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Spinal Anatomy

Spinal Anatomy Terms and Definitions

The front portion of the body. Often used to indicate a structure’s position in relation to another structure.
The fusion of bones across a joint, resulting in limited movement. It may occur spontaneously or result from a surgical procedure, such as spinal fusion.
Any disease or disorder of the joint.
The topmost vertebra (C1). Named after Atlas of Greek mythology, the atlas vertebra supports the head and forms the joint between the skull and the spine.
The second cervical vertebra (C2). With the atlas vertebra (C1), it forms the atlanto-axial joint, which allows the head to turn.
The solid central part of the vertebrae to which the arches and processes are attached.
Cervical Spine
The neck region of the spine containing the first seven vertebrae, referred to as C1, C2, C3, C4 & C5
The region of the spine below the sacrum. It is the triangular bone commonly called the tailbone.
Disc (Intervertebral)
The tough, elastic structure between the bodies of spinal vertebrae. Each intervertebral disc forms a fibrocartilaginous joint to allow slight movement of the vertebrae, acts as a ligament to hold vertebrae together, and serves as a shock absorber for the spine.
Positioned away from the center of the body.
A posterior structure of a vertebra that articulates with a facet of another vertebra to form a facet joint, allowing motion in the spinal column. Each vertebra has two superior and two inferior facets.
A natural opening or passage in bone.
Iliac Bone
The part of the pelvic bone situated above the hip joint. Autogenous bone grafts are frequently obtained from iliac bone.
Iliac Crest
The large, superior portion of the ilium, or pelvic bone, that forms the hip bone.
The uppermost and largest part of the hip bone. Divisible into two parts – the body and the wing.
Situated below or directed downward.
Intervertebral Foramen
A foramen between two spinal vertebrae. Cervical, thoracic, and lumbar vertebrae all have intervertebral foramina
The junction or articulation of two or more bones that allows movement between the bones.
Plates of bone that form the posterior walls of each vertebra, enclosing the spinal cord. Each vertebrae has two laminae.
Positioned away from the midline of the body.
A band of flexible, fibrous connective tissue that is attached at the end of a bone near a joint. Ligaments attach bones to one another, provide stability of a joint, and prevent or limit some joint motion.
The lower part of the spine between the thoracic region and the sacrum. The lumbar spine consists of five vertebrae, referred to as L1, L2, L3, L4 & L5.
Situated toward the midline of the body.
Nerve Root
The bony arch that surrounds the spinal cord on the posterior aspect of a vertebra. Also referred to as the vertebral arch.
Nucleus Pulposus
The semi–gelatinous tissue in the center of an intervertebral disc. It is surrounded and contained by the annulus fibrosus which prevents this material from protruding outside the disc space.
The thick process that extend from each side of vertebral body to help form the neural arch. Each vertebra has two pedicles that connect the lamina with the vertebral body.
A fibrous membrane covering the surface of all bones except at the joints of long bones. For children, periosteum is involved in forming new bone and molding the shape of bone. In adults, periosteum forms new bone following injury or infection.
Positioned or situated behind a structure, i.e., relating to the back side of the human body.
An artificial body part. Also used to describe some of the implants used in the body as replacement devices.
Nearest the midline of the body.
A part of the spine that is also part of the pelvis. It consists of five fused vertebrae that have no intervertebral discs. The sacrum articulates with the ilia at the sacroiliac joints and articulates with the lumbar spine at the lumbosacral joint.
Spinal Disc
See Disc (Intervertebral)
Spinal Column
See Spine.
Spinal Canal
The bony channel formed by the intravertebral foramen, contains the spinal cord and nerve roots.
Spinal Cord
The longitudinal cord of nerve tissue enclosed in the spinal canal. It serves as a pathway for nervous impulses to and from the brain, and as a center for carrying out and coordinating many reflex actions independently of the brain.
The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 vertebrae. The first 24 vertebrae are separated by intervertebral discs and held together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and 4 vertebrae are fused together to form the coccyx. The spine is also referred to as the vertebral column, spinal column, or backbone.
Situated above or directed upward toward the head.
A fibrous band of tissue composed mainly of collagen that connects muscle to bone.
The region of the spine that is located between the cervical and lumbar vertebrae, i.e., the chest and mid-back area. It consists of 12 vertebrae that serve as attachment points for the ribs.
Each of the 33 small bones forming the spinal column. A cervical, thoracic, or lumbar vertebra has a cylindrically–shaped body anteriorly and a neural arch posteriorly that protects the spinal cord. The plural of vertebra is vertebrae.
Vertebral End–Plates
The superior and inferior plates of cortical bone of the vertebral body adjacent to the intervertebral disc.
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