https://www.sciencing.com/2000056/useless-organ-arrector-pili-explains-why-humans-get-goosebumps/
Arrector Pili Is A 'Useless' Body Part That Explains Why Humans Get Goosebumps
Oct 24, 2025 - The human body is full of 'left overs' that don't seem to serve any useful purpose, like the arrector pili muscles which control goosebumps.
https://nl.wikipedia.org/wiki/Musculus_arrector_pili
Musculus arrector pili - Wikipedia
musculuspiliwikipedia
https://pmc.ncbi.nlm.nih.gov/articles/PMC4158628/
Beyond Goosebumps: Does the Arrector Pili Muscle Have a Role in Hair Loss? - PMC
The arrector pili muscle (APM) consists of a small band of smooth muscle that connects the hair follicle to the connective tissue of the basement membrane. The...