Chapter 9 Muscle Physiology Lab Questions

Which of the following situations delay the development of muscle fatigue the longest? A. Repetitive stimulation of a muscle B. Consistent interruptions of muscle stimulation C. Alternating sprints with up-hill jogging D. High intensity exercise E. Prolonged muscle contraction

B. Consistent interruptions of muscle stimulation

Which of the following occurs if the load attempted is equal to or greater than the force generated by muscle? A. Isotonic muscle contraction occurs B. Isometric muscle contraction occurs C. The muscle shortens D. The muscle lengthens

B. Isometric muscle contraction occurs.

Which of the following molecules is NOT thought to accumulate during muscle fatigue? A. ADP B. lactic acid C. ATP D. inorganic phosphate

ATP

For a weight to be lifted, which of the following must occur? A. An isotonic muscle contraction with a force less than the load B. An isotonic muscle contraction with a force greater than the load C. An isometric muscle contraction with a force greater than the load D. An isometric muscle contraction with a force less than the load

B. An isotonic muscle contraction with a force greater than the load.

The resting length of the muscle __________. A. Describes the length of the muscle during contraction B. occurs when the muscle is relaxed C. Occurs when peak tension develops D. Describes the muscle during stimulation

B. Occurs when the muscle is relaxed

Which of the following is NOT a phase of a muscle twitch? A. Latent phase B. Relaxation phase C. Contraction phase D. Shortening phase

D. shortening phase

When wave summation occurs, _______. A. The muscle fiber has received a single stimulus event B. The muscle force generated decreases C. Individual muscle twitches are separated D. The muscle force generated increases

D. the muscle force generated increases

Which of the following is generated when cross-bridges form between actin and myosin? A. ATP B. Active force and ATP C. active force and passive force D. Passive force E. Active force

E. Active force

Why does wave summation occur? A. Muscle fibers are partially contracted when the next stimulus arrives B. Muscle fibers have been allowed to fully relax C. Muscle twitches are not yet overlapping D. A large amount of time elapses between stimulations

A. Muscle fibers are partially contracted when the next stimulus arrives.

Which of the following occurs during the latent period of isotonic concentric contraction? A. Muscle tension is produced, and the weight will not move B. Muscle tension is produced, and the weight will move C. Muscle tension is not produced, and the weight will move D. Muscle tension is not produced, and the weight will not move

A. Muscle tension is produced, and the weight will not move

Which of the following is true of the maximum stimulus frequency? A. No greater muscle force can be generated and the muscle has reached maximal tetanus tension B. Muscle force will decrease C. Muscle has reached maximal tetanic tension D. No greater muscle force can be generated and muscle force will decrease E. No greater muscle force can be generated

A. No greater muscle force can be generated and the muscle has reached maximal tetanic tension.

A motor unit is defined as__________ A. The axon terminals of a single motor unit and all of the muscle fibers it stimulates B. A single muscle fiber and all its axons C. A nerve and a muscle D. A single neuron and a single muscle fiber

A. The axon terminals of a single motor neuron and all of the muscle fibers that it stimulates

Which of the following does NOT describe tetanus? A. The muscle relaxes fully between contractions B. The maximum force produced has reached a plateau C. It can be fused D. It can be unfused

A. The muscle relaxes fully between contractions.

Which of the following terms are NOT used interchangeably? A. Motor unit- motor neuron B. Muscle cell- muscle fiber C. Muscle tension- muscle force D. In vivo- in the body/ the living

A. motor unit - motor neuron

Where does the acetylcholine that stimulates muscle contraction bind? A. Receptors in the motor end plate B. Receptors in the sarcoplasmic reticulum C. Receptors in the axon terminal D. Receptors in troponin

A. receptors in the motor end plate

NO force is generated during which of the following? A. The latent period B. The relaxation phase C. A muscle twitch D. The contraction phase

A. the latent period

when the frequency of stimulation of a muscle is great enough, _____________ A. Wave summation results and muscle twitches overlap B. Full relaxation of muscle occurs C. Wave summation results D. Full relaxation of the muscle occurs and wave summation results E. Muscle twitches overlap

A. wave summation results and muscle twitches overlap

Which of the following describes the relationship between length and tension? A. As the muscles resting length increases, the active force will decrease. B. The active force can increase or decrease, depending on the starting testing length of the muscle C. As the muscles resting length increases, the active force will increase D. as the muscles resting length decreases, the active force will decrease.

B. The active force can increase or decrease, depending on the starting resting length of the muscle.

Which of the following occurs during isotonic concentric contraction? A. The length of the muscle increases and decreases with contraction B. The length of the muscle decreases with contraction C. The length of the muscle increases with contraction D. The length of the muscle stays the same

B. The length of the muscle decreases with contraction.

Treppe is the phenomenon that results in _______. A. An increase in the stimulation frequency B. A progressive increase in the force generated with repetitive stimulation C. Motor unit recruitment D. Maximal force production by a skeletal muscle

B. a progressive increase in the force generated with repetitive stimulation

Muscle twitches overlap with________. A. Threshold voltage applied B. Unfused tetanus only C. Both fused and unfused tetanus D. Fused tetanus only

C. Both fused and unfused tetanus.

Which of the following occurs during the contraction phase? A. Acetylcholine binds to the sarcolemma B. Ca2+ release from the sarcoplasmic reticulum is blocked C. Cross-bridge cycling is taking place D. The sarcomeres are increasing in length

C. Cross-bridge cycling is taking place.

Which of the following would result in fused or unfused tetanus compared to a single muscle twitch? A. Decreasing the stimulus frequency B. Threshold stimulus and stimuli C. Increasing he stimulus frequency D. Decreasing the stimulus frequency or increasing the stimulus frequency.

C. Increasing the stimulus frequency

The speed of muscle contraction is called the __________. A. Contraction velocity B. Twitch velocity C. Shortening velocity D. Isometric velocity

C. Shortening velocity

When acetylcholine binds to its receptor, it results in______________ A. A graded depolarization B. A change in ion permeability C. The end plate potential, a graded potential, and a change in ion permeability D. The end plate potential

C. The end plate potential, a graded depolarization, and a change in ion permeability

Which of the following describes the relaxation phase? A. The sarcomeres are decreasing in length, and the force generated decreases B. The sarcomeres are decreasing in length, and the force generated increases C. The sarcomeres are increasing in length, and the force generated decreases D. The sarcomeres are increasing in length, and he force generated increases

C. The sarcomeres are increasing in length, and the force generated decreases.

Which of the following is matched correctly? A. Incomplete tetanus- fused tetanus B. Complete tetanus- unfused tetanus C. Complete tetanus - fused tetanus D. Incomplete tetanus- fatigue

C. complete tetanus - fused tetanus

During muscle fatigue, the _______________decreases. A. Number of muscle fibers B. Rest period C. Force of contraction D. Stimulus frequency

C. force of contraction

Which of the following occurs during the latent period of muscle contraction? A. Acetylcholine is released at the axon terminal and an action potential is generated B. An action potential is generated C. Acetylcholine is released at the axon terminal D. Calcium is released from the sarcoplasmic reticulum

D. Calcium is released from the sarcoplasmic reticulum

What is the minimum voltage needed to generate active force in the skeletal muscle? A. Contraction voltage B. Recruitment voltage C. Stimulus voltage D. Threshold voltage

D. Threshold voltage

Which of the following can trigger a muscle twitch? A. Release of acetylcholine B. Release of calcium from the sarcolemma C. Electrical stimulation D. Release of acetylcholine or electrical stimulation E. Release of acetylcholine or release of calcium from the sarcolemma

D. release of acetylcholine or electrical stimulation

Which of the following is proportional to the amount of tension produced by skeletal muscle?

The number of motor units activated