Download Muscle Classification - Decker

Chapter 11
 The
muscular system includes all the
skeletal muscles that can be controlled
voluntarily.
 There are about 700 identified skeletal
muscles in the human body.
A.
Muscle Attachment
1. Origin- where a muscle begins
a. Generally remains stationary
b. Generally proximal
2. Insertion- where a muscle ends
a. Generally moveable
b. Generally distal
3. Contraction results in the shortening of the
distance between the origin & insertion,
which causes movement at the insertion
end.
 Flexion
 Extension
 Rotation
 Circumduction
 Adduction
 Abduction
 Pronation
 Supination
 Protraction
 Retraction
 Inversion
 Eversion
 Lateral
 Opposition
Flexion
 Depression
 Elevation
Prime Mover / Agonist- muscle whose
contraction is chiefly responsible for
producing a particular movement.
A.
•
Ex. biceps brachii
Antagonists- muscle that opposes
agonist.
B.
•
Ex. triceps brachii
C.
Synergist- assists the prime mover
D.
Fixator- stabilizes agonist to prevent
movement.
A.
Fascicle Organization:
1. Rectus- “straight”- parallel muscles whose
fibers run along the long axis of the body
2. Transversus- muscles whose fibers run
across the long axis of the body
3. Obliquus- muscles whose fibers run at an
angle to the long axis of the body
B.
Relative Position:
1. Externus- visible at body surface
2. Superficialis- visible at body surface
3. Internus- found beneath the surface
4. Profundus- found beneath the surface
5. Extrinsic- superficial muscles that stabilize an
organ
6. Intrinsic- muscles located entirely within the
organ
C.
Structure:
1. Ex. biceps brachii (2 tendons of origin)
2. Ex. quadriceps group (4 tendons of origin)
D.
Size:
1. Longus / Brevis - long / short muscles
2. Major / Minor - large / small muscles
E.
Shape:
1. Ex. Trapezius- trapezoid-shaped
2. Ex. Rhomboideus- rhomboid-shaped
F.
Origin & Insertion:
1. Ex. genioglossus
a. Origin: chin “geneion”
b. Insertion: tongue “glossus”
G.
Action:
1. Flexor
2. Extensor
3. …