The vertebral canal, also known as the spinal canal or spinal column, is a long, narrow, hollow tube that runs through the center of the vertebral column. It is a crucial part of the human anatomy, as it protects and supports the spinal cord, a vital part of the central nervous system.
Structure
The vertebral canal is formed by the vertebral bodies, the intervertebral discs, and the vertebral arch. The vertebral bodies are the large, circular bones that make up the main part of the vertebrae. They are stacked on top of one another, forming the vertebral column. The intervertebral discs are thin, flexible discs that lie between the vertebral bodies. They act as shock absorbers, helping to cushion the spine and distribute weight evenly. The vertebral arch is made up of two bony processes, called the pedicles and laminae, that project out from the vertebral body. The pedicles and laminae join together at the back of the vertebral body to form the vertebral arch, which encloses the spinal canal.
The spinal canal is not a continuous, straight tube. Instead, it is made up of a series of small, interconnected canals that run through each vertebral body. These canals are lined with a thin layer of connective tissue called the dura mater. The dura mater forms a protective sheath around the spinal cord and serves to anchor the spinal cord in place.
Location
The vertebral canal runs through the entire length of the vertebral column, from the base of the skull to the sacrum. The vertebral column is made up of 33 vertebrae, which are divided into five regions: the cervical, thoracic, lumbar, sacral, and coccygeal regions.
The cervical region, or neck, is made up of seven vertebrae. The first two vertebrae, the atlas and axis, are responsible for allowing the head to move freely. The remaining five vertebrae in the cervical region are referred to as cervical vertebrae.
The thoracic region, or chest, is made up of 12 vertebrae. These vertebrae are larger and more robust than the cervical vertebrae, as they have to support the weight of the rib cage.
The lumbar region, or lower back, is made up of five vertebrae. These vertebrae are the largest and strongest in the vertebral column, as they have to support the majority of the body’s weight.
The sacral region is made up of five fused vertebrae, known as the sacrum. The sacrum is a triangular-shaped bone that forms the base of the spine and is responsible for transmitting the weight of the upper body to the pelvis.
The coccygeal region is made up of four small, fused vertebrae, known as the coccyx or tailbone. The coccyx is a vestigial structure that serves no functional purpose in humans.
Function
The main function of the vertebral canal is to protect and support the spinal cord. The spinal cord is a vital part of the central nervous system and is responsible for carrying messages between the brain and the rest of the body. It runs through the vertebral canal, protected by the bony vertebrae and the dura mater.
The vertebral canal also serves as a passageway for nerves that emerge from the spinal cord and travel to the rest of the body. There are 31 pairs of spinal nerves, which exit the vertebral canal through small openings between the vertebrae called intervertebral foramina.
In addition to its protective and supportive functions, the vertebral canal also plays a role in the movement of the spine. The intervertebral discs allow the spine to bend and twist, while the various curvatures of the spine (such as the lordotic curve of the lumbar spine) help to distribute weight evenly and absorb shock.
Clinical Significance
There are several conditions that can affect the vertebral canal and the structures within it. One common condition is a herniated disc, which occurs when the intervertebral disc bulges or ruptures, putting pressure on the spinal cord or spinal nerves. This can cause pain, numbness, and weakness in the affected area.
Other conditions that can affect the vertebral canal include spinal stenosis, which is a narrowing of the canal that can put pressure on the spinal cord; spinal fractures, which can occur due to trauma or osteoporosis; and spondylolisthesis, which is a condition in which a vertebra slips out of place and puts pressure on the spinal cord.
Treatment for these conditions may include medications, physical therapy, or surgery. In severe cases, surgery may be necessary to remove a herniated disc or to stabilize a fractured vertebra.
