This video tutorial defines dermatomes, how they are tested and why they are clinically important:

• 0.14. Defining dermatomes
• 0:31. Clinical use of the term "dermatome"
• 1:01. Embryological use of the term "dermatome"
• 2:01. Segmental organization of dermatomes
• 2:26. Explanation for red dots on dermatomes image
• 4:03. Testing dermatomes on the body
• 6:59. Variations in dermatome maps
• 8:19. Practice Questions
• 10:59. Acknowledgements