Muscular system

1. Muscular system • Includes all skeletal muscle tissue that can be controlled voluntarily

2. Organization of skeletal muscle fibers • Parallel muscle • Convergent muscle • Pennate muscle • Unipennate • Bipennate • Multipennate • Circular muscle (sphincter)

3. Figure 11.1 Different Arrangements of Skeletal Muscle Fibers Figure 11.1

4. Levers • Rigid structure that moves on a fixed point, the fulcrum • Changes direction and strength of applied force • Changes distance and speed of movement • Three classes • First class • Second class • Third class • Most common in the body PLAY Animation: First, Second and Third-Class Levers

5. Figure 11.2 The Three Classes of Levers Figure 11.2a

6. Figure 11.2 The Three Classes of Levers Figure 11.2b

7. Figure 11.2 The Three Classes of Levers Figure 11.2c

8. Origins and Insertions • Muscles can be identified by origin, insertion and action • Origin = stationary end • Insertion = movable end

9. Actions • Muscles can be classified by action • Agonist (prime mover) • Antagonist • Synergist • Fixator

10. Names of skeletal muscles • Names give clues to muscle characteristics • Location • Fascicle organization • Relative position • Structure • Size • Shape • Origin and insertion • Action

11. Axial and Appendicular Muscles • Axial musculature arises on axial skeleton • Positions head and spinal column and moves the rib cage • Appendicular musculature moves and stabilizes components of the appendicular skeleton

12. Figure 11.3 An Overview of the Major Skeletal Muscles Figure 11.3

13. Figure 11.3 An Overview of the Major Skeletal Muscles Figure 11.3

14. Axial muscles • Logical groupings based on location and/or function • Head and neck • Vertebral column • Oblique and rectus muscles • Pelvic floor

15. Muscles of the head and neck • Facial expression muscles • Orbicularis oris • Occipitofrontalis muscles

16. Figure 11.4 Muscles of Facial Expression Figure 11.4a

17. Figure 11.4 Muscles of Facial Expression Figure 11.4b

18. Extrinsic eye muscles (oculomotor or extra-ocular muscles) • Inferior and superior rectus muscles • Lateral and medial rectus muscles • Inferior and superior oblique muscles

19. Figure 11.5 Extrinsic Eye Muscles Figure 11.5

20. Figure 11.6 Muscles of Mastication Figure 11.6

21. Oblique and rectus muscles • Oblique • Scalene muscles • Intercostal muscles • Transverses muscles • External and internal intercostals • Diaphragm

22. Figure 11.11 Oblique and Rectus Muscles and the Diaphragm Figure 11.11

23. Muscles of the shoulders and upper arms • Trapezius muscles • Affect the position of the shoulder girdle, head and neck • Muscles inserting on the scapula • Rhomboid muscles • Levator scapulae muscles • Serratus anterior muscles • Subclavius muscles • Pectoralis minor muscles

24. Figure 11.13 An Overview of the Appendicular Muscles of the Trunk Figure 11.13a

25. Figure 11.13 An Overview of the Appendicular Muscles of the Trunk Figure 11.13b

26. Figure 11.14 Muscles that Position the Pectoral Girdle Figure 11.14a

27. Figure 11.14 Muscles that Position the Pectoral Girdle Figure 11.14b

28. Shoulder muscles • Adductors • Deltoid muscles • Supraspinatus muscles • Medial rotators • Subscapularis muscles • Teres major muscles • Lateral rotation • Infraspinatus muscles • Teres minor muscles

29. Figure 11.15 Muscles that Move the Arm Figure 11.15a

30. Figure 11.15 Muscles that Move the Arm Figure 11.15b

31. More shoulder movements • Flexion and adduction • Coracobrachialis • Flexion of the shoulder joint • Pectoralis major muscles • Extension of the shoulder joint • Latissimus dorsi muscles

32. Muscles of the shoulders and upper arms • Trapezius muscles • Affect the position of the shoulder girdle, head and neck • Muscles inserting on the scapula • Rhomboid muscles • Levator scapulae muscles • Serratus anterior muscles • Subclavius muscles • Pectoralis minor muscles

33. Figure 11.13 An Overview of the Appendicular Muscles of the Trunk Figure 11.13a

34. Figure 11.13 An Overview of the Appendicular Muscles of the Trunk Figure 11.13b

35. Figure 11.14 Muscles that Position the Pectoral Girdle Figure 11.14a

36. Figure 11.14 Muscles that Position the Pectoral Girdle Figure 11.14b

37. Shoulder muscles • Adductors • Deltoid muscles • Supraspinatus muscles • Medial rotators • Subscapularis muscles • Teres major muscles • Lateral rotation • Infraspinatus muscles • Teres minor muscles

38. Figure 11.15 Muscles that Move the Arm Figure 11.15a

39. Figure 11.15 Muscles that Move the Arm Figure 11.15b

40. More shoulder movements • Flexion and adduction • Coracobrachialis • Flexion of the shoulder joint • Pectoralis major muscles • Extension of the shoulder joint • Latissimus dorsi muscles

41. Flexors of the knee • The hamstrings • Biceps femoris muscles • Semimembranosus muscles • Semitendinosis muscles • Popliteus muscle unlocks the knee joint

42. Extensors of the knee • Quadriceps femoris • Three vastus muscles • Rectus femoris muscle PLAY Animation: Muscles of the lower limbs

43. Movements at the ankle • Plantar flexion • Gastrocnemius muscle • Soleus muscle • Eversion and plantar flexion • Fibularis muscle • Foot position and toe movement is accomplished by muscles originating on the talus and metatarsal bones

44. Figure 11.21 Extrinsic Muscles That Move the Foot and Toes Figure 11.21a, b

45. Figure 11.21 Extrinsic Muscles That Move the Foot and Toes Figure 11.21c, d

46. Figure 11.22 Intrinsic Muscles of the Foot Figure 11.22a

47. Figure 11.22 Intrinsic Muscles of the Foot Figure 11.22b

48. Figure 11.22 Intrinsic Muscles of the Foot Figure 11.22c