The Probert Encyclopaedia of Medicine

SPINOUS PROCESS

The spinous process is a projection of bone from the arch of almost every vertebra toward the posterior. This projection is located at the apex of the arch and bordered on the arch by the laminae. It is the series of these processes which is visible as the bumps beneath the skin on the back. The spinous process serves as an anchor point for ligaments which help control the flexibility of the spine. The vertebrae feature different types of spinous processes. Typical cervical vertebrae have bifid spinous processes, with the exception of the atlas which has no
spinous process. Thoracic vertebrae generally have a single tubercle, and point downward as well as back. The lumbar vertebrae feature spinous processes which are rectangular or hatchet-shaped and have a section which points back and one which points down. The spinous processes of the sacrum and coccyx are generally fused together, to form a ridge called, in the sacrum, the sacral crest. Often, the coccygeal vertebrae (fused or not) show no evidence of any ridge, crest, or
spinous process.
Research Spinous Process