vilunväristysten
Vilunväristykset, commonly translated as "shivers" or "goosebumps," are a physiological reaction characterized by the sudden erection of hairs on the skin and a sensation of cold. This phenomenon is primarily caused by the activation of tiny muscles called arrector pili, which are attached to hair follicles. When these muscles contract, they pull the hair shafts upright, creating the characteristic bumpy appearance of the skin.
The contraction of arrector pili muscles is a reflex triggered by the sympathetic nervous system. This system
While the role in thermoregulation is less significant in modern humans due to our relative lack of