The Spine: Support System for Body
Parts of the Spine
The spine is composed of many moveable parts that function together and allow you to move…
VERTEBRAE – The Bones of the Spine
There are 24 moveable vertebrae in your spine. Each bone is shaped different within the different regions of the spine to allow for specific ranges of movement. They connect to each other by “articulations” that allow smooth movement between the bones. The round part of the vertebra is called the “body” and the pointy part to the back is the “spinous process.”
Within each region, there are a specific number of bones named for their order in that region. 7 cervical vertebrae (C1-C7), 12 thoracic vertebrae (T1-T12), 5 lumbar vertebrae (L1-L5), 1 sacrum and 1 coccyx bone. The coccyx bone is the lowest point of the spine that is commonly known as the tailbone.
Facet Joints:
Facet articulations connect the vertebrae of the spine and allow movement. One facet faces upwards and one faces downward to connect with the adjacent vertebrae above and below.
Disks
There are 23 intervertebral discs (or disc for short) which acts like the shock absorber of the spine. There are cervical spine discs, thoracic spine discs, and lumbar spine discs, Each disc acts as a spacer between the vertebrae and provides for enough space within the vertebral column for the spinal cord and nerves to pass through as they exit to the extremities or limbs of the body. Each disc has a center called the “nucleus pulposus” which is normally 80% water-filled. The outer part is the “annulus fibrosus” which is made of rubberband-like rings (annular fibers) which hold the nucleus in place.
Spinal Cord and Nerves:
The spinal cord is housed and protected between the vertebrae. It gives rise to nerve roots at each vertebral level. The spinal nerves extend from the spinal cord and transmit information from the discs, facet joints, muscles, tendons, and ligaments. The nerves send and receive messages from our brain to the various parts of our body. These nerves interpret information such as balance, touch, pressure, temperature, and if the nerves are excessively compressed or irritated, give us a symptom such as PAIN, numbness or tingling, or even muscle weakness. The brain then produces a response to these signals to determine whether it’s a response of comfort or pain.