Motion Will Occur in a Muscle When the ___ Supplied

Question

Motion will occur in a muscle when the ___ supplied exceeds the ___.
A) effort, load
B) resistance, lever
C) load, effort
D) load, resistance
E) lever, effort

Accepted Answer

This is known as the principle of muscle contraction, also known as the sliding filament theory. When the effort (force generated by the muscle) supplied by the myosin heads exceeds the load (resistance to movement), the actin filaments are pulled towards the center of the sarcomere, resulting in muscle contraction. The resistance and lever may play a role in the overall force required to move a load, but they are not directly related to muscle contraction.