Home
Flashcards
Preview
ch 11.txt
Home
Get App
Take Quiz
Create
How are muscles named
shape
size
location
relative position
# of heads
Action
Fiber direction
What happens when the muscle contracts?
muscle fibers shorten and when they shorten tension is produced.
Define Origin
anchor end of the muscle
attaches to bone that doesnt move
Define insertion
end of the muscle that is attached to the moving structure and is pulled toward the origin.
Where the action happens
Describe the Belly of the muscle
actual muscle tissue located between insertion and origin where contraction happens
Do longer or shorter fibers generate more force?
longer fibers are more powerful than shorter fibers
List the 6 types of fascicle arrangements
Parallel
Convergent
unipennate
bipennate
multipennate
circular
Describe parallel arrangement
parallel to long axis of muscle. Not strongest arrangement
but cant get good pwr w/ longer fibers
more fibers adds to strength
Describe convergent arrangement
Broad base of fibers that come together at a common attachement sight
example
: pectoral major or minor
Describe unipennate arrangement
fibers are short in relation to muscle length
fibers on one side of tendon on angle
example
: extensor digitorum
Describe bipennate arrangement
Fibers are short in relation to muscle length
fibers on both side of tendon on angle
looks similar to a feather
example
: rectus femoris
Describe Multipennate arrangement
fibers are short in relation to muscle length
arrangement of bipennate arrangements
like a bunch of feathers bound at base
example
: deltoid
Define Agonistic muscles
muscles that work together
Define prime mover
muscle in agonistic group that does the largest share of work
Define synergistic muscle
muscles that assist the prime mover
example
: to flex the elbow
Prime mover - brachalis
synergist - biceps brachii
synergist - brachioradials
Define antagonistic muscle
muscles having opposite actions
sd to oppose prime mover
What should the antagonist do when the prime mover is contracting?
nothing or relax
Define lever and associate with body
strait rod that moves on a fixed point called the fulcrum.
It allows for max work for any given amount of force applied.
long bones act as levers
Define fulcrum
Balance point for a lever
Where the action takes place
in body = joints
Define resistance
force opposing movement that comes from structure's weight and restrictions on structure
Define effort
force acting to promote movement. AKA applied force
in body it comes from muscles
Define leverage
the mechanical advantage gained by a lever
When will movement occur?
movement occurs when applied force/effort exceeds resistance
Describe 1st class lever
like a teeter totter - fulcrum is in middle
maximum range of movement and speed
few in body
ex. head nodding
Describe 2nd class lever
like a wheel barrel - fulcrum is wheel, load in barrel and Applied force is at end of handles when lifted
Max power
few in body
ex. found in ankle - heel lifts
Describe 3rd class lever
like food tongs or a hockey stick - fulcrum on one end, Applied force in middle and load on other end
good range of motion, power and speed
common lever in body
ex humerus and ulna/radius (elbow as fulcrum)
Describe 3rd class lever
Author
jen_scott09
ID
82924
Card Set
ch 11.txt
Description
chapter 11
Updated
2011-05-01T05:20:48Z
Show Answers
Home
Flashcards
Preview