Question

to detect a damaged spinal nerve you can put ice on the skin's surface called a(n):

analgesic
dermatome
melanin
trigeminal

Answer 1

this question isn't worded very well, but I believe it is referring to the skin, not the ice itself

in this case, we must research the definition of each term

analgesics are painkillers, so that doesn't quite work
melanin is a compound that gives skin and hair its color, but it's mostly located near the basal cells at the bottom of the epidermis, so this doesn't work
trigeminal refers to the trigeminal nerve, which is a nerve that carries sensory input from the face to the brain, so that doesn't quite work here

so going off dermatome, which is the area of skin supplied by one nerve, is the only reasonable answer

references: https://emedicine.medscape.com/article/1878388-overview
https://www.medicalnewstoday.com/articles/melanin#:~:text=Melanin%20is%20a%20substance%20that,of%20melanin%20in%20their%20skin.
https://www.rch.org.au/anaes/pain_management/Assessment_of_sensory_block/