Vertebra

Vertebra_cervicalis

Spinal column curvature

The vertebra (plural: vertebrae) represents one of the 33 individual bones that collectively form the vertebral column, more commonly known as the spine or backbone. This bony column provides the main support for the body, allowing individuals to stand upright, bend, and twist. Additionally, the vertebrae encase and protect the spinal cord, a crucial component of the central nervous system.

Anatomy of a Vertebra

Each vertebra consists of several integral parts:

• Vertebral Body: This is the thick, cylindrical anterior section of the vertebra, and it bears the majority of an individual's weight.
• Vertebral Arch: Located posterior to the vertebral body, it forms a protective canal for the spinal cord.
• Spinous Process: This is the bony projection off the posterior (back) of each vertebra. It's palpable on a person's back.
• Transverse Processes: Two lateral projections on either side of the vertebra.
• Vertebral Foramen: The canal formed by the vertebral body and the vertebral arch, through which the spinal cord passes.
• Superior and Inferior Articular Processes: These projections help to form joints with adjacent vertebrae.

Classification

Based on their location, vertebrae are classified into five main categories:

• Cervical vertebrae: These are the seven vertebrae situated in the neck. The first cervical vertebra, known as the atlas, supports the skull.
• Thoracic vertebrae: Twelve vertebrae located in the chest area, each corresponding to one pair of ribs.
• Lumbar vertebrae: Located in the lower back, these five vertebrae are larger and bear more weight than the thoracic or cervical vertebrae.
• Sacral vertebrae: Five fused vertebrae that form the sacrum in the pelvis.
• Coccygeal vertebrae: Also known as the tailbone, the coccyx comprises three to five (typically four) small fused vertebrae.

Functions

The vertebral column, composed of the individual vertebrae, serves several vital functions:

• Support: It provides structural support, holding the body upright and providing a foundation for muscles and bones.
• Protection: The vertebrae safeguard the spinal cord, which is nestled within the spinal canal.
• Flexibility and Mobility: The vertebral column allows for a significant range of movements, including flexion, extension, lateral bending, and rotation.
• Hematopoiesis: Red bone marrow, found within the vertebral bodies, produces blood cells.

Clinical Significance

Several medical conditions and disorders can affect the vertebrae:

• Osteoporosis: A condition in which bones, including the vertebrae, become brittle and more prone to fractures.
• Herniated Disc: A condition where the intervertebral discs, which cushion between the vertebrae, protrude and can impinge on nerves.
• Spondylosis: Refers to degenerative changes in the spine, including osteoarthritis and degenerative disc disease.
• Vertebral Fractures: Breaks or cracks in any of the vertebrae, often due to trauma or osteoporosis.
• Scoliosis: A lateral curvature of the spine.

Conclusion

The vertebrae are pivotal components of the skeletal system, collectively forming the vertebral column that supports, protects, and facilitates movement for the body. Understanding the structure and function of the vertebrae is crucial for diagnosing and treating many spinal conditions.

See Also

• Spinal Cord
• Intervertebral Discs
• Bone Marrow
• Musculoskeletal System

Vertebra Resources
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