Cervical Spine
Transcript: suprascapular nerve Cervical Spine There are six cervical discs, because there is no disc between the upper two joints. The first disc is between the axis (C2) and C3. From this level downwards to the C7–T1 joint they link together and separate the vertebral bodies. Each is named after the vertebra that lies above: e.g. the C4 disc is the disc between the C4 and C5 vertebrae. Intervertebral discs lie between adjacent vertebrae in the spine. Each disc forms a cartilaginous joint to allow slight movement of the vertebrae, and acts as a ligament to hold the vertebrae together. Ligaments of the lower cervical spine The lesser occipital nerve zygapophysial joint or facet joint arises from the upper trunk (formed by the union of the fifth and sixth cervical nerves). It innervates the supraspinatus and infraspinatus muscles. Lower cervical spine A.Movements: flexion, extension, and lateral bending B.Bones: condyles of occipital bone and superior facets of atlas c.Ligaments and membranes : 1.Anterior atlanto-occipital membrane: membrane between the foramen magnum and the anterior arch of the atlas 2.Posterior atlanto-occipital membrane: membrane between the margin of the foramen magnum and posterior arch of the atlas 3.Lateral atlanto-occipital ligament: connects transverse processes of the atlas to jugular processes of the occipital bone The great auricular nerve forms the joint connecting the skull and spine. The atlas and axis are specialized to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head.The atlanto-occipital joint allows the head to nod up and down on the vertebral column. The dens acts as a pivot that allows the atlas and attached head to rotate on the axis, side to side The anterior longitudinal ligament is closely attached to the vertebral bodies, but not to the discs. By contrast the posterior longitudinal ligament is firmly attached to the disc and is wider in the upper cervical spine than in the lower. Both ligaments are very strong stabilizers of the intervertebral joints. The lateral and posterior bony elements are connected by the ligamentum flavum, the intertransverse ligaments and interspinous ligaments and the supraspinous ligament or small occipital nerve is a cutaneous spinal nerve arising between the second and third cervical vertebrae, along with the greater occipital nerve. It innervates the scalp in the lateral area of the head posterior to the ear. The atlas and Axis second ligamentous complex connects the axis to the occiput: The cervical spine has seven vertebrae, which may be divided into two groups .The upper pair (C1 and C2, the atlas and axis) and the lower five (C3–C7) Anterior vertebral muscle Atlantoaxial Joint Atlanto-Occipital Joint Z-joint, or facet joint is a synovial joint between the superior articular process of one vertebra and the inferior articular process of the vertebra directly above it. The biomechanical function of each pair of facet joints is to guide and limit movement of the spinal motion segment. The lower cervical spine is composed of the third to the seventh vertebrae which are all very similar. The anteroinferior border of the vertebral body projects over the anterosuperior border of the lower vertebra. Intervertebral disc : Upper cervical spine muscles of posterior cervical B.Movement: rotation C.Bones: dens of axis articulates with the anterior arch of the atlas D.Ligaments 1.Anterior atlantoaxial ligament: from the body of the axis to the border of the anterior arch of the atlas 2.Posterior atlantoaxial ligament: from the lamina of the axis to the posterior arch of the atlas 3.Transverse ligament: spans across the arch of the atlas to hold dens against the anterior arch of the atlas originates from the cervical plexus, composed of branches of spinal nerves C2 and C3. It provides sensory innervation for the skin over parotid gland and mastoid process, and both surfaces of the outer ear Latral vertebral muscle