The Vertebral Column

The Vertebral Column Atypical Vertebrae Atypical Cervical Vertebrae Atlas (C1) • Articulates with the occiput of the head and axis C2. • The anterior arch contains a facet for articulation with the dens of the axis. - This is secured by the transverse ligament of the atlas which attaches to the lateral masses. • The posterior arch has a groove for the vertebral artery and C1 spinal nerve Axis (C2) • Contains superior articular facets. - Articulate with the inferior articular facets of the atlas to form the two lateral atlanto-axial joints Vertebrae Prominens (C7) • Articulates with a rudimentary cervical rib Atypical Feature • No vertebral body • No spinous process • Lateral masses which are connected by an anterior and posterior arch - Each lateral mass contains superior articular facet ✓ This is for articulation with the occipital condyles - Each also contain an inferior articular facet ✓ This is for articulation with C2 • • Easily identifiable due to its dens (odontoid process) - These extend superiorly from the anterior portion of the vertebra The dens articulate with the anterior arch of the atlas - This creates the medial alanto-axial joint ✓ This allows for rotation of the head independently of the torso Typical cervical vertebrae • C3-C6 Thoracic vertebrae • T1-T12 Lumbar Vertebrae • L1-L5 Sacrum Features on a vertebra. • • • Body Vertebral arch - Pedicles ✓ Forms the vertebral notches ✓ Vertebral notches of adjacent form the intervertebral foramina, through which the spinal nerves travel - Laminae Articular surfaces - Intervertebral disc - Zygapophyseal or facet joints - With ribs (thoracic vertebra) costal facets Comparison and contrasting vertebrae. Thoracic Vertebra Upper Thoracic Middle Thoracic Lower Thoracic Lumbar Vertebra Upper Lumbar Lower Lumbar Protects the spinal cord in their vertebral arches Provide a bony enclosure for the cauda equina nerves that descend from the spinal cord Deduce from the articular facets the movements of different regions of the spine Movements of the spine - Identify the movements produced at the following joints and regions Atlantooccipital joint • • Lateral masses of atlas that articulate with occipital condyles Flexion/extension and limited lateral bending and rotation Atlantoaxial joint Cervical spine Thoracic spine Lumbar spine • • • • • • Rotation of the head Flexion/extension: facilitated by position of zygapophyseal joints Lateral flexion: facilitated by large intervertebral disk Most stable region of the spine due to the ribs Rotation permitted around zygaphyseal joints Flexion/extension and lateral rotation both facilitated by curved and interlocking zygapophyseal joints Identify the bony attachments of the following major ligaments. - NOTE: THESE LIGAMENTS MAINTAIN JOINT STABILITY WHILE ALLOWING FOR MOVEMENT Of? Vertebral bodies Ligament Intervertebral discs Vertebral bodies Anterior and posterior longitudinal ligaments IMPORTANT NOTE: THE POSTERIOR LONGITUDINAL LIAGMENT IS NARROW AT THE BODY AND WIDER AT THE DISC Vertebral arches Ligament flava IMPORTANT NOTE: THICK, FIBREOELASTIC YELLOW CONNECTIVE TISSUE Interspinous and supraspinous ligaments Vertebral arches Bony attachments • Superiorly to the occipital bone • Anteriorly to the foramen magnum • Anteriorly to the tubercle of vertebra C1 (atlas) • Extends caudally to the anterior (pelvic) surface of the upper sacrum ANTERIOR • Vertebral bodies • Intervertebral discs along its length from the body of C2 (axis) POSTRIOR • Attached to the vertebral bodies • Mainly the intervertebral discs along its length from the body of C2 (axis) to the sacrum • From the superior attachment, the posterior longitudinal ligament extends into the intracranial aspect of the base of the skull as the tectorial membrane. • • Connects laminae of adjacent vertebral arches o each side Runs almost vertically from the anterior surface of the lamina above to the posterior surface of the lamina below INTERSPINOUS LIGAMENT • Connect adjacent vertebral spinous processes • Attaches from the base of the apex of ach spinous process. SUPRASPINOUS LIGAMENT • Hold the vertebrae together. ANTERIOR • Only ligament that prevents hyperextension of the spine POSTERIOR • Resists hyperflexion of the vertebral column and helps prevent posterior herniation of the nucleus pulposus of an IV disc • • Resist separation of the lamina during flexion Aids in the extension of the vertebral column back to its erect anatomical posture INTERSPINOUS LIGAMENT • Limits flexion of the spine SUPRASPINOUS LIGAMENT • Prevents separation of spinous processes during flexion and resists hyperflexion • Atlas and axis Atlantooccipital ligaments • Atlas and axis Atlantoaxial ligaments • Connects the tips of the spinous process from vertebra C7 to the sacrum Between the superior articular surfaces of the atlas and condyles of the occipital bones Superiorly on the posterior aspect of the lateral mass of the atlas near its transverse ligament • Flexion/extension • Rotation Boundaries of the intervertebral foramina • The particular spinal nerve which emerges from each intervertebral foramen • Where the vertebral vessel travel IMPORTANT NOTE: THE INTERVERTEBRAL DISC ANTERIROLY AND THE ZYGAPOPHYSEAL POSTERIROLY