Understanding the fundamental anatomy and function of the spine is key to understanding injuries to and diseases of the spine.
The spine has several special roles in the human body. It:
- Protects the spinal cord (which connects nerves to the brain);
- Provides the support needed to walk upright;
- Enables the torso to bend;
- Supports the head.
Viewed from the side, the spine has a natural “S” curve, which should not to be confused with the abnormal curvature of scoliosis.
The main sections of the spine
- Cervical – commonly referred to as the neck. There are seven cervical vertebrae (doughnut-shaped bones) that connect the skull to the rest of the spine.
- Thoracic – The spine’s thoracic section begins at the shoulders and extends down to the end of the rib cage. There are 12 vertebrae in the upper back, with shock-absorbing disks between them. Scoliosis commonly affects the thoracic section of the spine.
- Lumbar – The lumbar section, or lower back, has five vertebrae. These vertebrae, separated by disks, are the largest in the spine. The lumbar section is also a common location for scoliosis to occur.
- Sacrum – There are five vertebrae that join together to form the sacrum, a wedge-shaped part of the spine that rests at the top of the pelvis.
- Coccyx – often referred to as the tailbone, consists of four vertebrae.
- Vertebrae – The spine has 33 doughnut-shaped bones called vertebrae. Each vertebra is assigned a letter and a number that identifies its location in the spine.
- Disks – Between each pair of vertebrae is a spongy cartilage, or disk. Intervertebral disks act as shock-absorbing cushions. Spongy disks are located between the vertebrae.