Arrector pili muscles
bundles of smooth muscle fibres, attached to the deep part of the hair follicles, passing outward alongside the sebaceous glands to the papillary layer of the corium; they act to pull the hairs erect, causing goose bumps or goose flesh (cutis anserina).
Synonym: musculi arrectores pilorum, arrectores pilorum, erector muscles of hairs.
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