CHAPTER 11 (REV 13) Flashcards
(56 cards)
What do the voluntarily controlled muscles of your body compose?
The muscular system
What is the attachment of a muscle’s tendon to the stationary bone called?
Origin
What is the attachment of the muscle’s other tend to the movable bone called?
Insertion
The origin is usually _____ and the insertion is _____
Proximal, Distal
The fleshy portion of the muscle between the tendons is called the _____?
Belly (Body)
When a muscle contracts, what are the main movements that occur called?
Actions
During specific movements of the body, the actions are reversed, therefore, the positions of the origin and insertion of a specific muscle are switched. What is this called?
Reverse Muscle Action (RMA)
In producing movement, bones act as ____ and joints function as _____ of these levers.
Levers, fulcrums
A rigid structure that can move around a fixed point. The rigid structure is called a what?
Lever
The fixed point that the lever can move around is called what? Symbolized by (F)
Fulcrum
A level is acted on at two different points by what two different forces?
- Effort (E) causes movement
- Load (resistance) which opposes movement.
If the load is closer to the fulcrum and the effort farther from the fulcrum, then only a relatively small effort is required to move a large load over a small distance. What is this called?
Mechanical Advantage
If the load is farther from the fulcrum and the effort is applied closer to the fulcrum, then a relatively large effort is required to move a small load (at a greater speed). What is this called?
Mechanical disadvantage
What are the three types of levers?
- First Class Lever: the fulcrum is between the effort and the load.
- Second Class Lever: the load is between the fulcrum and the effort.
- Third Class Lever: the effort is between the fulcrum and the load.
Skeletal muscle fibers (cells) within muscle are arranged in bundles known as what?
Fascicles
Five patterns that fascicles may form with respect to the tendons.
- Parallel
- Fusiform
- Circular
- Triangular
5: Pennate
Within opposing pairs, one muscle, contracts to cause an action while the other muscle stretches and yields to the effect of the other. These two are called what?
- Prime mover (agonist) - causes the action
- Antagonist (against) - stretches and yields
To prevent unwanted movements at intermediate joints or to otherwise aid the movement of the prime move, these muscles contract and stabilize.
Synergists
Muscles in a group that stabilize the origin of the prime move so that the prime mover can act more efficiently. These are called what?
Fixators
In the limbs, a group of skeletal muscles, associated blood vessels, and associated nerves which share a common function. This is called a what?
Compartment
Occipitofrontalis
Frontal Belly
Occipital Belly
Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in a look of surprise.
Closes and protrudes lips, as in kissing, compresses lips against teeth, and shapes lips during speech.
Orbicularis Oris
Zygomaticus Major
Draws angle of mouth superiorly and laterally, as in smiling.
Presses cheeks against teeth and lips, as in whistling, blowing and sucking; draws corner of mouth laterally, and assists in mastication by keeping food between the teeth.
Buccinator
