CH. 10 Muscular System - Dr. Jones

agonist

prime mover

-producing specific movement ; when it contracts, flexion occurs in that specific area

antagonist

opposes or reverses particular movement

synergist

helps prime movers (assist agonist)

-adds extra force to same movement

-reduces unnecessary movement

fixators

immobilizes bone or muscle’s origin

origin

attachment point on the bone that moves the least

insertion

attachment point on the bone that moves the most

-flexes to origin point (moveable part goes to immovable part)

location

bone or body region which muscle is associated ex: temporalis (over temporal bone)

shape

describe the muscle’s distinctive shape ex: deltoid = triangle

size

muscle descriptor: maximus (largest), minimus (smallest), longus (long)

direction of muscle fibers and fascicles

where muscles run to.

-rectus (fiber run straight)

-transverse (fiber run right angle)

-oblique (fiber run at angles to imaginary defined axis)

number of origins

muscle descriptor: number of where muscle originate

ex: biceps (two origin) and triceps (three origin)

location of attachment

named according to point of origin and insertion (origin named first)

ex: sternocleidomastoid (attach to sternum and clavicle with insertion on mastoid process)

action

muscle name for movement they produce

ex: flexor or extensor

circular

fascicle arrangement:

fascicles arranged in concentric rings

ex: orbicularis oris

convergent

fascicle arrangement:

broad origin; fascicles converge toward single tendon insertion

ex: pectoralis major

parallel

fascicle arrangement:

fascicles parallel to long axis of strap-like muscle

ex: sartorius

fusiform

fascicle arrangement:

spindle-shaped muscles with parallel fibers

ex: biceps brachii

pennate

fascicle arrangement:

short fascicles attach obliquely to central tendon running length of muscle

ex: rectus femoris

unipennate

fascicle arrangement: form of pennate

fascicles attach only to ONE side of tendon

ex: extensor digitorum longus

bipennate

fascicle arrangement: form of pennate

fascicles insert from OPPOSITE sides of tendon

ex: rectus femoris

multipennate

fascicle arrangement: form of pennate

appear as feathers inserting into one tendon

ex: deltoid

zygomaticus major

smile

orbicularis oris

pucker

orbicularis occuli

blink

mentalis

pout

frontalis

raised eyebrows / wrinkled forehead

platysma

tense neck