Muscle Contraction Quiz

What is the smallest unit of muscle contraction?

• Twitch

• Tetanus

• Motor Unit

• Summation

How can the total force of muscle contraction be increased?

• By reducing the number of motor units

• By relaxing the muscle fibers

• By adding multiple twitches together

• By decreasing the frequency of stimulation

What happens when individual twitches occur so closely that they cannot be distinguished?

• Tetanus

• Twitch

• Relaxation

• Fatigue

What is the reason behind tetanus in muscle fibers?

• Increased motor unit activation

• Insufficient calcium reuptake

• Excessive calcium pumping

• Decreased action potential frequency

What is a motor unit?

• A single neuron

• A group of neurons supplying one muscle fiber

• A group of muscle fibers supplied by one neuron

• A single muscle fiber

What principle explains the activation of motor units from small to large?

• Summation principle

• Size principle

• Frequency principle

• Relaxation principle

Why are small motor units activated first during weak contractions?

• They are more easily stimulated by weak signals

• They generate more force

• They are larger in size

• They are less efficient

How does the size principle help in fine motor control?

• By reducing the number of active motor units

• By increasing the frequency of stimulation

• By allowing small adjustments in force

• By activating large motor units first

What is the role of asynchronous activation of motor units?

• To increase muscle fatigue

• To synchronize all motor units

• To maintain constant muscle force

• To decrease muscle tension

How is muscle force maintained when holding an object for a prolonged period?

• By reducing the number of active motor units

• By continuous contraction of the same motor units

• By alternating contraction of different motor units

• By increasing the frequency of stimulation