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9. Muscles and Muscle Tissue. Which of the following is not a prefix used to refer to muscle?. Mys Myo Sarco Lemma. Of the following muscle types, which is the only one subject to conscious control?. Smooth Skeletal Cardiac All of these muscle types are subject to conscious control.
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9 Muscles and Muscle Tissue
Which of the following is not a prefix used to refer to muscle? • Mys • Myo • Sarco • Lemma
Of the following muscle types, which is the only one subject to conscious control? • Smooth • Skeletal • Cardiac • All of these muscle types are subject to conscious control.
In order to receive a signal to contract, each skeletal muscle must be served by a(n) ________. • artery • nerve • vein • ligament
The functional unit of a muscle fiber is the __________. • sarcomere • myofibril • fascicle • myofilament
What is the major function of the sarcoplasmic reticulum? • Store sodium ions • Expel sodium ions from the cell • Expel calcium ions from the cell • Store calcium ions
What is the significance of the muscle fiber triad relationship? • The terminal cisternae subdivide the sarcolemma. • The T tubules bring calcium to the sarcoplasmic reticulum. • The sarcoplasmic reticulum transfers calcium to the T tubules. • The T tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum.
At the neuromuscular junction, the muscle contraction initiation event is ______. • a release of calcium ions from the sarcoplasmic reticulum • conduction of an electrical impulse down the T tubules • binding of acetylcholine to membrane receptors on the sarcolemma • sliding of actin and myosin filaments past each other
In a muscle fiber, the key intracellular event that stimulates muscle contraction is known as ________. • polarization • depolarization • repolarization • potential
During depolarization, the sarcolemma is most permeable to _______. • sodium ions • potassium ions • calcium ions • chloride ions
The time period between action potential initiation and mechanical activity of a muscle fiber is called the _________. • latent period • refractory period • action potential • excitation period
What is calcium’s function during muscle contraction? • Calcium binds to troponin, changing its shape and removing the blocking action of tropomyosin. • Calcium binds to troponin to prevent myosin from attaching to actin. • Calcium depolarizes the muscle fiber. • Calcium flows down the T tubules to stimulate the influx of sodium from the sarcoplasmic reticulum.
Corpses usually exhibit rigor mortis because __________. • ATP hydrolysis is stimulating myosin head attachment to actin • a lack of ATP hydrolysis prevents myosin head detachment from actin • calcium stores become deficient • sodium stores become deficient
Small precise movements are controlled by ______ motor units. • small • large • many • few
A muscle contraction increases in strength up to a point because ________. • stronger stimuli inhibit motor unit activation • recruitment occurs and more motor units respond to stronger stimuli • more calcium is available in the sarcoplasm • additional neurons begin stimulating each muscle fiber