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Difference Between Spinal Cord and Backbone

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Spinal cord

The spinal cord is a long, delicate structure of a tube that starts at the end of the stem of the brain and goes down almost to the bottom of the spine. Nerves that carry incoming and outgoing signals between the brain and the rest of the body consist of the spinal cord. For reflexes, such as the knee jerk reflex, it is also the centre. 

Three layers of tissue protect the spinal cord, like the brain (meninges). In the spinal canal, which runs along the middle of the spine, the spinal cord and meninges are located. The spine is composed of 33 individual backbones in most adults (vertebrae). Much like the skull covers the brain, the spinal cord is covered by vertebrae.

Disks made of cartilage, which serve as cushions, separate the vertebrae, minimizing the forces produced by movements such as walking and jumping. The cartilage vertebrae and discs stretch the length of the spine and form the vertebral column together, often referred to as the spinal column.

The spinal cord, like the brain, consists of gray and white matter. The cord's butterfly-shaped core is made of gray matter. There are motor nerve cells (neurons) in the front wings (also called horns) that relay information from the brain or spinal cord to muscles, stimulating movement. Sensory nerve cells include the back horns, which relay sensory information to the brain from other parts of the body via the spinal cord. The surrounding white matter comprises columns of nerve fibres from the rest of the body (ascending tracts) that carry sensory input to the brain and columns that carry motor impulses from the brain to the muscles (descending tracts).


Organization of the Spine

The spine is made up of a column of bones called vertebrae (spinal column). The spinal cord, a long, fragile structure contained in the spinal canal which runs through the centre of the spine, is protected by the vertebrae. Disks made up of cartilage are between the vertebrae, which help cushion the spine and give it some flexibility.

Three layers of tissue protect the spinal cord, like the brain (meninges).

1. Spinal Nerves:

There are 31 spinal nerve pairs arising from the spinal cord between the vertebrae. Two short branches (roots) emerge from each nerve: 

  • One at the front of the spinal cord (motor or anterior root) 

  • The one at the back of the spinal cord (sensory or posterior root)

The motor roots carry commands, particularly skeletal muscles, from the brain and spinal cord to other parts of the body. 

The sensorial roots bring information from other parts of the body to the brain.

2. Cauda Equina: 

About three-fourths of the way down the spine, the spinal cord stops, but a bundle of nerves stretches beyond the cord. This bundle, since it resembles the tail of a horse, is called the cauda equina. Nerve impulses are carried by the cauda equina to and from the legs.


Backbone

Backbone is another name that the vertebral column is used to identify. A flexible column that runs from the neck to the tail of the vertebrate body is the vertebral column. The primary characteristic used to distinguish vertebrates from other chordates is usually the presence of a vertebral column.

A notochord is usually formed by chordates; this notochord can be identified only during embryonic development in vertebrates. Later, it grows into the vertebral column. In addition, the vertebral column consists of a series of vertebrae grouped as cervical, thoracic, lumbar, sacral, and coccygeal vertebrae and is a bony structure. Humans have a backbone of 33 vertebrae.

In addition, housing the spinal canal is the main feature of the vertebral column or backbone; the spinal cord extends from head to tail within this canal. It also provides the spinal cord with protection and provides sites for the nerves to emerge from the spinal cord.

The spinal cord is basically one of the two components of the central nervous system, while the brain is the second component. Here, the backbone provides muscles such as pectoral and pelvic girdles and many muscles for attachment sites. In addition, when standing and walking, the backbone transmits body weight into the pelvis.


What is the Difference Between Spinal Cord and Backbone?

The key distinction between the backbone and the spine is that the more informal term for the vertebral column is the backbone, whereas the more formal term is the spine.


Spinal Cord

Backbone

Composition

Consisting of bundles of nerve fibres.

The backbone consists of bones known as vertebrae.

Function

The spinal cord serves as a means of contact between the body and the brain. 

The backbone helps to provide structural assistance as well as carry the weight of the body. It is also charged with spinal cord security.

Segments

31 segments are formed by the spinal cord, divided into 8 cervical nerves, 5 lumbar nerves, 1 coccygeal nerve, 12 thoracic nerves, and 5 sacral nerves.

The backbone of the cervical spine, the thoracic spine and the lumbar spine, sacrum and coccyx can be divided into 5 main parts. There are 7 bones called vertebrae in the cervical spine. There are 12 vertebrae of the thoracic spine and five vertebrae of the lumbar spine.


Conclusion:

The more casual word to define the vertebral column, which is the vertebrate body's most distinctive characteristic, is the backbone. It consists of a series of vertebrae which are divided by intervertebral discs. The spine is the more formal term used to define the vertebral column, on the other hand. The only difference between the backbone and the spine is, therefore, the use of the term.

FAQ (Frequently Asked Questions)

1. What Does a Spinal Disc Mean?

Ans. The soft pad located between each of the vertebrae of the spine is a disk. As a spacer, shock absorber, and part of the cartilaginous joints that allow movement in the spine, the vertebral disc works. Compression and other stresses can be withstood by the disc, thus allowing a great deal of motion and versatility. Two components consist of intervertebral discs - a strong outer part (annulus fibrosus) and a softer inner centre (nucleus pulposus). Like two concentric cylinders, the annulus fibrosus and the nucleus pulposus fit together and the configuration can be represented as a jelly doughnut. The spinal column comprises a total of twenty-three vertebral discs.

2. How Many Vertebrae are there that Make Up the Spine?

Ans. The average person is born with 33 individual bones. By the time an individual becomes an adult, most of the individuals are left with only 24 vertebrae, as during normal growth and development, some vertebrae at the lower end of the spine get fused together.

A sacrum is considered the bottom of the spine. It is composed of multiple vertebral bodies that are normally united as one. The remaining tiny bones or ossicles are also fused together below the sacrum and are called the tailbone or coccyx. Above the sacrum, the spine consists of:

  • In the body, seven bones - the cervical spine. 

  • In the chest, 12 bones - the thoracic spine. 

  • In the lower back, five bones - the lumbar spine.