Search results
Results From The WOW.Com Content Network
The arthropod exoskeleton is divided into different functional units, each comprising a series of grouped segments; such a group is called a tagma, and the tagmata are adapted to different functions in a given arthropod body. For example, tagmata of insects include the head, which is a fused capsule, the thorax as nearly a fixed capsule, and ...
A uniramous limb comprises a single series of segments attached end-to-end. A biramous limb, however, branches into two, and each branch consists of a series of segments attached end-to-end. The external branch (ramus) of the appendages of crustaceans is known as the exopod or exopodite, while the internal branch is known as the endopod or ...
A beetle leg. An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface appendages.
The strong, segmented limbs of arthropods eliminate the need for one of the coelom's main ancestral functions, as a hydrostatic skeleton, which muscles compress in order to change the animal's shape and thus enable it to move. Hence the coelom of the arthropod is reduced to small areas around the reproductive and excretory systems.
Discarded exoskeleton of dragonfly nymph Exoskeleton of cicada attached to a Tridax procumbens (colloquially known as the tridax daisy)An exoskeleton (from Greek έξω éxō "outer" [1] and σκελετός skeletós "skeleton" [2] [3]) is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs ...
The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an external skeleton . In order to keep growing, they must go through stages of moulting , a process by which they shed their exoskeleton to reveal a new one.
The development of distinct tagmata is believed to be a feature of the evolution of segmented animals, especially arthropods. In the ancestral arthropod, the body was made up of repeated segments, each with similar internal organs and appendages. One evolutionary trend is the grouping together of some segments into larger units, the tagmata.
From the embryonic stages, a layer of columnar or cuboidal epithelial cells gives rise to the external cuticle and an internal basement membrane. The majority of insect material is inside of the endocuticle. The cuticle provides muscular support and acts as a protective shield as the insect develops.