Chapter 10 The Muscle System Flashcards
Define Origin:
Fixed or immovable point of attachment.
Define Insertion:
Attachment to the movable bone.
Define Prime Mover/Agonist:
Muscle that has the major responsibility for producing a specific movement.
Define Antagonist:
Muscles that oppose or reverse a specific movement.
Define Synergist:
Help prime movers by adding a little extra force of the same movement, or by reducing undesirable or unnecessary movements that might occur as the prime move contracts.
Define Fixator:
A synergist that immobilizes a bone, or a muscle’s origin so that the prime mover has a stable base on which to act.
Criteria on Which Skeletal Muscles are Named:
o Muscle Location o Muscle Shape o Muscle Size o Direction of Muscle Fibers o Number of Origins o Location of Attachments o Muscle Action
Muscle Patterns:
o Circular: Fascicles arranged in concentric rings.
o Parallel: Length of fascicles run parallel to the long axis of a muscle.
o Convergent: Fascicles converge toward a single tendon of insertion.
o Pennate: Fascicles are short and attach obliquely to a central tendon that runs the length of a muscle.
• Unipennate: Insert into only one side of the tendon.
• Bipennate: Insert into the tendon from opposite sides of the muscle’s grain.
• Multipennate: Many insertions side by side into one large tendon.
Define Lever:
Rigid Bar that moves on a fixed point.
Define Fulcrum:
The fixed point that the lever move on.
Define Effort:
Applied force of Levers and Fulcrums that is used to move against resistance.
Define Load:
Force of Resistance.
Define Mechanical Advantage:
Power Lever. Move a larger force.
Define Mechanical Disadvantage:
Speed Lever. Move a force more quickly.
Define First Class Lever:
- Effort is applied at one end of the lever and the load is at the other, with the fulcrum in between.
- Can be either a Mechanical advantage or disadvantage.
