Skeletal Muscles: Functional Groups1.Prime movers–Provide the major force for producing a specific movement3.Antagonists–Oppose or reverse a particular movement
Skeletal Muscles: Functional Groups3.Synergists–Add force to a movement–Reduce undesirable or unnecessary movement5.Fixators–Synergists that immobilize a bone or muscle’s origin
Naming Skeletal Muscles•Location—bone or body region associated with the muscle•Shape—e.g., deltoid muscle (deltoid= triangle) •Relative size—e.g., maximus (largest), minimus (smallest), longus (long)•Direction of fibers or fascicles—e.g., rectus (fibers run straight), transversus, and oblique (fibers run at angles to an imaginary defined axis)
Naming Skeletal Muscles•Number of origins—e.g., biceps (2 origins) and triceps (3 origins)•Location of attachments—named according to point of origin or insertion •Action—e.g., flexor or extensor, muscles that flex or extend, respectively
Muscle Mechanics: Arrangement of Fascicles•Circular–Fascicles arranged in concentric rings (e.g., orbicularis oris)•Convergent–Fascicles converge toward a single tendon insertion (e.g., pectoralis major)
Muscle Mechanics: Arrangement of Fascicles•Parallel–Fascicles parallel to the long axis of a straplike muscle (e.g., sartorius)•Fusiform–Spindle-shaped muscles with parallel fibers (e.g., biceps brachii)•Pennate–Short fascicles attach obliquely to a central tendon running the length of the muscle (e.g., rectus femoris)
Figure 10.1(a)(b)(e)(d)(g)(f)(c)Circular(orbicularis oris)(b) Convergent(pectoralis major)(c) Parallel(sartorius)
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- Spring '09
- Extensor Digitorum Longus, Muscles of the upper limb, Extensor Carpi, Extensor Digitorum, Extensor digitorum brevis