A muscle that assists an agonist by causing a like movement or by stabilizing a joint over which an agonist acts is a(n) a. antagonist, b. prime mover, c. synergist, d. agonist.

Verified step by step guidance

1. Understand the role of each term: An agonist is the primary muscle responsible for a movement, while an antagonist opposes the movement of the agonist.
2. Recognize that a prime mover is another term for an agonist, emphasizing its role as the main muscle executing the movement.
3. Identify that a synergist is a muscle that assists the agonist by either adding extra force to the movement or by reducing unnecessary movement.
4. Consider the function of stabilizing a joint: A synergist can stabilize a joint to allow the agonist to work more effectively.
5. Conclude that the muscle described in the problem, which assists an agonist, is best defined as a synergist.

Key Concepts

Agonist

An agonist is a muscle that is primarily responsible for producing a specific movement. It contracts to create the desired action, such as flexing the arm during a bicep curl. Understanding the role of the agonist is crucial for identifying how muscles work together during movement.

Synergist

A synergist is a muscle that assists the agonist in performing a movement. It can help by stabilizing a joint or by contributing additional force to the action. Recognizing the function of synergists is essential for understanding how multiple muscles coordinate to achieve smooth and effective movements.

Antagonist

An antagonist is a muscle that opposes the action of the agonist. While the agonist contracts to produce movement, the antagonist relaxes to allow that movement to occur. This concept is important for understanding muscle balance and control during physical activities.