5.22 Direct and Indirect flight muscles Flashcards
How do bee’s muscles work?
Muscles in bees are similar to those found in all animals, as they can contract and pull on hard structures and relax to return to their original shape.
What are the indirect flight muscles in bees?
The indirect flight muscles in bees include the depressor and elevator muscles, which lower or raise the wings respectively.
Antagonistic pairs of muscles that work opposite to each other, such as the biceps and triceps in humans (When the biceps contract and the triceps relax, the elbow is bent. When the triceps contract and the biceps relax, the elbow is straightened).
Why are they called indirect muscles?
They are called indirect muscles because they are not attached to the wings; their action deforms the thorax, causing wing movement.
Where are the first set of indirect muscles located?
The first set of indirect muscles are found in thoracic segments T2 and T3 and are attached to the inner surface of the upper and lower thoracic segments.
What happens when dorsoventral muscles contract?
When dorsoventral muscles contract, they pull the upper and lower parts of the thorax closer together, elevating the wings.
What are longitudinal muscles?
Longitudinal muscles are found in the second thoracic segment and run from the upper front to the lower back of the segment.
What is the function of longitudinal muscles?
When longitudinal muscles contract, the notum forms a domed shape, lowering or depressing the wings.
What movement do the wings make when flying?
The wings make a figure of eight movement when flying, caused by the direct muscles.
What are direct muscles?
Direct muscles are attached to the sclerites at the base of each wing and are used to articulate the wings for fine-tuning flight.
How do bees use their flight muscles when not flying?
The wings uncouple from the muscles or thorax connections, and bees rapidly contract and relax their flight muscles to keep the hive and brood nest warm, similar to shivering in humans.
What dual role do indirect muscles play?
Indirect muscles have a dual role in providing power for flight and generating heat in the hive.
How do direct flight muscles work?
Direct flight muscles achieve both the up and downstrokes by being attached directly to sclerites at the base of each wing. One muscle contracts to pivot the wing upwards, while another muscle moves the wing downwards. These muscles work in tandem to generate lift and allow flight.
What is the role of indirect flight muscles?
Indirect flight muscles are attached to ridges within the thoracic exoskeleton, causing wing movement through changes in thorax shape rather than direct attachment to the wings. They consist of dorsoventral muscles for the upstroke and dorsal longitudinal muscles for the downstroke.
What are the two groups of indirect flight muscles?
The two groups are dorsoventral muscles, which generate the upstroke, and dorsal longitudinal muscles, which create the downstroke.
How do dorsoventral muscles function?
Dorsoventral muscles contract to deform the thorax shape, pulling the notum downwards, which forces the wing joint down and wingtips upwards.
What is the function of dorsal longitudinal muscles?
Dorsal longitudinal muscles contract to bow the notum upwards, forcing the wing joint to move upwards and bringing the wingtips down.
How is energy conserved during insect flight?
Energy is conserved as elastic components of the cuticle store and release energy during flight, minimizing energetic inputs and ensuring efficiency.
What role does resilin play in insect flight?
Resilin is a protein that helps store energy from wing momentum in elastic elements of the cuticle, which is released during the opposing stroke.
What are the three types of wing movements during flight?
The three types of movements are vertical flapping for lift, rotation around the base for pitch control, and wing flexing for finer flight control.
What is the significance of the figure eight wing pattern?
The figure eight pattern allows for better control of air movement around the wings, influencing the force and power produced during flight.
What are synchronous and asynchronous muscles?
Synchronous muscles produce one contraction cycle per nerve impulse, while asynchronous muscles can produce multiple contraction cycles from a single impulse, allowing for rapid wing beat frequencies.
How do asynchronous flight muscles function in derived neopteran insects?
Asynchronous flight muscles contract automatically when stretched beyond a threshold, requiring only a single nerve impulse to initiate flight.
