Difference Between Backbone and Spinal Cord 

The human body contains several vital structures that support movement, posture, and communication between the body and the brain. Two such essential structures are the backbone and the spinal cord. Although these terms are often mistakenly used interchangeably, they refer to entirely different anatomical components with very different roles. The backbone, also known as the vertebral column, is a bony structure that supports the body and protects the delicate structure inside it. The spinal cord, enclosed within the backbone, is a long bundle of nerve tissue that serves as the key communication pathway between the brain and the rest of the body.

1.0What Is the Backbone?

The backbone, also referred to as the vertebral column or spine, is a strong and flexible column of bones running from the base of the skull to the pelvis. It is part of the skeletal system and functions as the main axial support of the body.

Structural Features of the Backbone

The backbone is made up of 33 vertebrae in an infant, which later reduces to 26 vertebrae in adults due to the fusion of certain bones.

Functions of the Backbone

• Provides structure and supports posture
• Protects the spinal cord
• Helps in movement and flexibility
• Maintains body balance
• Serves as an attachment point for muscles and ribs
• Supports weight distribution during walking, sitting, and lifting

Composition of Vertebrae

Each vertebra consists of:

• Vertebral body
• Vertebral foramen (canal)
• Spinous and transverse processes
• Intervertebral discs (soft cushioning pads)

2.0What Is the Spinal Cord?

• The spinal cord is a long, cylindrical bundle of nerves, part of the central nervous system (CNS), extending from the brainstem down through the vertebral canal.
• It begins at the medulla oblongata and continues downward until the level of the L1–L2 vertebra, where it tapers into a structure called the conus medullaris and later continues as cauda equina nerve fibres.

Functions of the Spinal Cord

• Acts as a communication link between the brain and body
• Transmits motor signals from the brain to muscles
• Transmits sensory signals from the body to the brain
• Coordinates involuntary actions known as reflexes

Structure of the Spinal Cord

The spinal cord is protected by:

• Meninges (Dura mater, Arachnoid mater, Pia mater)
• Cerebrospinal fluid (CSF)
• The vertebral column

The spinal cord contains:

Spinal Nerves

There are 31 pairs of spinal nerves, categorized as:

These nerves are part of the peripheral nervous system and branch out to various organs and tissues.

3.0Difference Between Backbone and Spinal Cord

The backbone and spinal cord differ in structure, function, and physiology. The following table summarizes the differences: