DiskHerniaion-Eng.doc

BASIC STRUCTURE FUNCTION OF THE SPINE VERTEBRAL COLUMN The vertebral column or spine is made up of a series of bones called vertebrae. The spine is a strong and flexible column of bones made up of the cervical, thoracic, lumbar, sacral, and coccygeal regions. The cervical or neck region is normally made up of 7 bones, the thoracic or chest region has 12 bones, and the lumbar or low back region is made up of 5 bones. The sacral region consists of 5 fused bones, and the coccygeal region 3 to 5 tiny bones. However variations do occur. The spine is curved and in profile looks like an elongated letter S in shape. The cervical and lumbar regions have a forward curve and the thoracic region a backward curve when viewed from the side. It has been suggested that the S shape of the spine: facilitates energy absorption and protects the spinal structures against impact by increasing its strength; helps maintain balance in the upright position; and absorbs shocks when a person walks. SIDE VIEW OF THE SPINE KEY POINT The vertebral column or spine is made up of a series of bones called vertebrae. Variation in vertebrae size, shape and detail occur in the different regions of the spine. For example, the lumbar vertebrae are the largest and strongest. In general, however, all vertebrae have the same basic structure. There are three main parts to a vertebra: Vertebral Body (weight bearing structure) Vertebral Arch (protective in function) Vertebral Processes VERTEBRAL BODY The vertebral body is the weight bearing part of a vertebrae. The vertebral body is a thick, disc shaped cylindrical block of bone flattened at the back and with roughened top and bottom surfaces. It is made up of spongy bone on the inside, which enables it to resist compression, and a thin outer covering of compact bone. It is the weight bearing part of a vertebrae. VERTEBRAE Side View View From Above VERTEBRAL ARCH The vertebral arch surrounds the spinal column and is protective in function.