Ch 10 Flashcards
an alternate name for a skeletal muscle
muscle fibers
a property of a cell in which it is responsive in the presence of various stimuli
excitable
a property of a cell by which it can be stretched without sustaining damage
distensible
a property of a cell by which it will return to its resting length after it’s been stretched
elasticity
the cytoplasm of a muscle fiber
sarcoplasm
the plasma membrane of a muscle fiber
sarcolemma
long, cylindrical organelles composed of muscle protein in a muscle fiber
myofibrils
the specialized smooth endoplasmic reticulum of a muscle fiber that stores calcium ion
sarcoplasmic reticulum
hollow inward extensions of a muscle fiber sarcolemma that surround myofibrils; filled with extracellular fluid
transverse tubules (t-tubules)
enlarged regions of the sarcoplasmic reticulum where it contacts t-tubules
terminal cisternae
a t-tubules and two adjacent terminal cisternae in a muscle fiber
triad
muscle protein that make up myofibril in a muscle fiber
myofilaments
a myofilament composed of many molecules of the protein myosin
thick filament
a clube shaped contractile protein found in a muscle fibers and cells that are motile
myosin
a myofilament composed of molecules of the protein actin, troponin, and tropomyosin
thin filament
a bead shaped contractile protein found in muscle fibers and motile cells
actin
a filamentous regulatory protein that covers the active sites of actin subunits in a thin filament
tropomyosin
a regulatory protein with three subunits that binds tropomyosin and calcium ions in a thin filament
troponin
a myofilament that consist of the structural protein titin
elastic filament
the component of the sarcomere that appears lighter because it only contains thin filaments
I bands
the component of the sarcomere that appears darker because it contains thick filaments and areas in which the thick and thin filaments overlap
A bands
the components of the sarcomere that contains structural proteins to which thin and elastic filaments attach
Z disc
the functional unit of muscle contraction; consists of an area of the myofibril from one z-disc to the next z-disc
sarcomere
the mechanism of contraction of a muscle cell in which thin and thick filaments slide past one another while generating tension
sliding-filament mechanism
the study of electrical changes in the body’s cells and the physiological processes that accompany these changes
electrophysiology
