Unit 2 Muscles Flashcards
Aggregate muscle action
muscles work in groups rather than independently to achieve a given joint motion
Muscles named due to
Visual appearance
location
Function
Shape & fiber arrangement affects:
Muscle ability to exert force
range through it can exert force
Cross section diameter
factor in muscle ability to exert force
greater cross section=greater force exertion
2 types fo fiber arrangement
Parallel & pennate
divided by shapes
Parallel Muslce
arranged parallet to lenght of muscle
greater ROM than pennate fibers
Parallel shapes
Flat Fusiform Strap Radiate Circular/Sphincter
Flat muscle
rectus abdominus
Fusiform Muscle
central belly, tapers to tendons on ends
Ex. brachialis, bicep brachii
Strap muscle
sartorius
radiate muscle
combined arraengment of flat and fusiform
EX. Pectoralis major
Circular/Sphincter muscle
orbicularis oris
Pennate muscles
shorter fibers
arranged like a feather across tendon
increasd cross section=increased power
Unipenate muscle
run obliquely from one side only
Ex. biceps femoris
Bipennate Muscle
fiber runs obliquely on both sides of tendon
Ex.rectus femoris
Multipennate muscle
fibers run diagnolly along tendon
Ex.Deltoid
Strongest Contraction
Bipennate & Unipennate
Skeletal muscle tissue properties
Irritability/excitability
Contractility
Extensibility
Elasticity
Irritability/Excitability
Property of muscle being sensitive or responsive to stimuli
Ex. electrical
Contractility
ability of muscle to contract
Extensibility
ability of muscle to be stretched beyond normal length
Elasticity
ability of muscle to return to normal length
Innervation
segment of nervous system that provides stimlus to muscle fibers in specific area
Amplitude
range of muscle fiber length between max and min.
Gaster(belly or body)
the meaty part of muscle that increase in diameter
Fascia
Sheet of fibrous connective tissue
retinaculum
retains tendons close to body
origin
attachment closer to midline
Insertion
attachement farther away form midline
Contraction
Tension is developed in muscle due to stimulus
Passive muscle contraction
No joints move
Agonist muscle
primary movers
Antagonist muscle
act in opposition of agonist muscle
Stabilizers
surround joint or body part to stabilize area
Synergist
assist in action of agonists
Active insufficiency
muscle shorted to point that it cannot maintain tension
Passivley insufficiency
opposing muscle becomes stretched to where it cant allow movement
Palpation
Using sense of touch to examine muscle
