True ribs (2-7) form sternocostal joints and are synovial = offer a little bit of mobility Rib 1 = no synovial joint = instead 2 bones connected by hyaline cartilage to form a synchondrosis articulation Slight gliding movements are permitted in the sternocostal joints Costochondral articulations – lateral end of each costal cartilage is received into a depression in sternal end of rib, and they are held together by the PERIOSTEUM (where rib meets cartilage) - They are synchondrosis joints (structurally synarthrosis) Radiate ligament of head of rib: connects anterior part of head of each rib with side of the bodies of two vertebrae, and intervertebral disc between them Intra-riticular ligament of head of rib: in the joints interior, anchoring rib to stay on the disc - Attaches on head of rib and runs into intervertebral disc - Divides joint into two cavities Superior Costotransverse ligament: holds rib up - Attached to upper border of neck of rib and transpose process directly above Costotransverse ligament: fills the gap - Connects rough surface on back of rib neck with anterior surface of adjacent TVP Lateral Costotransverse ligament: reinforces posterior aspect - Passes obliquely from tip of TVP to rough non-articular tubercle of rib Anterior and Posterior Radiate Sternocostal Ligaments: broad and thin membranous bands radiating from front and back of sternal ends of cartilages of true ribs to anterior and posterior surfaces of sternum