Appendage
From The Art and Popular Culture Encyclopedia
Related e |
Featured: |
An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body.
In invertebrate biology, an appendage refers to any of the homologous body parts that may extend from a body segment, including antennae, mouthparts (including mandibles, maxillae and maxillipeds), gills, locomotor legs (pereiopods for walking, and pleopods for swimming), sexual organs (gonopods), and parts of the tail (uropods). Typically, each body segment carries one pair of appendages. An appendage which is modified to assist in feeding is known as a maxilliped or gnathopod.
In vertebrates, an appendage can refer to a locomotor part such as a tail, fins on a fish, limbs (legs, flippers or wings) on a tetrapod; exposed sex organ; defensive parts such as horns and antlers; or sensory organs such as auricles, proboscis (trunk and snout) and barbels.
Appendages may become uniramous, as in insects and centipedes, where each appendage comprises a single series of segments, or it may be biramous, as in many crustaceans, where each appendage branches into two sections. Triramous (branching into three) appendages are also possible.
See also