Question

In an isotonic contraction, the muscle ________?

1) changes in length and moves the "load"
2) does not change in length but increases tension
3) never converts pyruvate to lactate
4) rapidly resynthesizes creatine phosphate and ATP

Answer 1

In an isotonic contraction, the muscle changes in length to move a load, involving either concentric or eccentric contractions during lifting or lowering activities, respectively.

Step-by-step explanation:

In an isotonic contraction, involves the muscle shortening or lengthening while lifting or lowering a weight, respectively. There are two types of isotonic contractions:

• A concentric contraction occurs when a muscle shortens to move a load, such as lifting a hand weight, causing the biceps brachii to contract and the elbow angle to decrease.
• An eccentric contraction happens when a muscle lengthens while returning to its original position or controlling the descent of a load, as seen when lowering a hand weight in a slow and controlled manner.

Isotonic contractions are essential for movement, balance, and daily activities involving muscle tension and movement of objects.