The Spinal Cord is connected to the brain and is about the diameter of a human finger. From the brain the spinal cord descends down the middle of the back and is surrounded and protected by the bony vertebral column. The spinal cord is surrounded by a clear fluid called Cerebral Spinal Fluid (CSF), that acts as a cushion to protect the delicate nerve tissues against damage from banging against the inside of the vertebrae.

The anatomy of the spinal cord itself, consists of millions of nerve fibres which transmit electrical information to and from the limbs, trunk and organs of the body, back to and from the brain. The nerves which exit the spinal cord in the upper section, the neck, control breathing and the arms. The nerves which exit the spinal cord in the mid and lower section of the back, control the trunk and legs, as well as bladder, bowel and sexual function.

The nerves which carry information from the brain to muscles are called Motor Neurones. The nerves which carry information from the body back to the brain are called Sensory Neurones. Sensory Neurones carry information to the brain about skin temperature, touch, pain and joint position.

The brain and spinal cord are referred to as the Central Nervous System, whilst the nerves connecting the spinal cord to the body are referred to as the Peripheral Nervous System.

It is important for us that are suffering from spinal cord diseases, injuries or any issues of the spinal cord to know and learn about the function and levels of the spinal cord and it's effects on us. That way, we have more understanding of the pain that we go through. 

Depending on which level of the spinal cord our syrinx is, if we know the function for each level and what nerves it innervates, we will have more understanding of our pain.

Nerves called the spinal nerves or nerve roots, branch off the spinal cord and pass out through a hole in each of the vertebrae called the Foramen. These nerves carry information from the spinal cord to the rest of the body, and from the body back up to the brain.

There are four main groups of spinal nerves, which exit different levels of the spinal cord.

These are in descending order down the vertebral column:

Cervical Nerves "C" : (nerves in the neck) supply movement and feeling to the arms, neck and upper trunk. Also control breathing.
Thoracic Nerves "T" : (nerves in the upper back) supply the trunk and abdomen.
Lumbar Nerves "L" and Sacral Nerves "S" : (nerves in the lower back) supply the legs, the bladder, bowel and sexual organs.

 A person with a syrinx from C1-C4 has the most complications. This is what is referred to as Syringobulbia. This refers to the involvement of the hindbrain. With the involvement of the hindbrain, the degeneration of the disease is faster. There is almost no remission.This is the nature of the disease.

Levels of injury and its effects:

High Cervical nerves C1-C4 - This level has the most complications. Affects arms, hands, trunk and
legs.  Difficulty breathing, controlling bowel and bladder  movements. Ability to speak is sometimes reduced. May not be able to drive a car. And because it affects the trunk, some end up being bedridden. A person might require assistance with daily living.

Low Cervical nerves C5-C8 - Corresponding nerves controls arms and hands.

C5- May affect wrists, hands, trunk and legs. May have breathing difficulty. May need assistance with activities of daily living.