1. The Muscular System

2. Functions of Skeletal Muscle
Movement – muscle move bones by pulling not pushing.
Synergists – any movement is generally accomplished by more than one muscle. All of the muscles responsible for a particular movement are synergists. The one that is most responsible for the movement is the Prime Mover.
Antagonists - muscles and muscle groups usually work in pairs – example the biceps flex your arm and its partner, the triceps, extend your arm. The two muscles are antagonists, i.e. cause opposite actions. When one contracts the other relaxes.
Levators – muscle that raise a body part.

3. Functions of Skeletal Muscle
Maintenance of posture or muscle tone
We are able to maintain our body position because of tonic contractions in our skeletal muscles. These contractions don’t produce movement yet hold our muscles in position.
Heat production – contraction of muscles produces most of the heat required to maintain body temperature.

4. Muscular System Muscles are responsible for all types of body movement
3 basic muscle types are found in the body
Skeletal muscle
Cardiac muscle
Smooth muscle

5. Skeletal Muscle Characteristics
Most attach to bones by tendon
Cells are multinucleate
Striated—have visible binding
Voluntary
Cells surrounded & bundled by connective tissue

6. Smooth Muscle Characteristics
Has no striations
Spindle-shaped cells
Single Nucleus
Involuntary—no conscious control
Found mainly in the walls of hollow organs

7. Characteristics of Cardiac Muscle
Has striations
Usually has a single nucleus
Joined to another cardiac muscle cell
Involuntary
Found only in the heart

8. Organization of Skeletal Muscles

9. Naming Skeletal Muscles
Direction of
Fibers
Location
Size
Number
Origins Of
Shape
Insertion
Origin
&
Action

10. Direction of Muscle Fibers
Relative to the Midline
RECTUS = parallel to the midline
Rectus Abdominus
TRANSVERSE = perpendicular to midline
Transverse Abdominus
OBLIQUE = diagonal to midline
External Oblique

11. Location Structure near which muscle is found
FRONTALIS = near FRONTAL bone
OCCIPITALIS = near OCCIPITAL bone

12. Size Relative Size of Muscle MAXIMUS = largest MEDIUS = middle
Gluteus Maximus
MEDIUS = middle
Gluteus Medius
MINIMUS = smallest
Gluteus Minimus
LONGUS = longest
Fibularis Longus
BREVIS = short
Fibularis Brevis
TERTIUS = shortest
Fibularis Tertius

13. Number of Origins Number of tendons of origin BICEPS = Two
Biceps Brachii
Biceps Femoris
TRICEPS = Three
Triceps Brachii
QUADRICEPS = Four
Quadriceps Femoris

14. Shape Relative Shape of the Muscle DELTOID = triangular shape Δ
TRAPEZIUS = trapezoid shape  SERRATUS = saw- toothed ♒
RHOMBOIDEUS = rhomboid shape 
TERES = round ○

15. Origin & Insertion Origin – attachment to an immoveable bone
Insertion – attachment to a movable bone
ILIO COSTALIS= attaches to the ilium & ribs (costal = ribs)