Nervous System

Your brain is constantly taking in millions of pieces of information. This information is processed and commands are sent our throughout the body. It may be a command for the heart to beat faster, the blood pressure to regulate, to pick up a fork, to throw a baseball or even to cook food. These commands are sent through billions of nerves that come out of the skull and run down the spine.

Nerves Everywhere

Your entire body is covered with nerves. There are millions of nerve fibers that carry information to organs, tissue and all other aspects of your body. These nerves may heal if damaged, but new nerves do not grow to replace damaged ones. This is why a person who suffers a massive stroke may never recover, or a child who us born with brain damage will likely be an adult with brain damage.

Protection

The spine and brain need protection from damage; hence they are covered by bone. Your brain is surrounded by a bone called the skull and the spine is surrounded by 33 bones called vertebrae. It is through these 33 vertebrae that the spinal cord travels, and the bones stacked to protect them are called the spinal column.

The Cervical Spine (Neck)

Neck bones are called cervical vertebrae. The atlas, or first cervical vertebra is directly below your skull. The axis is the second cervical vertebrae and it permits the head to turn and tilt. The Cervical vertebrae are numbered, the atlas is C1, the axis is C2, and the following are C3, C4, C5, C6 and C7.

The Thoracic Spine (Chest)

There are 12 thoracic Vertebrae and they are numbered T1 to T12. The ribs are attached to the Thoracic vertebrae and attach in front to your breastbone or sternum.

The Lumbar Spine (Low Back)

 Here are five lumbar vertebrae numbered from L1 to L5. They are the biggest and thickest vertebrae in the body because they are located at the bottom of the body and must support your weight. This is the reason that low back pain is common, as these vertebrae are an integral part of your day-to-day activity.

The Sacrum

Under the lumbar vertebrae is the sacrum, which is triangular in shape and made up of five fused vertebrae. The sacrum connects to the hips one either side of the body.

The Coccyx (Tailbone)

The coccyx is located under the sacrum, and is a little piece of bone made up of four fused vertebrae. 

Discs

Between most of the vertebrae are discs that act as shock absorbing pads to keep the vertebrae from striking each other.