How Can Summation of Skeletal Muscle Twitches Occur If the Motor

question 48

Multiple Choice

How can summation of skeletal muscle twitches occur if the motor neuron's refractory period prevents multiple action potentials from being transmitted to the neuromuscular junction at the same time?

• A) The motor neuron's absolute refractory period is much shorter than the time it takes for calcium release and reuptake from the SR.
• B) The motor neuron's absolute refractory period is much longer than the time it takes for calcium release and reuptake from the SR.
• C) The motor neuron's absolute refractory period is much shorter than the muscle action potential.
• D) The motor neuron's absolute refractory period is much longer than the muscle action potential.

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Definitions:

Hammer

A tool consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object.

Anvil

A heavy iron block used in metalworking as a surface upon which metals can be hammered and shaped.

Auditory Cortex

The part of the brain that processes auditory information, located in the temporal lobe.

Temporal Lobe

A region of the cerebral cortex responsible for processing auditory information and is involved in memory and emotion.