Skeletal Muscle Vocab Flashcards
collagen
fibrous insoluble protein found in the connective tissue, skin, ligaments, tendons, bone and cartilage
tendon
Strong connective tissue that attaches muscle to bone, densely packed collagen fibers, surrounded by sheaths
with blood vessels/nerves
ligaments
fibrous tissue that connects bone to bone
skeletal muscle
Voluntary, striated muscles attached to bones; composed of muscle fibers, connective tissue, nerves and blood vessels.
origin
attachment of a muscle that remains relatively fixed during
muscular contraction
insertion
The attachment of a muscle tendon to a moveable bone or the end opposite the origin
flexor
Muscle whose contraction bends a limb or other part of the body away from normal body position; joint angle becomes
more acute.
extensor
A muscle that serves to extend or straighten a part of the
body towards normal body position; joint angle becomes
greater.
sliding filament theory
Myosin protein filaments pull together Actin protein filaments. Calcium is required to allow actin and myosin to
interact and ATP is required for contraction.
muscle fiber
Single cell of the skeletal muscle; multinucleated, abundant mitochondria, modified cell membrane (sarcolemma), modified ER (Sarcoplasmic Reticulum)
myofibril
Proteins arranged in parallel bundles throughout muscle
fiber, organized into function units called sarcomeres; pro-
teins involved include actin/myosin and tropomyosin/troponin.
excitation
When action potential arrives at neuromuscular junction,
it travels throughout fiber and stimulates sarcoplasmic
reticulum to release Ca ions.
T tubules
Tube formed by protrusion of sarcolemma deep into cell interior, carries membrane impulse to myofibrils deep within the fiber.
Sarcoplasmic Reticulum
Wraps around each Myofibril, releases calcium to stimulate actin/myosin contraction, actively transports calcium
back in during relaxation of muscle fiber.
Acetylcholine
a neurotransmitter that, among its functions, triggers muscle contraction
