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Muscle-Building Workout and Diet


Most insect species have wings as adults and are able to fly. Unlike birds and bats, insect wings are not modified fore limbs, but are extensions of the cuticle of the meso- and meta-thoracic segments. These two thoracic segments also have prominent muscles used for generating the wingbeat Flight muscles of bats and birds attach directly to the wings, and pull the wings up and down. In insects, only dragonflies and damselflies have muscles attached directly to the wing and these muscles only produce the downstroke for the wingbeat. In all other flying insects, both the downstroke and upstroke of the wingbeat are produced in response to contractions by muscles that attach to the thoracic cuticle and not directly to the wing. The downstroke is produced by a set of dorsal, longitudinal muscles attached to phragma. Phragma are articular invaginations of the meso- and metathoracic segments. The upstroke is generated by a pair of dorso-ventral muscles attached to the top and bottom surfaces of the meso- and metathoracic segments. These indirect muscles act by undergoing rapid, antagonistic changes in tensions that produce alternating changes in the length and height of the thoracic segments. These alternating changes in the shapes of the segments cause the base of the wing to move in and out over a lateral fulcrum point that flips the wing into the upstroke and the downstroke for the wingbeat. Many insects species are able to move their wings rapidly and can fly at wing beats of 100 to 700 per second. By comparison, hummingbirds fly at approximately 50 wing beats per second. Muscles that attach directly to the base of the wing cause wing folding or may control the pitch and twisting of the wing in some species. you

13 thoughts on “9. Insect flight muscles

  1. This grass hopper is a poor example a flying insect though so extra info was need of which I have acquired from other sources..the grass hopper has air sacs along or in it abdomen I believe….

  2. This video is part of the morphology series. The grasshopper is used as the typical insect in the series. In all but Odonata, insect wings are extensions of the thoracic cuticle and the wingbeats are driven by the two sets of indirect flight muscles inserted on the thorax cuticle that distort the rigid thorax so the wings work like levers to flip in-and-out over fulcrum points. Air sacs lighten the insect and supply oxygen to the working muscle, but do not contribute directly to the wingbeat.

  3. @llkeeley Members of Odonata are interesting the speed at which they are able to move and turn is exrodanairy….also for speculations sake do you think intelligence in squid will continue to develop ever further?

  4. True. But this is part of a basic series showing the general structures and their functions for insects. Not actually a discussion of flight. It is only to illustrate that insects have a unique mechanism for moving their wings by distorting their thorax rather than the muscles pulling directly on the appendage.

  5. Good one. and thank God that YouTube is banned in China. Otherwise God knows how many shitty misleading videos there will be. I might not ever have the chance to come across this short but incredibly informative awesome video.

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