Skin: It is the covering of the entire external surface of the body. Pigments of skin are melanin, melanoid, carotene, hemoglobin, oxyhemoglobin. There are receptors in the skin. Appendages are nail, hair, sweat glands and sebaceous glands. Microscopic structure of thin and thick skin is different. Ear: Ear has three parts: external, middle and internal ear. External ear is made up of auricle or pinna and external acoustic meatus. Middle ear has ossicles and muscles. Inner ear has a bony and membranous labyrinth. Eye: Eye has outer fibrous (cornea, sclera), middle vascular (choroids, ciliary body, iris) and inner nervous coats (retina).