And Answers
T tubule narrow tubes that are continuous with the sarcolemma and extend into the
sarcoplasm
Sarcoplasmic Organelle of the muscle fiber that stores calcium.
Reticulum a network or mesh of fibrils, fibers or filaments
Myofibril tightly packed filament bundles found within skeletal muscle fibers
Sarcomere a structural unit of a myofibril in striated muscle, consisting of a dark band and
the nearer half of each adjacent pale band.
Z line A dark thin protein band to which actin filaments are attached in a striated muscle
fiber, marking the boundaries between adjacent sarcomeres.
I band a light band composed of thin filaments only
, Ch 9 muscular system ecpi review Questions
And Answers
A band dark area; extends length of the thick filaments
H zone The region at the center of an A band of a sarcomere that is made up of myosin
only. The —zone gets shorter (and may disappear) during muscle contraction.
Acetylcholine A neurotransmitter that enables learning and memory and also triggers
muscle contraction
Acetylcholinesterase the enzyme that breaks down acetylcholine in the synaptic cleft
Motor end plate the flattened end of a motor neuron that transmits neural impulses to a
muscle
Troponin regulatory protein that binds to actin, tropomyosin, and calcium
Tropomyosin a protein involved in muscle contraction. It is related to myosin and occurs
together with troponin in the thin filaments of muscle tissue.