Muscle Physiology

narrow, tapered rod-shaped cells; non-striated, uninucleated fibers; involuntary

striated, tubular, branched uninucleated fibers; walls of the heart; involuntary

striated, tubular, multinucleated fibers; voluntary

capability of the muscle to respond to a stimulus

ability of a muscle to shorten and generate a pulling force

muscle can be stretched to their normal resting length and beyond to a limited degree

ability of the muscle to recoil to its original resting length

connective tissue covering group of fascicles

connective tissue covering the fascicles

connective tissue covering each of the muscle fibers

basic rod-like unit of a muscle fiber

cell membrane of muscle cell

endoplasmic reticulum of the muscle cell

invaginations of sarcolemma

portion of SR nearest the t-tubule; site of calcium release(contraction) and reaccumulation(relaxation)

composed of two terminal cisternae with t-tubule in between

cytoplasm of muscle cell

light band

dark band

defines boundary of sarcomere

light area present in the center of the sarcomere; has myosin thic filaments

center of sarcomere, contains proteins critical for organization and alighnment of the thick filaments

also known as connectin, large protein that binds thick myosin filaments to the Z line

extends along hte length of the thin filament and may participate in the regulation of the length of the thin filament; binds thin filaments to Z disc

connects the z line to the connective tissue

site for nebulin attachment

connects Z lines of 2 adjacent parallel sarcomeres

bundle of myosin proteins shaped like a double-headed golf club; connected to Z lines by titin

formed by aggregation of actin molecules

extends over the entire actin filament and cover myosin binding sites on actin molecules in the absence of calcium

binds/high affinity for calcium

high affinity for actin; facilitates inhibition of myosin binding to actin by tropomyosin

high/binds affinity for tropomyosin

has myosin binding site; composed of g-actin molecule

located at the end of the thin filament; may participate in setting the length of the thin filament

structural link between the subsarcolemmal cytoskeleton of the muscle and the extracellular matrix; stability

power stroke is
produced by:
results into: 

low affinity calcium-binding protein; helps accumulate calcium in the terminal cisternae

anchors calsequestrin near RYR; increases calcium buffering capacity at the site of calcium release

serves as a repid mobilizable reserve of energy-phosphate