- published: 07 Mar 2015
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The cuticle forms the major part of the integument of the Arthropoda. It includes most of the material of the exoskeleton of the insects, Crustacea, Arachnida, and Myriapoda.
In arthropods, the integument, the external "skin", or "shell", is the product of a single layer of ectodermal epithelium. That layer is attached to the external or distal surface of the deepest layer, the non-cellular internal membrane of the integument. That non-cellular membrane is called the basement membrane. The layer of epithelium on the basement membrane produces the cuticle, which begins as a tough, flexible layer of chitin. Such thin, flexible chitin is the major structural part of the integument where flexibility is necessary, such as in bodily parts that must stretch to contain accumulated liquids, or that form joints between rigid parts of the exoskeleton. In other parts of the cuticle the function of the integument demands more rigid materials, such as armoured regions or the biting parts of the jaws, or where the exoskeleton forms the tubular limbs of most Arthropoda. To achieve such rigidity the outer chitin layer of the cuticle is impregnated, thickened, and reinforced with harder, more brittle materials such as sclerotinised proteins or calcite. This main chitinous layer of the cuticle is called the procuticle.
Beetle Armor Inspires Advanced Materials Last week, I told you how a sea sponge could lead to stronger buildings. Today, we have a beetle with an exocuticle, or exoskeleton, that could lead to much stronger, and lighter materials. A team from Northwestern's Engineering Department wants to know how insects, like the beetle, can have armor-like exoskeletons that should weigh it down, but are actually light enough so they can fly. Now, there is more than a million species of beetles, but the team studied the fig eater beetle, a field crop pest native to the western United States. Like all insects and crustaceans, its exoskeleton is composed of twisted plywood structures that help protect against predators. Fibers in this structure are bundles of chitin polymer chains wrapped with proteins....
Lyrics: Verse1: I want to free fall, and leave the city lights Go and kick it in the country, lead a simple life Watch the bugs search for food, in the tall wet grass And see the water roll off, cause epicuticles are wax The exocuticle is stiff and strong 'cause it's tanned It keeps insects safe 'cause there's danger across the land Bugs couldn't move if endocuticles were plastic But chitin and water make it tough and elastic When insects grow, they shed the shell they're in Molting starts when cuticles split from the skin Endocuticle sheds; exocuticle breaks down But first, the new one is secreted safe and sound And joints are like hinges; flexibility is key They need chitin and water, so the motion is free And the structure's dynamic, so water secretes When the stiffness is too h...
Biological Design: Creative Construct 3! Lyrics: Verse 1 Hey there Delilah, why you stuck in the city? Come and kick it in the country where the bugs are always busy Yea they're searching for food, where it's wet and grassy but water damage ain't a worry; epicuticles are waxy The exocuticle is tanned, stiff and strong With cross-linked proteins, water doesn't belong Bugs couldn't walk if endocuticles were plastic Chitin and water make it tough and elastic When insects grow, they shed the shell they're in Molting starts when cuticles split from the skin Endocuticle sheds; exocuticle breaks down Right after the new one is secreted safe and sound Around joints, movement is key Chitin and water keep it flexible and free When stiffness is too high, water secretes The cuticle's stiffness s...
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, tardigrades, and Cephalorhyncha. Since the cuticula of these animals often forms an inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae. After moulting, an arthropod is described as teneral, a callow; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a tanning process similar to that of the tanning of leather. It is during this short phase that the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Grow...
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