Vertebral Column, Vertebral (Spinal) Canal, and Spinal Cord

Abstract

The spinal column serves many remarkable functions. It supports the weight of the head, acts as the central pillar of the body, connects the upper and the lower segments of the trunk, gives attachments to the ribs, reduces shock transmitted from various parts of the body, forms a complete tube for the reception of the spinal cord and permits a wide range of most complicated movements and balancing. It consists of 33 vertebrae which are grouped according to region (Fig. 795). The movable (true) vertebrae are the 7 cervical, the 12 thoracic and the 5 lumbar. The fixed (false) vertebrae are the 5 sacral, fused in adults to form the sacrum, and usually the 4 coccygeal, fused to form the coccyx. If the bony column is examined as a whole from front or back it seems to form a straight line, but when it is seen from the side it presents definite curves.