About this post: Understanding
Spinal Anatomy – Introduction.
The spine supports the body between the head and pelvis and is composed of 32 to 34 individual vertebra. Although all vertebrae share the same general characteristics, they vary in appearance and size, as well as function differently, with five regional groupings:
The Regional vertebra are:
Seven cervical vertebrae are known as the cervical spine
Twelve thoracic vertebrae are known as the thoracic spine.
Five lumbar vertebrae are known as the lumbar spine.
Five sacral vertebrae fused together known as the sacrum.
Three to five coccygeal vertebrae are known as the coccyx.
Conclusively it can be stated that we usually have 24 pre-sacral vertebrae, and 23 discs in the spaces between these vertebrae.
Identifying the Vertebra
To identify a vertebra, a Regional precursor and a consecutive number is used. The last cervical vertebrae is called C7, the first thoracic vertebra is called Th1. The disc between them would be C7/Th1 (or T1).
The last Thoracic vertebrae is named Th12, the first Lumbar vertebra L1. The disc between them is called Th12/L1
The last Lumbar vertebrae is called L5, the first sacral vertebra (usually the sacral vertebrae are fused), is called S1. The disc between them is called L5/S1.
A vertebral unit of movement consists of two adjacent vertebrae with a disc in-between.
Movement between these two adjacent vertebrae takes place by the so-called three-joint complex, consisting of the intervertebral disc joint as well as two facet joints.
Except for the first cervical vertebra all other vertebrae consist of a body. All vertebrae have a bony neural arch. The bony arch consists of two pedicles and two laminae to which are attached 7 bony processes.
Various regions differ in appearance and size. Vertebrae become larger the lower down the spine you look. There are many differences between different areas because of the functional needs of the specific region.
Anatomy of the Cervical Vertebrae
In comparison, the first and second cervical vertebrae differ anatomically from the remaining cervical vertebrae.
Anatomy of the Thoracic Vertebrae
Twelve Thoracic Vertebrae are anchored by the Ribs and Ribcage.
Movement in the Thoracic Vertebrae is much less than in the Cervical Spine as well as the Lumbar Spine. The transition areas between the cervical and thoracic vertebrae (C7/Th1) as well as the thoracic and the lumbar vertebrae (Th12/L1) are particularly vulnerable to injuries.
Anatomy of the Lumbar Vertebrae
The lumbar vertebrae are subjected to high levels of stress and strain. Millions of working days are lost throughout the world because of distressing back pain.
Anatomy of the Sacrum
The sacrum is a wedge-shaped bone of fused vertebrae on which the Lumbar spine rests and moves. It is wedged between the two Pelvic bones and forms part of the pelvic ring protecting the pelvic organs.
Acknowledgement of the following pictures and Animations are appreciated below:
- Spinal drawing – Lydia
- Picture – Three joint complex – Adrian
- All Cervical, Thoracic, Lumbar, Sacral and Coccyx are 3D Images and Animations by Anatomography
Also read “determine management plan”
Credit Featured Image: photo of bird, beak, fauna, wildlife, organism, water bird-creative commons CC0