1. Origin Classification and Naming
The Muscular System
Origin
Classification
and Naming

2. Anatomy of the Muscular System
Origins, Insertions, and Actions
Origin
Muscle attachment that remains fixed
Insertion
Muscle attachment that moves
Action
What joint movement a muscle produces

3. Anatomy of the Muscular System
A single skeletal muscle, such as the triceps muscle, is attached at its origin to a large area of bone; in this case, the humerus.

4. Anatomy of Skeletal MuscleAnatomy of the Muscular System
At its other end, the insertion, it tapers into a glistening white tendon which, in this case, is attached to the ulna, one of the bones of the lower arm.

5. Anatomy of the Muscular System
Extensor – Any muscle that opens a joint increasing the angle between components of a limb, such as straightening the knee or elbow and bending the wrist or spine.
Flexor – A skeletal muscle whose contraction bends a joint, decreasing the angle between components of a limb, such as bending the knee or elbow. This action is known as flexion.
Antagonistic Pair- Muscles that are functional opposites, if one produces flexion, then the other's primary action is extension

6. Anatomy of the Muscular System
Primary Action Categories
Prime mover (agonist)- muscle with the major responsibility for a certain movement
Synergist - muscle that aids a prime mover in a movement and helps prevent rotation
Antagonist - Opposed muscle to an action
Fixator – stabilizes the origin of a prime mover

7. Naming of Skeletal Muscles
Direction of muscle fibers
Example: rectus (straight)
Relative size of the muscle
Example: maximus (largest)
Location of the muscle
Example: many muscles are named for bones (e.g., temporalis)
Number of origins
Example: triceps (three heads)….

8. Naming of Skeletal Muscles
Location of the muscles origin and insertion
Example: sterno (on the sternum)
Shape of the muscle
Example: deltoid (triangular)
Action of the muscle
Example: flexor and extensor (flexes or extends a bone)