What Are Vertebrae?
Vertebrae are the individual bones that make up your spine, also known as the backbone, spinal column, or vertebral column. They are stacked on top of each other to form a flexible column that protects the spinal cord. In humans, there are 33 vertebrae in total.
- Number and Types: The 33 vertebrae are categorized into five regions: 7 cervical (neck), 12 thoracic (chest), 5 lumbar (lower back), 5 sacral (fused to form the sacrum), and 4 coccygeal (fused to form the tailbone). The vertebrae in each region have unique characteristics that reflect their specific functions. For instance, the atlas (C1) and axis (C2) vertebrae in the neck allow for the unique head rotation and movement. The sacral vertebrae fuse during development, providing a strong base for the pelvis.
- Protection of the Spinal Cord: The vertebrae form a protective canal (spinal canal) that encloses and protects the spinal cord, a crucial part of the central nervous system. The spinal cord carries signals between the brain and the rest of the body.
- Support and Movement: The vertebrae, along with intervertebral discs (soft, gel-like cushions between the vertebrae) and ligaments, provide structural support for the body. The joints between the vertebrae allow for a range of motion, enabling bending, twisting, and other movements of the spine.
- Attachment Points: Vertebrae serve as attachment points for muscles, ligaments, and ribs, contributing to posture, movement, and overall body mechanics.
Variations in Vertebral Structure
While most people have 33 vertebrae, variations can occur. Sometimes, an individual may have an extra vertebra. The sacral vertebrae typically fuse together, but the degree of fusion can vary.
Clinical Significance
The spine is a complex structure, and conditions affecting the vertebrae can cause pain, limited mobility, and neurological problems. Examples include:
- Spinal stenosis: Narrowing of the spinal canal, putting pressure on the spinal cord and nerves.
- Spondylolisthesis: Forward slippage of one vertebra over another.
- Fractures: Vertebral fractures can result from trauma or osteoporosis.
The information above synthesizes details from several resources, including the provided links, which offer further explanation and insights into the anatomy and function of vertebrae. The sources indicate the vertebral column is integral to the vertebrate anatomy, forming the protective sheath for the spinal cord and enabling body movement.
