Anatomy of the spine

In the strict anatomical sense of the term, the spine is a set of bones, each of which is called a vertebra.

In practice, however, this term also refers to the inside of the spine, i.e. the spinal cord with the beginning of the nerves and the outside with the muscles and ligaments. It consists of 33 bones, called vertebrae, which are placed on top of each other. The vertebrae have an anterior part called the body and a posterior part called the petal. Between the body and the petal there is a small gap called a hiatus. When the vertebrae are placed vertically, these gaps form a tube called the vertebral canal. Within the vertebral canal runs protected the spinal cord, which is a basic unit of the Central Nervous System.

The vertebrae are differentiated and so the anatomists divided the spine into five segments (degrees) :

1. Cervical fossa or neck from the base of the head to the proximal vertebra i.e. the bone that we feel at the back of the neck when we bend our head. It includes 7 vertebrae.

2. Thoracic spine from the proximal vertebra to the beginning of the waist. It includes 12 vertebrae.

3. Lumbar fossa or waist from the end of the thoracic fossa to the beginning of the sacrum. Includes 5 vertebrae.

4. Sacral fossa. Includes 5 vertebrae joined together to form the sacrum.
5. Coccygeal fate. Includes 4 very small vertebrae, joined together, forming the coccyx.

Degenerative diseases are those whose aetiology is the progressive deterioration of the spine, due to age, hereditary factors, poor posture, continuous stress on the spine due to occupation or systemic diseases.

Degenerative diseases of the spine can affect almost all spinal structures:

Discs: Intervertebral discs usually change with age. Intervertebral discs tend to change with age; they may collapse slightly and "dry out," a condition called degenerative disc disease. Any damage to the inside of the disc can cause severe back pain. If all the layers of the annulus are ruptured the nucleus pulposus leaks out of the disc, causing a herniation of the disc or disc protrusion. A cyclic projection or herniated intervertebral disc can compress the spinal nerves, causing dysfunction manifested as muscle weakness, loss of sensation in the skin, numbness or burning along the nerve and, of course, pain. This condition is called a herniated disc.

Bones and cartilage: As the cartilage in the joints wears away, the vertebrae or bony structures at the back of the spine may "rub" against each other. Mechanical friction between bones is the major cause of pain and stiffness in the back and lumbar spine.