Vertebra - Definition of Vertebra

A spinal bone.

One of twenty-four ring-shaped bones which link together to form the backbone.

Referring to the vertebrae.

One of two arteries which go up the back of the neck into the brain.

Vertebrae, any of the 33 bones of the spinal column (vertebral column, or backbone), including 7 cervical (neck region), 12 thoracic (chest region), 5 lumbar, 5 sacral (fused), and 4 coccygeal (fused). Except for the first two—the atlas and axis— each vertebra consists of a centrum, or body, a neural arch enclosing a cavity through which the spinal cord passes, and processes for the attachment of muscles. The vertebrae are connected by ligaments and separated by intervertebral discs, which cushion adjacent vertebrae.

One of the ring-like bones that make up the spine. A cushion of fibrous cartilage with a gelatinous center (called a disk) lies between each vertebra except the first two below the skull and the last two, the sacrum and coccyx (tailbone). The disks allow each vertebra to move as a unit, giving the spine some flexibility.

One of the 33 bones of which the backbone is composed. Each vertebra typically consists of a body, or centrum, from the back of which arises an arch of bone (the neural arch) enclosing a cavity (the vertebral canal, or foramen) through which the spinal cord passes. The neural arch bears one spinous process and two transverse processes, providing anchorage for muscles, and four articular processes, with which adjacent vertebrae articulate. Individual vertebrae are bound together by ligaments and intervertebral disks.

One of the irregularly shaped bones that together form the vertebral column.

Any of the 33 bony segments of the spinal column: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal vertebrae. In adults, the five sacral vertebrae fuse to form a single bone, the sacrum, and the four rudimentary coccygeal vertebrae fuse to form the coccyx.

Any of the approximately 33 cylindrical bones composing the spinal column. Within the spine, there are seven vertebrae in the cervical region, twelve in the thoracic region, five in the lumbar region, five fused ones in the sacrum, and four fused ones in the coccyx. The upper 24 vertebrae are divided by cartilage discs. Each vertebra encompasses a central opening for the passage of the spinal cord and protrusions to which muscles are affixed.

Each of the 33 bones that make up the spinal column includes seven cervical vertebrae in the neck area, twelve thoracic vertebrae in the chest region, five lumbar vertebrae in the lower back, five sacral vertebrae that are joined to create the sacrum at the back of the pelvis, and four coccygeal vertebrae that merge to form the coccyx, a remnant of a tail in humans. A standard vertebra features a central body and an arch, which is constructed from two pedicles and two laminae. This arch is the foundation for seven projections—four for articulation, two transverse, and one spinous process.