part of part of capable of part of capable of part of temperature homeostasis male reproductive system scrotum reproductive structure dartos muscle dartos muscle of scrotum The tunica dartos acts to regulate the temperature of the testicles, which promotes spermatogenesis. It does this by expanding or contracting to wrinkle the scrotal skin. The wrinkled (rugose) appearance of the scrotum is due to this layer of fascia dartos tunic dartos layer of scrotum SCTID:279582001 the FMA class appears to belong here due to its synonyms. A dartos muscle that is part of a male reproductive system. FMA:27647 UBERON:0013719