A/P CH 11 - Muscular System Flashcards
Origin
The point of attachment of a muscle which remains stationary during movement, usually proximal
Insertion
the point of attachment of a muscle which is attached to the movable bone, usually distal
Reverse muscle action
when point of origin and insertion can change. I.E. the gluteus maximus with extension of the hip vs pulling the leg backwards
Length of muscle fiber vs force
longer muscle fiber - greater ROM
greater cross section - greater force
Types of muscle fiber arrangements
parallel, fusiform, circular, triangular or pennate
Prime mover / agonist
the muscle that contracts to create a movement or action
Antagonist
the muscle which stretches and yields to the effects of the prime mover
synergists
helper muscles
fixators
muscles that stabilize the origin of the prime mover, help the prime mover act efficiently
compartment
a group of skeletal muscles, associated blood vessels and associated nerves. All have a common function. Usually surrounded by connective tissue
Muscles of the head
originate in the fascia or bones of the skull, insert into the skin, move the skin not a joint with contraction, divided into 2 groups: act on the mouth, act on the eyes
Eye movement
extrinsic muscles move the eyeballs, means they originate outside of the eyeball, insert on the sclera
Muscles for the mandible
help in chewing and speech. 4 pairs
Muscles for the tongue
Also help with speech, both extrinsic and intrinsic muscles, extrinsic - move the entire tongue, intrinsic - alter the shape of the tongue
Muscles of the anterior neck
assist in deglutition (swallowing) and speech. these include the first muscles which are innervated by spinal nerves