Muscular Contraction Review

During the resting phase of a muscle contraction:

• No muscle control or tension exists

• Some cross bridge overlap exists for postural control; otherwise, no muscle tension

• Cross bridge overlap causes increased muscle tension

During a concentric muscle contraction:

• The sarcomere is shortening as the H and I zone increase in size

• The sarcomere is shortening as the H and I zone decrease in size

• The sarcomere is lengthening as the A band remains the same

Without additional presence of ATP, the following will occur:

• Actin head will remain attached to myosin tail, the cross bridge will continue to be formed

• Myosin head will release from actin fiber, the cross bridge will discontinue to be formed

• Myosin head will remain attached to actin fiber, the cross bridge will continue to be formed

During an eccentric muscle contraction:

• The sarcomere is lengthening as the A band remains the same

• The sarcomere is shortening as the A band remains the same

• The sarcomere is lengthening as the H and I zone decrease

ATP stands for:

• Adenosine Triphasic

• Adrenaline Triphosphate

• Adenosine Triphosphate

The following is the correct order for phases of the sliding filament theory:

• Resting, excitation-contraction, contraction, relaxation, recharge

• Recharge, excitation-contraction, contraction, resting, relaxation

• Resting, excitation-contraction, contraction, recharge, relaxation

During the relaxation phase of a muscle contraction:

• Nerve stimulation ceases and calcium returns to the sarcoplasmic reticulum

• Nerve stimulation ceases and acetylcholine returns to the t-tubules

• Nerve stimulation ceases and calcium returns to the neuromuscular junction

During the excitation-contraction phase of a muscle contraction,

• Calcium binds to tropomyosin, opening the cross-bridge binding site

• Calcium binds to troponin, opening the cross-bridge binding site

• Calcium binds to actin, opening the cross-bridge binding site

The total amount of force produced by a muscle at the cellular level is determined by:

• ATP production and energy systems

• Total amount of activated cross bridges

• Total amount of calcium releases

Hydrolysis of ATP is the process of

• Adding water to ATP and results in ADP, phosphate and release of energy

• Taking away water from ATP to gain ADP, phosphate and release of energy

• Adding water to ADP and results in ATP, phosphate and release of energy