What is the Difference Between Spinal Cord and Spinal Column

The main difference between spinal cord and spinal column is that the spinal cord is one of the two components of the central nervous system, whereas the spinal column is a part of the axial skeleton made up of a series of vertebrae, separated by intervertebral disks. Furthermore, the spinal cord runs inside the spinal column while the spinal column is a bony structure. In addition to these, the spinal cord is mainly responsible for transmitting nerve impulses from the peripheral to the brain, while the spinal column protects the spinal cord and supports the head and the thorax. 

In brief, the spinal cord and spinal column are two, functionally-related anatomical structures that extend from the neck to the tail of vertebrates. 

Key Areas Covered 

1. What is Spinal Cord
     – Definition, Anatomy, Function
2. What is Spinal Column
     – Definition, Anatomy, Function
3. What are the Similarities Between Spinal Cord and Spinal Column
     – Outline of Common Features
4. What is the Difference Between Spinal Cord and Spinal Column
     – Comparison of Key Differences

Key Terms 

Brain, Central Nervous System, Spinal Column, Spinal Cord, Vertebrae

What is Spinal Cord 

The spinal cord is one of the two components of the central nervous system, the second being the brain. It is also a thin, long, and tubular structure that runs through the spine. In addition, the spinal cord begins from the medulla oblongata in the brainstem and extends to the lumbar region of the spine. Generally, the length of the spinal cord is 45 cm in men and 43 cm in women. Its diameter is 13 mm in both cervical and lumbar regions while 64 cm in the thoracic region. Meanwhile, it contains a central canal filled with cerebrospinal fluid.

Figure 1: Spinal Cord

Furthermore, the main function of the spinal cord is to transmit nerve impulses from the sensory neurons of the peripheral nervous system to the brain and from the motor cortex of the brain to the effector organs through motor neurons. Therefore, the brain mainly coordinates the voluntary functions of the body through the spinal cord. On the other hand, the spinal cord contains many reflex arcs which control the involuntary functions of the body. In addition, spinal interneurons produce a type of neural circuits called central pattern generators, coordinating motor instructions for rhythmic movements. 

What is Spinal Column 

The spinal column is the series of vertebrae which enclose the spinal cord in vertebrates. It is also a part of the axial skeleton. The spinal column is one of the several distinguishing features of vertebrates. However, all chordates have a notochord, which is replaced by the spinal column in vertebrates. Each of the vertebrae in the column is separated by an intervertebral disc. Meanwhile, the other names for the spinal column include the spine, vertebral column, and backbone.

Figure 2: Spinal Column

Moreover, the bony structure of the spinal column consists of thirty-three vertebrae in humans. They are grouped as cervical, thoracic, lumbar, sacral and coccygeal vertebrae. There are seven cervical vertebrae, twelve thoracic vertebrae , and five lumbar vertebrae in the spine. In addition to these, the next five vertebrae are fused to form the sacrum while the lowest four forms the coccyx or the tail bone by fusion. Furthermore, the main function of the spinal column is to house and protect the spinal cord. It provides sites for the spinal nerves to run out of the spinal cord. Also, it supports the head and thorax while transmitting bodyweight towards the pelvis while standing and walking. On the other hand, the spinal column provides sites for the attachment of muscles. 

Similarities Between Spinal Cord and Spinal Column 

• Spinal cord and spinal column are two anatomical structures which extend from the neck to the tail of vertebrate animals. 
• Moreover, they are two of the several distinguishing features of vertebrates. 
• Both have closely-related functions, permitting the transmission of nerve impulses between the brain and the peripheral nervous system while controlling involuntary movements of the body. 

Difference Between Spinal Cord and Spinal Column 

Definition 

Spinal cord refers to the cylindrical bundle of nerve fibers and associated tissue enclosed in the spine and connects nearly all parts of the body to the brain while the spinal column refers to the series of bones known as vertebrae separated by intervertebral discs. 

Significance 

Furthermore, the spinal cord is one of the two components of the central nervous system while the spinal column is a part of the axial skeleton.

Made up of 

While the spinal cord is made up of nerve tissue, the spinal column is made up of bones. 

Function 

Moreover, the spinal cord is mainly responsible for transmitting nerve impulses from the peripheral to the brain while the spinal column protects the spinal cord and supports the head and the thorax. 

Conclusion 

The spinal cord is one of the two components of the central nervous system of vertebrates, extending from the brain to the tail. Moreover, it is made up of nerve tissue.  The main function of the spinal cord is to transmit nerve impulses between the brain and the peripheral nervous system. In addition to these, it controls the involuntary movements of the body. The spinal column, on the other hand, is the bony structure made up of a series of bones called vertebrae. However, the spinal cord runs through the spinal column. Therefore, the spinal column protects the spinal cord. Hence, the main difference between spinal cord and spinal column is anatomy and function. 

References:

1. “Spinal Cord & Column.” Spinal Cord Injury Information Pages, Available Here.

Image Courtesy:

1. “Nervous system diagram” By ¤~Persian Poet Gal (talk) – Own work (Public Domain) via Commons Wikimedia     
2. “Illu vertebral column“(Public Domain) via Commons Wikimedia