The head and neck is covered in skin and its appendages, termed the integumentary system. The integumentary system consists of the skin, hooves, hair, and glands. These include the urinary system, female reproductive system, and integumentary system. Some scutes contain a single pore known as an integumentary sense organ. The three types of nephridia are&colon; integumentary, septal, and pharyngeal. Each of the dorsal spines is covered in an individual integumentary sheet. Scales are generally classified as part of an organism's integumentary system. The two main integumentary muscles of a cat are the "platysma" and the "cutaneous maximus". The integumentary system includes hair, scales, feathers, hooves, and nails. Aphaeomelanism is the abnormal absence of phaeomelanin from the integumentary system and/or eyes. The integumentary system has multiple roles in maintaining the body's equilibrium. Many substances can cause an allergic reaction when in contact with the human integumentary system. It has yet to be determined why such an integumentary change might have occurred. Integumentary sensory organs are present on the head and body scalation. "Longisquama" is characterized by distinctive integumentary structures along its back.