Southwest Orthopaedic Physical Therapy Information Headquarters

Anatomy of the Spine

Posted by Kale Isaacson on Sep 15, 2011 10:11:00 AM

SpineOur spine’s primary job is to act as the “tree trunk” of the body. The spine is made up of 24 bony blocks called vertebrae, stacked one on top of the other. In between each two vertebra is a disc, made out of cartilage rings. The disc acts like a rubber band to absorb shock between vertebrae, and to allow movement in every direction without damaging the bony vertebrae.

The back portion of a vertebra is called the vertebral body. Attached to the backside of the of the vertebral body is a bony arch that creates a canal that houses and protects the spinal cord (an additional function of the spine).

The spine is divided up into 3 different regions: 1) The neck portion of the spine is called the Cervical Spine. The neck’s primary job is to balance the head on top of itself and the shoulders. The average head weighs about as much as a 12 pound bowling ball! That’s like spinning a 12 lb plate atop of a stick like the jugglers do. 2) The part of the spine that the ribs attach to is called the Thoracic Spine. The Thoracic Spine and the ribs allow for breathing but also create a protective “house” for the heart and lungs. 3)The lower back is called the Lumbar Spine. The Lumbar Spine takes on the most load of any portion of the spine mostly because it is at the bottom of the chain of vertebrae. The Lumbar Spine also has the largest of all of the vertebrae.The Lumbar Spine attaches to the pelvis through a group of  five fused vertebrae called the Sacrum. The Sacrum attaches to each half of the pelvis on each side and to the lumbar spine above.Lower Spine

The arch on the backside of a pair of vertebra above and below creates a hole on each side of the spine called a Neural Foramen. The word Neural refers to a Nerve, and the word Foramen refers to an opening or hole. These holes are formed by the vertebrae to allow a spinal nerve to exit out at each segment. A spinal nerve exits on both the right and the left at each segment. A segment describes the anatomy and movement between two vertebrae.

There are joints that are formed between each segment, one on the right and one on the left. These joints are called Facet Joints, and their purpose is to guide the movement of the spine. The Facet Joints are held together by Ligaments. Ligaments attach a bone to a bone. They are made out of Connective tissue which does exactly what the word says; they connect things together, i.e., bones.

In conclusion, think of the spine as the “Electrical Command Post” of the body. Since pain is generated by nerves, one can see that when you have back pain, it can be very confusing to nail down the source of the pain. Your Physical Therapist will ask you a series of questions during your Initial Evaluation, followed by an examination to isolate the exact cause of your pain. I will be writing follow-up Blogs on Risk Factors for spinal pain, posture and the consequences of poor posture, and spinal pain and physical activity. Stay tuned...


Topics: health, physical therapy