Tsume (claw) - Tsume

Japanese: つめ(爪) - つめ

A plate-like or hook-like structure formed on the fingertips of reptiles, birds (only the hind legs), mammals, and insects. It resembles hair or reptilian scales in the sense that it is an appendage of keratinized skin of epidermal cells. It is divided into three types based on shape: the sole of primates, the claws of many mammals, birds, and reptiles, and the hooves of ungulates. Human nails belong to the sole of the nail, and the exposed part is called the nail body, and the base of the nail body buried in the skin is called the nail root. The lower layer of the nail is the nail bed, which consists of the epidermal germ layer and the dermis. The rear part of the nail bed is called the nail matrix, and the nail body is formed from here and pushed forward and upward. It grows about 0.1 mm per day. The part of the newly formed nail tissue that has not yet been fully keratinized is white and crescent-shaped, and is called the lunula.
→ Related topics Epidermis | Fingers

Source : Heibonsha Encyclopedia About MyPedia Information

Japanese:

爬虫(はちゅう)類，鳥類（後肢だけ），哺乳(ほにゅう)類および昆虫などの指先に形成される板状または鉤(かぎ)状物。表皮細胞の角質（ケラチン）化した皮膚の付属物という意味では毛や爬虫類の鱗に似る。形により霊長類のひらづめ（扁爪），多くの哺乳類，鳥類，爬虫類のかぎづめ（鉤爪）および有蹄類の蹄（ひづめ）の三つに分けられる。　ヒトのつめはひらづめに属し，露出している部分を爪(そう)体，皮膚の中に埋没している爪体の基部を爪根という。つめの下層は爪床で，表皮胚芽層と真皮からなる。爪床の後部を爪母といい，ここから爪体が作られ前上方に押し出される。１日に約0.1mmのびる。新生したつめの組織がまだ十分に角質化していない部分は白色の半月状で爪半月と呼ばれる。
→関連項目表皮｜指

出典　株式会社平凡社百科事典マイペディアについて　情報

<<: Claw mark - Tsumein

>>: Tsumura Betsuin