 | Term | Definition |
| |
sarcomere |
the smallest functional unit of muscle tissue |
| |
myofibril |
a series of sarcomeres |
| |
muscle fiber |
a single muscle tissue cell |
| |
fascicle |
a bundle of muscle fibers |
| |
sliding filament theory |
theory of how muscles generate force |
| |
myosin proteins |
thick filaments |
| |
actin proteins |
thin filaments |
| |
titin |
maintains the position of the myosin in the center of the sarcomere & prevents the sarcomere from being pulled apart |
| |
active tension |
tension due to muscle contraction |
| |
passive tension |
tension due to muscle stretch |
| |
active insufficiency |
muscles aren't able to generate as much force in a shortened or lengthened position |
| |
passive insufficiency |
the motion of a joint may be limited by the length of a joint muscle because it's unable to stretch across both joints |
| |
strap, fusiform, rhomboidal, & triangular muscles |
types of muscles with fibers parallel to the tendon |
| |
unipennate, bipennate, & mutipennate muscles |
types of muscles with fibers oblique to the tendon (feather-like) |
| |
agonist |
main muscle used to produce a movement |
| |
antagonists |
muscles that oppose the movement of the agonist |
| |
synergists |
muscles that assist the action of the agonist |
| |
fixators |
muscles that stabilize the proximally to allow the agonist to work effectively |
| |
type I muscle fibers |
these muscle fibers are slow twitch, built for endurance, and are red |
| |
type IIa muscle fibers |
these muscle fibers are fast twitch, and can be trained to act like the other types |
| |
type IIb muscle fibers |
these muscle fibers are fast twitch, built for power, and are white |
| |
genetics |
fiber type is determined by this |
| |
muscle spindles |
lie parallel to the muscle fibers, detect changes in muscle length and the speed of the length change, they're responsible for deep tendon reflexes |
| |
golgi tendon organs |
located in the tendon, detect changes in tendon tension |
| |
paresis |
muscle weakness or partial paralysis |
| |
paralysis |
complete loss of muscle function |
| |
hemiplegia |
partial or complete loss of muscle function on 1 side of the body |
| |
paraplegia |
paralysis of all or some of the muscles in the trunk & lower extremities |
| |
tetraplegia/quadriplegia |
paralysis of the trunk & lower extremities & some or all of the upper extremities |
| |
atrophy |
loss of muscle mass due to lack of use or loss of innervation |
