Anatomy- Muscles

Question 1

What are the functions of the muscular system?

Answer 1

The main function of the muscular system is movement.
Related to the function of movement is the muscular system’s second function: the maintenance of posture and body position.

Question 2

Muscles have four major functions. What are they?

Answer 2

• Energize (heat) the body
• Protect internal organs
• Generate movement
• Maintain posture

Question 3

What are muscles?

Answer 3

Basically, muscles are groups of cells in bundles that have the ability to generate tension, lengthen, contract and relax.

Question 4

Muscles have beginning and end points. What are they called?

Answer 4

Origin (primarily at the point which is stabilizing bone where the muscle attaches).

Insertion (primarily at the point on the bone which is moved by the action of the muscle).

Question 5

What is antagonistic muscle action?

Answer 5

Muscles usually work in pairs or groups, like when the quadriceps lengthens, the hamstring engages, or when the biceps flex the elbow and the triceps extend it.

The working (or contracting) muscle is called the prime mover or agonist. The relaxing (or lengthening) muscle is the antagonist.

The prime mover is helped by other muscles called synergists, or fixators. These contract at the same time as the prime mover. They hold the body in position so that the prime mover can work smoothly.

Question 6

When muscles cause a limb to move through the joint’s range of motion, they act in the following cooperating groups:

Answer 6

Agonists - These muscles cause the movement to occur. They create the normal range of movement in a joint by contracting. Agonists are also referred to as prime movers.

Antagonists - These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position.

Synergists - These muscles perform, or assist in performing, the same set of joint motion as the agonists. Synergists are sometimes referred to as neutralizers or fixators because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.