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Nail Anatomy
A nail is a protective plate characteristically found at the tip of the digit (anatomy), digits (fingers and toes) of all primates, corresponding to the claws in other tetrapod animals. Fingernails and toenails are made of a tough rigid protein called alpha-keratin, a polymer also found in the claws, hooves, and horn (anatomy), horns of vertebrates. Structure The nail consists of the nail plate, the nail matrix and the nail bed below it, and the grooves surrounding it. Parts of the nail The nail matrix is the active Tissue (biology), tissue (or Germ layer, germinal Matrix (biology), matrix) that generates cells. The cells harden as they move outward from the nail root to the nail plate. The nail matrix is also known as the ''matrix unguis'', keratogenous membrane, or onychostroma. It is the part of the nail bed that is beneath the nail and contains nerves, lymph, and blood vessels. The matrix produces cells that become the nail plate. The width and thickness of the nail p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integumentary System
The integumentary system is the set of organs forming the outermost layer of an animal's body. It comprises the skin and its appendages, which act as a physical barrier between the external environment and the internal environment that it serves to protect and maintain the body of the animal. Mainly it is the body's outer skin. The integumentary system includes skin, hair, scales, feathers, hooves, claws, and nails. It has a variety of additional functions: it may serve to maintain water balance, protect the deeper tissues, excrete wastes, and regulate body temperature, and is the attachment site for sensory receptors which detect pain, sensation, pressure, and temperature. Structure Skin The skin is one of the largest organs of the body. In humans, it accounts for about 12 to 15 percent of total body weight and covers 1.5 to 2 m2 of surface area. The skin (integument) is a composite organ, made up of at least two major layers of tissue: the epidermis and the dermis. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
