Difference Between Dermatome and Cutaneous Innervation

The key difference between dermatome and cutaneous innervation is that the dermatome is an area of the skin that is innervated by a single spinal nerve. Meanwhile, the cutaneous innervation is an area of the skin innervated by a specific cutaneous nerve.

Skin is the largest organ that we have. It is the outermost covering of our body. Further, it carries out several functions. It provides protection against microorganisms and other toxic compounds. Also, it helps to regulate our body temperature and facilitates sensations of touch, heat and cold. Besides, to provide sensation and nerve supply to the skin, there are different nerves present in the skin. They are termed as cutaneous nerves. Cutaneous innervation refers to an area of the skin which is supplied by a specific cutaneous nerve. A dermatome is a kind of cutaneous innervation, but it specifically refers to an area that is supplied by a single spinal nerve.

CONTENTS

1. Overview and Key Difference
2. What is Dermatome 
3. What is Cutaneous Innervation
4. Similarities Between Dermatome and Cutaneous Innervation
5. Side by Side Comparison – Dermatome vs Cutaneous Innervation in Tabular Form
6. Summary

What is Dermatome?

A dermatome is an area of the skin which is specifically supplied by a single spinal nerve. In a dermatome, we can find sensory neurons that arise from a spinal nerve ganglion. These nerves are mainly afferent nerve fibres coming from a single dorsal root of the spinal nerve. However, in some cases, dermatome becomes less specific when the spinal nerve acts as a source for several cutaneous nerves. But, most of the times, dermatome is highly specific. Our body has 30 dermatomes. They are numbered based on which spinal nerve they correspond to.

Dermatomes appear as stacks of discs that form a human being. Each dermatome has a specific spinal nerve supply. Thus, each spinal nerve relays sensation from a particular region of the skin to the brain. Most importantly, dermatome innervation is unique to each individual, similar to a fingerprint. The disease symptoms occurring in dermatome indicate pathology related in the nerve root. Therefore, dermatomes are useful in determining whether the sensory loss on a body part is corresponding to a single spinal segment. Moreover, dermatomes are helpful to find out the presence and the extent of a spinal cord lesion.

What is Cutaneous Innervation?

Cutaneous innervation refers to the area of the skin which has a nerve supply by a specific cutaneous nerve. Thus, cutaneous nerves are primarily responsible for providing sensation to the skin.

Cutaneous nerves can be mainly sympathetic and autonomic afferent (sensory) fibres. There are many different cutaneous nerves present in our body.

What are the Similarities Between Dermatome and Cutaneous Innervation?

• Becoming familiar with dermatomes and cutaneous innervations will help practitioners to better understand nerve injury symptoms.

What is the Difference Between Dermatome and Cutaneous Innervation?

A dermatome is an area of the skin which is supplied by a single spinal nerve. Meanwhile, the cutaneous innervation refers to an area of the skin innervated by a specific cutaneous nerve. So, this is the key difference between dermatome and cutaneous innervation.

Summary – Dermatome vs Cutaneous Innervation

Cutaneous nerves are the nerves that provide nerve supply to the skin. There are many cutaneous nerves in our skin. Cutaneous innervation refers to an area of the skin supplied by a specific cutaneous nerve. Meanwhile, the dermatome is a specific area of the skin which receives nerve supply by a spinal nerve. It is a kind of cutaneous innervation. But, it is more specific since it is supplied by fibres from a single nerve root. Thus, this summarizes the difference between dermatome and cutaneous innervation.

Reference:

1. Baglien, Peter. “Anatomy, Shoulder and Upper Limb, Cutaneous Innervation.” StatPearls [Internet]., U.S. National Library of Medicine, 22 July 2019, Available here.
2. Seladi-Schulman, Jill. “Dermatomes Diagram: Spinal Nerves and Locations.” Healthline, Healthline Media, 15 July 2019, Available here.

Image Courtesy:

1. “1611 Dermatomes-02” By OpenStax Anatomy and Physiology – (CC BY 4.0) via Commons Wikimedia
2. “Gray812and814” By Henry Vandyke Carter – This is a retouched picture. Modifications made by Fred the Oyster., (Public Domain) via Commons Wikimedia