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.
An individual vertebra is made up of several parts. The body of the vertebra is the primary area of weight bearing and provides a resting place for the fibrous discs which separate each of the vertebrae. The lamina covers the spinal canal, the large hole in the center of the vertebra through which the spinal nerves pass. The spinous process is the bone you can feel when running your hands down your back. The paired transverse processes are oriented 90 degrees to the spinous process and provide attachment for back muscles.
The human spine is made up of 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column. The spinal column is the body's main upright support.From the side, the spine forms three curves. The neck, called the cervical spine, curves slightly inward. The thoracic spine curves outward. The low back, also called the lumbar spine, curves slightly inward. An inward curve in the spine is called lordosis. An outward curve, as in the thoracic spine, is called kyphosis. The kyphosis is shaped like a C with the opening in front.
The middle 12 vertebrae make up the thoracic spine. Doctors often refer to these vertebrae as T1 to T12. The large bump on the back of the lower part of the neck is the seventh cervical vertebra, called C7. It connects on top of T1. The lowest vertebra of the thoracic spine, T12, connects below the bottom of the rib cage to the first vertebra of the lumbar spine, called L1.