Biological Systems MCAT Practice Exam

In the context of muscle movement, what term describes muscles moving in the same direction?

1. Antagonistic

2. Synergistic

3. Isometric

4. Dynamic

The correct answer is: Synergistic

The term that describes muscles moving in the same direction is synergistic. Synergistic muscles work together to produce a movement, enhancing the overall effectiveness of that action. For instance, when you perform a bicep curl, the biceps brachii (the primary mover) works in conjunction with other muscles, such as the brachialis and brachioradialis, to facilitate the lifting of the forearm. This cooperation among muscles is crucial in many movements, allowing for smooth and coordinated actions by ensuring that different muscle groups support each other rather than oppose one another. In contrast, antagonistic muscles would work against each other; for example, when the biceps contract to lift a weight, the triceps relax to allow that movement. Isometric refers to muscle contractions where the muscle length does not change, while dynamic refers to movements involving changes in muscle length and joint angles, but does not specifically address the directional cooperation of muscles. Thus, synergistic is the most accurate term for muscles moving in the same direction.