1.1.5.4　Muscles

The most common one in the skin is the arrector pili muscle，composed of slender smooth muscle fiber bundles，one end of which reaches the papillary layer of the dermis and the other end is inserted into the fiber sheath in the middle of the hair follicle.In addition，there are smooth muscles of the scrotum's sarcolemma and areola，as well as smooth muscles on the blood vessel wall.The muscle epithelial cells around sweat glands also function as smooth muscle.There are striated muscles in the facial skin，that is，mimetic muscle.(https://www.daowen.com)