LordosisLordosis is historically defined as an abnormal inward curvature of the lumbar spine. However, the terms lordosis and lordotic are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to abnormal convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed kyphosis or kyphotic. The term comes from the Greek lordōsis, from lordos ("bent backward").
Cervical vertebraeIn tetrapods, cervical vertebrae (: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In sauropsid species, the cervical vertebrae bear cervical ribs. In lizards and saurischian dinosaurs, the cervical ribs are large; in birds, they are small and completely fused to the vertebrae. The vertebral transverse processes of mammals are homologous to the cervical ribs of other amniotes.
SpondylolisthesisSpondylolisthesis is the displacement of one spinal vertebra compared to another. While some medical dictionaries define spondylolisthesis specifically as the forward or anterior displacement of a vertebra over the vertebra inferior to it (or the sacrum), it is often defined in medical textbooks as displacement in any direction. Spondylolisthesis is graded based upon the degree of slippage of one vertebral body relative to the subsequent adjacent vertebral body.
PremaxillaThe premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or os premaxillare, intermaxillary bone or os intermaxillare, and Goethe's bone.
Spinal fusionSpinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae. This procedure can be performed at any level in the spine (cervical, thoracic, lumbar, or sacral) and prevents any movement between the fused vertebrae. There are many types of spinal fusion and each technique involves using bone grafting—either from the patient (autograft), donor (allograft), or artificial bone substitutes—to help the bones heal together.
Anterior longitudinal ligamentThe anterior longitudinal ligament is a ligament that extends across the anterior/ventral aspect of the vertebral bodies and intervertebral discs the spine. It may be partially cut to treat certain abnormal curvatures in the vertebral column, such as kyphosis. The anterior longitudinal ligament extends superoinferiorly between the basiocciput of the skull and the anterior tubercle of the atlas (cervical certebra C1) superiorly, and the superior part of the sacrum inferiorly; inferiorly, it ends at the sacral promontory.
Vertebral columnThe vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordates has been replaced by a segmented series of bone: vertebrae separated by intervertebral discs. Individual vertebrae are named according to their region and position, and can be used as anatomical landmarks in order to guide procedures such as lumbar punctures.
Erector spinae musclesThe erector spinae (ɪˈrɛktər_ˈspaɪni ) or spinal erectors is a set of muscles that straighten and rotate the back. The spinal erectors work together with the glutes (gluteus maximus, gluteus medius and gluteus minimus) to maintain stable posture standing or sitting. The erector spinae is not just one muscle, but a group of muscles and tendons which run more or less the length of the spine on the left and the right, from the sacrum, or sacral region, and hips to the base of the skull.
Nuchal ligamentThe nuchal ligament is a ligament at the back of the neck that is continuous with the supraspinous ligament. The nuchal ligament extends from the external occipital protuberance on the skull and median nuchal line to the spinous process of the seventh cervical vertebra in the lower part of the neck. From the anterior border of the nuchal ligament, a fibrous lamina is given off. This is attached to the posterior tubercle of the atlas, and to the spinous processes of the cervical vertebrae, and forms a septum between the muscles on either side of the neck.
SpondylolysisSpondylolysis is a defect or stress fracture in the pars interarticularis of the vertebral arch. The vast majority of cases occur in the lower lumbar vertebrae (L5), but spondylolysis may also occur in the cervical vertebrae. In majority of cases, spondylolysis presents asymptomatically, which can make diagnosis both difficult and incidental.