Muscle system part 2 - muscle mechanics

What are fasciles

Bundles of musle fibers

What do fascicle arrangement affect

Muscle’s power and range of motion

The longer the fiber, the greater the

range of motion

The greater of cross sectional area, the greater the

power

thickness

What are the five patterns of fascicle arrangement

parallel, fusiform, circular, triangular, pennate

Circular arrangement - fascicle pattern

Concentric rings around openings (eyes and mouth)

circular

What pattern are orbicularis oris, orbicularis oculi

circular

orbicularis oris (mouth)

orbicularis oculi (eye)

Convergent arrangement - fascicle pattern

Wide origin, narrow insertion like a fan / triangle

What fascicle arrangement is the pectoralis major

Convergent

Parallel arrangement - fascicle pattern

Fibers are parallel to long axis like a strap

Good range of motion, less force

What fascicle pattern is the sartorius

Parallel

Fusiform arrangement - fascicle pattern

Spindle shaped with parallel fibers (opposite of a hourglass) - fat in the middle narrow at the ends

Good range of motion, moderate force

What fascicle arrangement is bicep brachii

Fusiform

Pennate arrangement - fascicle patterns

Short fascicles attach obliquely (angularly) to tendon

Unipennate, bipennate, multipennate

Extensor digitorum longus - what pattern

Unipennate

Rectus femoris - what pattern

Bipennate

Deltoid - what pattern

Multipennate

Which fascicle arrangement generate the most force

Pennate

What do levers do

move heavier, farther, or faster

What are the 4 components of the lever system

Lever, Fulcrum, effort, load

Lever component of lever system

bone that moves

Fulcrum component of lever system

joint → pivot point that the bone moves on

Effort component of lever system

Force from muscle contraction applied to lever to move resistance

Load component of lever system

Resistance (bone, tissue, added weight) moved by effort

Which lever provides mechanical advantage

Power lever → load is closer to fulcrum than effort

Less effort can move large load (less effort, more strength, less speed)

Which lever provides mechanical disadvantage

Speed lever - load is farther from fulcrum than effort

Faster movement over large range of motion, less power

First class levers

E - F - L
Fulcrum in the middle

Which class lever

Head balancing on neck

First class

Second class lever

F - L - E

Load in middle

what class lever

Calves flexing to tip toe

Second class lever

Third class lever

L - E - F

Effort in the middle

What class lever

Bicep curl

Third class lever

Forceps, seesaw, wheel barrow - which goes into which class lever

Seesaw is first class (fulcrum in the middle)

Wheelbarrow is second class (load in the middle)

Forceps is third class (Effort in the middle)

Which class lever produces the most force with least effort

Second class with load in middle

What class muscle are most muscles in the body

third class levers