Flashcards in Muscular System Deck (42)
Most muscles cross ______ ______, and are usually attached to articulating bones.
The origin of the muscle is usually _______ and the insertion of the muscle is usually _______.
One bone remains ______ while the other bone is ______.
The muscle origin is located on the _______ bone while the insertion is usually on the _______ bone.
What is the fleshy portion of the muscle between tendons?
Belly or Body
What is a lever?
A rigid structure that can move around a fixed point.
What is a fixed point in the lever system called?
What is the effort arm?
Causes the movement (muscular contraction)
What opposes the movement?
Load or resistance
When does motion occur?
When the effort applied to the bone at the insertion exceeds the load.
When the load is _______ to the fulcrum and the effort is ______ from the fulcrum. This is called mechanical advantage.
When the load is ________ from the fulcrum and the effort is applied _______ to the fulcrum, this is called mechanical disadvantage.
A first class lever is when the fulcrum is _______ the effort and the load.
A second class lever is when the fulcrum is between the fulcrum and the ______.
A third class lever is when the ______ is between the fulcrum and the load.
What is the most common lever system in the musculoskeletal system?
________ _______ affects a muscle's power and range of motion.
The power of the muscle depends on what?
The total cross-sectional area
What is it when the tension remains constant as muscle length decreases or increases?
What are isotonic contractions used for?
Body movements and for moving objects.
What is a concentric contraction?
When the muscle shortens and produces movement to reduce the angle at a joint.
What is an eccentric contraction?
When the muscle lengthens during a contraction.
Example; lower the book to the table.
What is it called when a muscle does not change length?
What is an isometric contraction?
When tension increases greatly without a change in muscle length because the tension generated is not enough to exceed the resistance of the object to be moved
What is another name for the prime mover?
What is an antagonist?
The muscle that opposes the action of the prime mover, relaxes muscle.
The biceps and triceps are _______ ______.
What is a synergist?
The muscles that contract and stabilize the intermediate joints to prevent unwanted movements.
What is a fixator?
The muscles that stabilize the origin of the prime mover so that the prime mover can act efficiently.