1. ANATOMY OF THE MUSCULAR SYSTEM

2. Anatomy of the Muscular System
Origin
Muscle attachment that remains fixed
Insertion
Muscle attachment that moves
Action
What joint movement a muscle produces
i.e. flexion, extension, abduction, etc.

3. Organization of Muscle Fibers
Four patterns of fascicle organization:
(1) Parallel muscle
(2) Convergent muscle
(3) Pennate muscle
(4) Circular muscle

4. Parallel Muscle
Muscle fibers arranged parallel to the long axis of the muscle
EX: most of the skeletal muscles, like biceps
When parallel muscle contracts, it gets shorter in length and larger in diameter

5. Convergent Muscle
The muscle fibers are spread over a broad area, but all the fascicles converge at one common attachment site
Muscle fibers spread out like a fan or broad triangle
EX: pectoralis muscles

6. Pennate Muscle
Fascicles form a common angle with the tendon, and contain more muscle fibers than parallel muscles, so more tension is produced during contraction
EX: unipennate – all fibers on the same side of the tendon: extensor digitorum
Bipennate – fibers on both sides of the tendon: rectus femoris

7. Circular Muscle
Fibers are concentrically arranged around an opening or a recess
When the muscle contracts, the diameter of the opening closes
EX: orbicularis oculis

8. For muscles to create a movement, they can only pull, not push
Muscles in the body rarely work alone, & are usually arranged in groups surrounding a joint
A muscle that contracts to create the desired action is known as an agonist or prime mover (EX: biceps contracts)
A muscle that helps the agonist is a synergist
A muscle that opposes the action of the agonist, therefore undoing the desired action is an antagonist (EX: triceps extends the elbow)

9. How Muscles are Named… 1. Orientation of muscle fibers 2. Location
3. Relative Position
4. Structure, Shape, and Size
5. Origin and Insertion
6. Action

10. How Muscles are Named… 1. Orientation of fibers Rectus = straight
Transversus = fibers run across the long axis of the body
Oblique = fibers run at an oblique angle to the long axis

11. How Muscles are Named… 2. Location
Muscles are named for their location or body region
EX: temporalis, frontalis, femoris

12. How Muscles are Named… 3. Relative Position
Muscles visible at the surface of the body are called externus or superficialis
Deeper muscles are called internus or profundis

13. How Muscles are Named… 4. Structure, Shape, and Size
Some muscles named for the number of tendons of origin (EX: biceps or triceps brachii)
Shape: deltoid, rhomboid
Long muscles called longus (long) or longissimus (longest)
Short muscles called brevis

14. How Muscles are Named… 5. Origin and Insertion
First name will indicate origin, second name the insertion
EX: genioglossus muscle
Origin = chin (genio)
Insertion = tongue (glossus

15. How Muscles are Named… 6. Action
Some muscles are named for the action they produce when contracted.
EX: extensor, flexor, retractor, abductor, adductor, levator, pronator, etc

16. How Muscles are Named: Action
Flexion = decreasing the angle between 2 bones (dorsiflexion = decrease angle between foot and the shin; plantar flexion = pointing toes
Extension = increasing the angle between 2 bones
Abduction = moving a body part away from the midline
Adduction = moving a body part toward the midline
Circumduction = movement in a circular motion

17. How Muscles are Named: Action
Rotation = turning movement of a bone around its long axis
Supination = thumbs up
Pronation = thumbs down
Inversion = turning sole of foot in
Eversion = turning sole of foot out
Elevation = lifting a body part
Depression = returning body part to its pre-elevated position

18. An Overview of the Major Skeletal Muscles
Figure 7-11(a)

19. An Overview of the Major Skeletal Muscles
Figure 7-11(b)

20. Anatomy of the Muscular System
Muscles of the Head and Neck
Anatomy of the Muscular System
Figure 7-12(a)

21. Anatomy of the Muscular System
Muscles of the Head and Neck
Anatomy of the Muscular System
Figure 7-12(c)

22. Anatomy of the Muscular System
Muscles of the Spine
Figure 7-14

23. Anatomy of the Muscular System
Oblique and Rectus Muscles and the Diaphragm
Figure 7-15(a)

24. Anatomy of the Muscular System
Muscles of the Shoulder
Anatomy of the Muscular System
Figure 7-17(a)

25. Anatomy of the Muscular System
Muscles of the Shoulder
Anatomy of the Muscular System
Figure 7-17(b)

26. Anatomy of the Muscular System
Muscles that Move the Arm
Anatomy of the Muscular System
Figure 7-18(a)

27. Anatomy of the Muscular System
Muscles that Move the Arm
Anatomy of the Muscular System
Figure 7-18(b)

28. Anatomy of the Muscular System
Muscles That Move the Forearm and Wrist
Anatomy of the Muscular System
Figure 7-19

29. Anatomy of the Muscular System
Muscles That Move the Thigh
Anatomy of the Muscular System
Figure 7-20(a)

30. Anatomy of the Muscular System
Muscles That Move the Thigh
Anatomy of the Muscular System
Figure 7-20(b)

31. Anatomy of the Muscular System
Muscles That Move the Leg
Anatomy of the Muscular System
Figure 7-21

32. Anatomy of the Muscular System
Muscles That Move the Foot and Toes
Anatomy of the Muscular System
Figure 7-22(a)

33. Anatomy of the Muscular System
Muscles That Move the Foot and Toes
Figure 7-22(b)

34. Anatomy of the Muscular System
Muscles That Move the Foot and Toes
Figure 7-22(c)

35. Anatomy of the Muscular System
Muscles That Move the Foot and Toes
Figure 7-22(d)