Physiology 11th Edition Chapter 8
Muscular System
Tendons - ANS - Composed of dense fibrous connective tissue.
Binds muscle to the periosteum.
\Point of Insertion - ANS - more movable bony attachment of the muscle, is pulled toward the
origin
\Point of Origin - ANS - less movable bony attachment of the muscle
\Aponeurosis - ANS - flattened sheet-like tendons
Ex. on skull
\-sium - ANS - suffix meaning "muscular"
\Sarcolemma - ANS - Binds myofibrils (bunches of filaments) into a muscle fiber
\Endomysium - ANS - Surrounds muscle fibers
\Perimysium - ANS - Binds fascicles (bunches of fibers)
\Epimysium - ANS - covers muscle (bunches of fascicles)
\Fascia - ANS - Connective tissue that covers muscle and attaches it to the skin
\Actin - ANS - thin muscle filament that forms "I bands" in muscle striations
\Myosin - ANS - thick muscle filament that forms "A bands" in muscle striations
\Myofilaments or filaments - ANS - composed of actin and myosin
\Myofibrils - ANS - muscle fiber, is composed of myofilaments
\Muscle Fiber - ANS - bunches of myofibrils
\Fascicle - ANS - bunches of fibers
\Muscle - ANS - bunches of fascicles
\Threshold Stimulus - ANS - Minimum strength required to cause a muscle contraction
\All-or-None Contractions - ANS - Muscle contracts either minimally or not at all
\Motor Unit - ANS - single motor neuron and the 100-150 muscle fibers it controls
\Epinephrine - ANS - hormone that promotes an increase in produced force
\Isotonic Contraction - ANS - Shortening of muscle
Ex. bicep curl
\Isometric Contraction - ANS - Too much or not enough force to shorten muscle
Net force = Zero
Ex. pushing palms together
\Isokinetic - ANS - resistance throughout an entire range of motion
Ex. swimming
\Sarcomeres - ANS - Repeating pattern of units that appear as muscle striations.
-Consist of I-bands and A-bands
-Separated by "Z lines"
\I-bands - ANS - Actin filaments