The spinal cord is a part of the nervous system; it is essentially a collection of nerve extending from the base of the brain to the lower back. It is a long, thin, cylindrical nervous s structure running through the vertebral column.

The spinal cord along with the brain makes up the central nervous system; the peripheral nervous system being the other division of the nervous system, which includes all the other nerves in the body.

The spinal cord is a complex structure acting as an information pathway between the brain and other parts of the body; it is protected by a bony cage called the vertebral canal or column. Its functions vary from simple day to day task like standing, walking and running to more complex functions like reflexive actions.  Let us look at the basic spinal cord anatomy.

Spinal cord segments

spinal cord

what is spinal cord

The spinal cord is a little longer in men than in women, measuring about 45cm length in men, and 43cm in women; 18 and 17 inches respectively. It is composed of 31 segments which are all located inside the vertebral canal. The spinal nerves are numbered and named in accordant with the site of their emergence from the vertebral column.

Eight (8) cervical segments: These are the first part of the spinal cord, located in the neck. They are traditionally denoted by C1-C8 passing in between the neck bones -atlas and axis.

Twelve (12) thoracic segments: They are 12 pairs of thoracic nerves, passing through the thoracic (chest) region of the spinal cord. They are traditionally represented as T1 to T12.

Five (5) lumbar segments: The lumbar segments pass through the part of the vertebral column named as the lumbar vertebra, which is at the abdominal region. They are denoted with L1-L5.

Five (5) sacral segments: they pass through the sacral vertebra in the pelvic region, they are five pairs of sacral nerves, represented as S1-S5.

One coccygeal segment: The coccygeal contain the caudal nerve; it is the last part of the vertebral column, referred to as the tailbone. The bone is said to be the remnant of an evolutionary tail in man.

Spinal tissues and tract

The spinal cord just like the brain is made of two tissue types; the grey matter (a pinkish-gray colored, butterfly-shaped part containing its cell bodies, axons terminals, dendrites, and nerve synapses) and the white matter which composed axon bundles.

It also contain tracts whichare the wires in your spinal cord -connecting it to the brain, they oversee the transmission of information between the brain and your body parts.

They are largely divided into ascending and descending tracts with both divisions further subdivided.

Blood supply to the spinal 

The only way our body get nutrient is via blood. The spinal cord is supplied by descending branches of the vertebral artery and multiple smaller arteries called radicular arteries. Blood is also taken away from the spinal cord via a similar distribution.

Functions of the spinal cord

Ability to stand and walk is so basic to us that we don’t really think about what makes it possible. The spinal cord offers support to the body, without it, we wouldn’t have been able to run, walk or even stand.

The spinal cord also serves as an electrical conduit that transmits electrical signals from the body up to the brain and supplies the interpretations from the brain to other parts of the body. Your ability to react to events is basically because of the presence of the spinal cord, it is just like electrical wires transmitting power from the source to your house; there wouldn’t be power in your home without the electrical wires. The spinal cord is your electrical wire.

pointing in a spine bone 

Additionally, the spinal cord controls all the involuntary response. The brain deputies the spinal cord with involuntary actions like urinating; the reason you see patients with spinal cord injury losing their bladder control.

Spinal Cord Injuries

The knowledge of the spinal cord anatomy is essential to understanding the spinal cord injuries. The injuries are divided into complete and incomplete with the commonest example being anterior cord syndrome, Brown-Sequard syndrome, tetraplegia and paraplegia.


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