CH 10 Flashcards
muscle contraction causes…
body movements by pulling one bone or other structure toward another across a movable joint
muscle action
the movement accomplished when a muscle contracts
Each muscle has 2 points of attachment:
origin and insertion
origin
- fixed end (head) of the muscle
- less movable end: muscles can have more than one head (biceps brachii), usually the proximal or medial end of a muscle
insertion
- mobile end of the muscle
- end undergoing the greatest movement: usually the distal of lateral end of a muscle, muscles can insert on more than one structure
Muscle Structure: Belly
part of the muscle located between the origin and the insertion
tendons
long, cable-like structures that connect muscles to bones and other structures
aponeuroses
layers of flat sheet-like structures (broad tendons)
muscles are usually grouped so that…
the action of one muscle is opposed by that of another muscle or muscle group
agonist
- muscle that causes a certain movement
- example: biceps brachii (flexion)
antagonist
muscle that acts in opposition to the agonist
example: triceps brachii (extension)
muscle function in groups to…
accomplish specific movements
synergists
muscles that function together to produce movement
prime mover
the synergistic muscle that plays the major role in producing the movent
muscles are named according to their:
location size origin/insertion shape orientation of fasciculi number of heads function
