The Sections of the Spinal Column
Cervical Spine
5 Vertebrae (C1 - C5)
Cervical Collars (C-Collars) are so named because they immobilize this section.
Most vulnerable section of the spinal column. Thoracic, Sacrum, and Coccyx sections support by other bony structures, protecting from over extension or flexion that causes vertebrae injuries.
Supports head, which weighs 17 lbs, is relatively poorly supported by muscles/other anatomy, and head and neck move independently, increasing susceptibility to injury.
C1 and C2 (Known as Atlas and Axis, respectively) are very unique vertebrae. The Atlas is just under the head. The axis has what is called the odontoid process (its anterior surface is an oval or nearly circular facet for articulation) about which the atlas rotates. The joint between the atlas and axis is a pivot type of joint. It allows the head turn from side to side.
Thoracic Spine
12 Vertebrae (T1 - T12)
Built for stability, plays an important role in holding the body upright and providing protection for the vital organs in the chest.
The rib cage is connected to thoracic spine. One rib is connected firmly on each side of each thoracic vertebra. T1-T10 connect anteriorly to the Sternum, while T11 and T12 do not (free floating), but do protect the Kidneys.
Lumbar Spine
5 Vertebrae (L1 - L5)
Comes from the Latin word “Lumbus,” meaning “Lion.”
Built for both power and flexibility - lifting, twisting, and bending. The five vertebrae of the lumbar spine are the biggest unfused vertebrae in the spinal column, enabling them to support the weight of the entire torso.
Like the Cervical Spine the Lumbar is not well supported by other anatomical structures and bears the most weight of any spinal section, leaving it susceptible to injury.
The spinal cord ends at the point of connect between T12 and L1. At that point numerous nerve roots from the spinal cord continue down and branch out, forming the "cauda equina.” These nerves extend to the lower extremities (buttocks, legs and feet). Because the spinal cord does not run through the lumbar spine, it is quite rare that lower back injuries would result in spinal cord damage or paralysis.
Sacrum Spine
Triangular-shaped bone and consists of five segments (S1-S5) that are fused together.
As part of the pelvic girdle, the sacrum forms the back wall of the pelvis and also forms joints at the hip bone.
A healthy sacral region is rarely fractured except in instances of serious injury.
Coccyx Spine
Also known as the “Tailbone”
Depending on an individual’s development, the coccyx may consist of three to five vertebrae connected by fused—or semi-fused—joints. It’s generally assumed to be 4 vertebrae.
Although the tailbone is considered vestigial (or no longer necessary) in the human body, it does have some function in the pelvis. It is one part of a three-part support for a person in the seated position. Weight is distributed between the bottom portions of the two hip bones (or ischium) and the tailbone, providing balance and stability when a person is seated.
Injury to the Coccyx is more common in women. Women tend to place more weight on the coccyx when sitting and during childbirth there can be acute damage as the baby moves over the tailbone.
