Anatomy of the Spine

Physicians Specializing In the Spine:

Richard Mannion, M.D., F.A.C.S.

The normal anatomy of the spine is usually described by dividing up the spine into 3 major sections: the cervical, the thoracic, and the lumbar spine. (Below the lumbar spine is a bone called the sacrum, which is part of the pelvis).

Each section is made up of individual bones called vertebrae. There are 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae.

Each disc is made up of two parts. The hard, tough outer layer called the annulus surrounds a mushy, moist center termed the nucleus. When a disc herniates or ruptures, the soft nucleus spurts out through a tear in the annulus, and can compress a nerve root. The nucleus can squirt out on either side of the disc or in some cases both sides.

The amount of pain associated with a disc rupture often depends upon the amount of nucleus that breaks through the annulus, and whether it compresses a nerve. To help alleviate the pain, a Laminotomy/Microdiscectomy may be performed.