Tubercle

In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to. In the case of certain orchids and cacti, it denotes a round nodule, small eminence, or warty outgrowth found on the lip. They are also known as podaria (singular podarium). When referring to some members of the pea family, it is used to refer to the wart-like excrescences that are found on the roots. In mycology, a tubercle is used to refer to a mass of hyphae from which a mushroom is made. When it is used in relation to certain dorid nudibranchs such as Peltodoris nobilis, it means the nodules on the dorsum of the animal. The tubercles in nudibranchs can present themselves in different ways: each tubercle in a single, rounded, conical or angular form, in a compound form of 2 or more levels, tubercles in amalgamated clusters or as tubercles forming, or joined by a ridge. Tubercles found on the leading edge of humpback whale's flippers were demonstrated to improve fluid flow over the flipper's surface, exhibiting the tubercle effect of fluid dynamics. In dinosaurs, a tubercle is a general term for the scales seen in skin impressions. In duck-billed dinosaurs, for example, three main types of tubercles are defined: small tubercles with no definite arrangement (ground tubercles); larger, polygonal tubercles (pavement tubercles) up to 1 cm (0.4 in) in diameter, which are grouped into clusters separated by ground tubercles; and limpet-shaped conical scutes. Within the human body, there are numerous sites where tubercles develop. On bones, they are usually eminences used for muscle connections. Larger tubercles are also known as tuberosities. Tubercles are usually found behind the last molar in the upper jaw, covered by the gum. Surgery can be done to make tubercles less prominent.