The skin is a complex organ system consisting of three major layers of tissue, plus assorted accessory organs. The three major layers of the skin are the epidermis, dermis and hypodermis.
The innermost layer, the hypodermis, consists of fat and loose connective tissue to insulate the body and to bind the more superficial layers of the skin to the underlying tissue.

The dermis is composed of denser connective tissue. It contains many blood vessels and nerves, as well as accessory organs of the skin. These accessory organs include the sudoriferous (sweat) glands, the sebaceous (oil) glands and the hair follicles. At the border of the dermis and epidermis are many pigmented cells called melanocytes. These cells produce a dark pigment called melanin which is deposited in surrounding cells and so gives our skin its colour.

The epidermis is the most superficial layer of the skin. The fine structure of the epidermis may differ from place to place over the surface of the body. It may contain up to five histologically distinct layers of tissue. These are the stratum germinativum, which is immediately above the dermis and which contains the reproductive cells of the skin. New daughter cells produced in the stratum germinativum move towards the surface as they mature, and so, over the course of time, successively contribute to each of the more superficial layers of the epidermis. Immediately above the stratum germinativum is the stratum spinosum. The cells of this layer are linked together by tight junctions which in histological preparations give the cells a spiny appearance. The stratum granulosum is a relatively thin layer composed of dark, dying cells. On the soles of the feet and the palms of the hand, there is a yellowish layer of cells called the stratum lucidum. Immediately above the stratum granulosum is the stratum corneum, composed of dead, flattened cells.

Despite normally being very thin, the stratum corneum is quite tough and so protects the skin against penetration. The surface of the stratum corneum is also relatively acidic in most places, and so prevents the growth of many kinds of germs.

English - Japanese Glossary 

skin: 皮膚 (hifu); epidermis: 表皮 (hyouhi); stratum corneum: 角質層 (kakushitsusou); stratum lucidum: stratum granulosum: か粒層 (karyuusou); stratum spinosum: 有きょく層 (yuukyokusou); stratum germinativum: 基底層 (kiteisou); melanocytes: メラニン細胞 (meraninsaibou); dermis: 真皮 (shinpi); hypodermis: 皮下 (hika); stratum corneum: hair: 毛幹 (moukan); hair follicle: 毛嚢 (mounou); sebaceous gland: 皮脂腺 (hishisen); arrector pili muscle: 立毛筋(ritsumoukin); sudoriferous gland: 汗腺 (kansen); macule: 斑点 (hanten); papule: 丘疹 (kyuushin); vesicle: 小嚢 (shounou)

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