Feathered skin of a chicken (HE): overview
The skin of birds is covered by feathers over most of the body but can be bare in specific regions, often the head and neck. In the feathered skin, feathers are not equally distributed but grow in definite patches or feather-tracts (pterylae) that are separated from each other by areas where no feathers grow, the apteria (apterylae).
The skin of birds consists of an epidermis, a dermis and a subcutis. Feather follicles are completely situated in the dermis. Smooth muscles (mm. pennati, mm. pennarum- NAA) attach to the follicle wall by elastic fibers and are arranged in a muscular network that connects adjacent follicles to each other.