Question

bio - 201 topic 4: skeletal and smooth muscle
practice it
what happens when a muscle is fatigued?
it becomes stronger due to increased blood flow.
it becomes less flexible due to increased blood flow.
it is unable to contract efficiently due to a depletion of atp.
it is unable to contract efficiently due to a buildup of atp.
it contracts more efficiently due to an increase in atp.

Explanation:

Muscle contraction requires ATP. When fatigued, ATP is depleted, hindering efficient contraction. Increased blood - flow doesn't make fatigued muscles stronger, and ATP buildup isn't related to muscle fatigue in this way.

Answer:

It is unable to contract efficiently due to a depletion of ATP.