1. Ch. 10: The Muscular System:
Three things that a muscle will be assigned to perform:
1.) Agonist: Prime mover, main muscle or muscles doing the intended job or performance.
2.) Antagonists: Muscle or a group of muscles that is associated with agonist in whatever movement the agonist does the antagonist does the opposite of.
- If the agonist is flexing the antagonist is extending.
3.) Synergist: Muscle or muscles that aid in the movement of either the agonist or the antagonist muscles.

2. The Muscular System:
Just like the skeletal system, the muscular system is divided into two groups:
Axial muscle group: Head, thoracic, spine.
Appendicular muscle group: Arms, hands, legs, feet.

3. The purpose of the muscular system is to do work.
In order to complete this task the muscles attaching to the bones allows them to act as levers.
Three different types of levers.
1st class lever
2nd class lever
3rd class lever

4. The Muscular System: Levers
1st class lever: fulcrum or pivot point is in the middle, resistance on one side and the effort is on the other side.
- tilting your chin back, spine is the pivot, resistance is your chin, effort is the muscles attached to the base of the head.
Load
Fulcrum
Effort
Effort
Load
Fulcrum
Effort
Load
Fulcrum

5. The Muscular System: Levers
2nd class lever: fulcrum is at one end, the load is in the middle, effort is at the other end.
- Lifting your heel off the ground, pivot is your toes, resistance is the heel, effort is your calf muscles.
Fulcrum
Load
Effort
Fulcrum
Effort
Load

6. The Muscular System: Levers
3rd class lever: fulcrum is at one end, effort is in the middle, resistance is at the other end.
- Doing a bicep curl, pivot is your elbow, resistance is in your hand, effort is coming from your forearm (distal).
Fulcrum
Effort
Load

7. The Muscular System:
Frontalis:
O: Galea aponeurotica (sheath on the mid head)
I: Above the eyebrow
F: Raise eyebrows

8. The Muscular System:
Occipitalis:
O: External protuberance of the occipital bone
I: Galea aponeurotica
F: Retract scalp

9. The Muscular System:
Temporalis:
O: Temporal lines of the skull (suture sites)
I: Coronoid process
F: Elevate mandible

10. The Muscular System:
Orbicularis oculi:
O: Medial portion of the eye orbit
I: Skin around the eyelid
F: Close and open eye

11. The Muscular System:
Zygomaticus:
O: Zygomatic bone
I: Skin on the corner of the mouth
F: Draw the corners of the mouth up and back

12. The Muscular System:
Masseter:
O: Zygomatic arch
I: Lateral surface of the mandible
F: Elevate mandible

13. The Muscular System:
Buccinator:
O: Distal portions of the maxilla and mandible
I: Orbicularis oris
F: Compress checks

14. The Muscular System:
Orbicularis oris:
O: Maxilla and mandible
I: Lips
F: Compress lips

15. The Muscular System:
Sternocleidomastoid:
O: Superior aspect of sternum and clavicle
I: Mastoid process
F: flex the neck, allows the head to pivot

16. The Muscular System:
External intercostals (outside of the ribcage):
O: Inferior border of each rib above
I: Superior border of each rib below
F: Elevate ribs, protect internal organs

17. The Muscular System:
Internal intercostals (inside the ribcage):
O: Superior border of the rib below
I: Inferior border of the rib above
F: Depress rib

18. The Muscular System:
External oblique (outside ab muscles):
O: Lower portion of the eighth rib
I: Iliac crest
F: Compress abdomen

19. The Muscular System:
Internal oblique (inside body cavity ab muscle):
O: Iliac crest
I: Lower portion of the ribs, xiphoid process
F: Compress the abdomen

20. The Muscular System:
Transverse abdominous (inner most ab muscle):
O: Cartilage of lower ribs, iliac crest
I: Pubis
F: Compress abdomen

21. The Muscular System:
Rectus abdominous (front portion of abs):
O: Superior aspect of the pubis symphysis
I: Inferior surface of ribs 5-7, xiphoid process
F: Depress ribs

22. The Muscular System:
Serratus anterior:
O: Lateral side of ribs one through nine
I: Anterior surface of scapula, medial border
F: protract scapula against the chest wall, boxers muscle

23. The Muscular System:
Pectoralis Major:
Fan shaped muscle that is superficial on the anterior side of the thoracic cavity
O: Sternum (body), clavicle
I: Greater tubercle of the humerus
F: Adduct of the arm, helps with throwing and flexion of the arm

24. The Muscular System:
Pectoralis Minor:
Lies deep to the pectoralis major.
O: Ribs 3-5
I: Coracoid process of the scapula
F: Raise ribs 3-5, depress glenoid cavity

25. The Muscular System:
Deltoid:
Thick three bodied muscles
O: Clavicle, acromion spine of the scapula (posterior side)
I: Proximal head of the humerus
F: Abduction, forward flexion, and backward flexion

26. The Muscular System:
Latissimus dorsi (Lats):
Triangular muscle in the lower back
O: Spinous process of the lower thoracic and lumbar back
I: Between greater and lesser tubercle of humerus
F: Arm extension and adduction

27. The Muscular System:
Trapezius
Upper back muscles
O: External protuberance of the occipital bone, C7 and all spinous process of thoracic vertebrae.
I: Acromion spine of scapula, lateral clavicle
F: Raise scapula, stabilize head

28. The Muscular System:
Levator scapulae:
Deep to the trapezius
O: Transverse process of C1 – C4
I: Upper portion of the medial border, above the scapula spine
F: Elevate and adduct scapula

30. The Muscular System:
Rhomboids:
Two muscles (minor and major) both lie deep to the trapezius
O: Spinous process of C7 – T5
I: Medial Border of scapula
F: Retract scapula, helps with posture

31. The Muscular System:
Rotator cuff:
Subscapularis:
Anterior muscle under the scapula
O: Ventral (front) surface of scapula, subscapularis fossa
I: Lesser tubercle of humerus
F: Assists in arm movement

33. The Muscular System:
Rotator cuff:
Supraspinatus:
Sits above the spine of the scapula
O: Medial border, superior aspect of the scapula, supraspinous fossa
I: Greater tubercle of humerus
F: Stabilize the shoulder

35. The Muscular System:
Rotator cuff:
Infraspinatus:
Sits below the spine of the scapula
O: Medial border, inferior aspect of the scapula, infraspinous fossa
I: Greater tubercle of the humerus
F: Stabilize humerus and aid in ROM

37. The Muscular System:
Rotator cuff:
Teres minor:
Small round muscle
O: Lateral, dorsal border of scapula
I: Greater tubercle of humerus
F: Stabilize humerus and aid in ROM

39. The Muscular System:
Rotator cuff:
Teres major:
Thick rounded, inferior to teres minor
O: posterior surface of scapula
I: groove of humerus
F: adducts humerus, external rotation of arm

40. The Muscular System:
Biceps brachii:
Anterior surface of upper arm
Composed of two heads (Biceps)
O: Coracoid process
I: Radial tuberosity
F: Flexion of the arm (flexion of the radius)

41. The Muscular System:
Brachialis:
Lies underneath the biceps brachii
O: Distal half of the humerus
I: Coronoid process of the ulna (anterior elbow)
F: Flexion of the arm (flexion of the ulna)

42. The Muscular System:
Brachioradialis:
Superficial muscle on the lateral side of the arm
O: Distal end of the humerus
I: Styloid process of radius
F: Synergist muscle for flexion of the arm

43. The Muscular System:
Triceps brachii:
Posterior surface of the upper arm
Composed of three heads (Triceps)
O: Superior, lateral border of the scapula
I: Olecranon process
F: Extension of the arm

44. The Muscular System:
Flexor digitorium superficialis:
Anterior surface of the lower arm
Four different muscles (one for each digit)
O: Medial epicondyle of the humerus
I: Middle phalanges of digits 2-5
F: Flex digits (curl)

45. The Muscular System:
Flexor pollicis longus:
Anterior surface of the lower arm
One muscle
O: Anterior surface of the distal radius
I: Distal phalanges of the thumb, anterior side
F: Flex the thumb

46. The Muscular System:
Flexor pollicis brevis:
Anterior surface of the lower arm
Synergist for the flexor pollicis longus
One muscle
O: Trapezium
I: Proximal phalange of the thumb
F: Flex the thumb

47. The Muscular System:
Extensor digitorium superficialis
Posterior surface of the lower arm
Four muscles, one for each digit
O: Lateral epicondyle of humerus
I: Distal phalanges of digits 2-5
F: Extend each digit

48. The Muscular System:
Supinator:
Anterior surface of the forearm. Lies deep to the flexor digit.
O: Lateral epicondyle of the humerus
I: upper 1/3 of the radius
F: Supination of the forearm into the ACP

49. The Muscular System:
Pronator teres:
Located on the anterior surface of the forearm. Lies deep to the flexor digit.
O: Medial epicondyle of the humerus
I: Lateral side of the shaft of the radius
F: Pronate the forearm out of the ACP

50. The Muscular System:
Flexor carpi radialis:
Located on the anterior surface of the forearm. Superficial to the flex. digit.
O: Medial epicondyle of the humerus
I: 2nd and 3rd metacarpals
F: flex wrist

51. The Muscular System:
Flexor carpi ulnaris:
Located on the anterior surface of the forearm. Superficial to the flex. digit.
O: medial epicondyle of the humerus, medial side of the olecranon process
I: pisiform, hamate, 5th metacarpal
F: flex the wrist

52. The Muscular System:
Extensor carpi radialis longus:
Located on the posterior surface of the forearm.
O: Lateral surface of the humerus superior to the condyle
I: 2nd metacarpal
F: Extend the wrist

53. The Muscular System:
Extensor carpi ulnaris:
Located posterior surface of the forearm
O: Lateral epicondyle of the humerus, shaft of the ulna
I: 5th metacarpal
F: Extends the wrist

54. The Muscular System:
Extensor pollicus longus:
Posterior surface of lower arm
One muscle
O: Posterior distal surface of radius and ulna
I: Distal phalange of thumb, posterior side
F: Extend thumb

55. The Muscular System:
Thigh and Pelvis
Ilopsoas:
Aids in ROM (flexion).
O: Iliac crest, lateral surface of the sacrum
I: Lesser trochanter on the femur
F: Flex of the hip when trunk is in a solid position.

56. The Muscular System:
Thigh and Pelvis
Adductor longus:
Main adductor muscle
Covers the middle portion of the adductor magnus
O: Pubis synthesis
I: Medial shaft of the femur
F: Flex the leg, laterally rotates leg, adduction

57. The Muscular System:
Thigh and Pelvis
Adductor magnus:
Synergist to the adductor longus
Large triangular with a broad insertion point
Lies deep to the adductor longus
O: Ischial tuberosity
I: Medial side of the femur (proximal head, shaft, distal head)
F: Aid in adduction of leg

58. The Muscular System:
Thigh and Pelvis
Adductor brevis:
Synergist for the add. Longus
Lies deep to the add. Longus
Superficial to the add. Magnus
O: Ischium
I: Above the add. Longus on the shaft of the femur
F: Aid in adduction

59. The Muscular System:
Thigh and Pelvis
Gracilis:
Medial portion of the thigh
Groin muscle
O: Body of the pubis bone
I: Medial surface of the proximal head of the tibia
F: Adduct thigh, flex hip, main walking muscle

60. The Muscular System:
Thigh and Pelvis
Sartorius:
Longest muscle in the body
O: Anterior portion of the iliac crest
I: Medial aspect of the proximal head of the tibia
F: Flex knee, laterally rotate knee

61. The Muscular System:
Thigh and Pelvis
Tensor fasciae latae:
Wide band of muscle located on the medial side of the thigh
O: Anterior aspect of the iliac crest
I: Lateral aspect of the proximal head of the tibia
F: Flex and medially rotate the knee

62. Located on the anterior side of the leg. Made up of four muscles
The Muscular System:
Thigh and Pelvis
Quadriceps
Located on the anterior side of the leg.
Made up of four muscles
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Extends knee

63. The Muscular System:
Thigh and Pelvis
Rectus femoris:
Superficial muscle in the thigh
Largest quad muscle
O: Anterior and inferior iliac crest
I: Superior border of the patella
F: Extend knee, flex the thigh, stabilize patella

64. The Muscular System:
Thigh and Pelvis
Vastus lateralis:
Lateral side of the thigh
Synergist to the rectus femoris
O: Greater trochanter of the femur
I: Lateral border of the patella
F: Extend knee, stabilize patella

65. The Muscular System:
Thigh and Pelvis
Vastus medialis:
Medial side of the thigh
Synergist for the rectus femoris
O: Proximal head of the femur
I: Medial surface of the patella
F: Extend knee, stabilize patella

66. The Muscular System:
Thigh and Pelvis
Vastus intermedius:
Lies deep to the rectus femoris
O: Proximal head of the femur
I: Superior border of he patella (underneath the rectus femoris insertion)
F: Extend knee, stabilize patella

67. The Muscular System:
Thigh and Pelvis
Tibialis anterior:
Anterior portion of the leg
Next to the tibia crest
O: Lateral condyle of the tibia
I: 1st cuneiform (medial) and the first metatarsal
F: Dorsiflexion

68. The Muscular System:
Thigh and Pelvis
Extensor digitorium longus:
Lateral side of the lower leg
O: Lateral condyle of the tibia and the majority (3/4) of the proximal fibula
I: Middle and distal phalanges of the digits 2-5
F: Extend toes

69. The Muscular System:
Thigh and Pelvis
Extensor hallucis longus:
Medial side of the lower leg
Great toe (big toe)
O: Medial fibula shaft
I: Distal phalange of the great toe
F: Extend great toe

70. Located on the posterior side of the thigh Flexes the knee
The Muscular System:
Thigh and Pelvis
Hamstrings:
Located on the posterior side of the thigh
Flexes the knee
Made up of three muscles:
Semimembranous
Biceps femoris
Semitendinous

71. The Muscular System:
Thigh and Pelvis
Semimembranous:
Lies on the medial portion of the thigh
Lies deep to the semitendinous
Larger than the semitendinous
O: Ischium
I: Medial condyle of the tibia
F: Flex knee

72. The Muscular System:
Thigh and Pelvis
Semitendinous:
Lies on the medial portion of the thigh
Superficial to the semimembranous
O: Ischium
I: Medial, superior tibial shaft
F: Flex knee

73. The Muscular System:
Thigh and Pelvis
Biceps femoris:
Lies on the lateral portion of the thigh
O: Ischium and the proximal head of the femur
I: Head of the fibula and lateral condyle of the tibia
F: Flex knee

74. Cushioning and protection for the pelvic girdle.
The Muscular System:
Thigh and Pelvis
Buttock muscles:
Cushioning and protection for the pelvic girdle.
Three muscles that make up the buttock muscles.
Gluteus maximus
Gluteus medius
Gluteus minimus

75. The Muscular System:
Thigh and Pelvis
Gluteus maximus:
Main bulk of the buttocks, superficial
O: Ilium, sacrum, coccyx
I: Proximal head of the femur
F: Extend leg when walking and climbing

76. The Muscular System:
Thigh and Pelvis
Gluteus medius:
Lies deep to the gluteus maximus
O: Ilium
I: Greater trochanter of femur via a small tendon
F: Stabilize pelvis when walking

77. The Muscular System:
Thigh and Pelvis
Gluteus minimus:
Lies deep to the gluteus medius
Main synergist buttock muscle
O: Ilium
I: Anterior border of the greater trochanter of the femur
F: Help stabilize the pelvis

78. The Muscular System:
Thigh and Pelvis
Gastronemius:
Superficial muscle
O: Medial and lateral condyle of the femur
I: Calcaneus
F: Plantar flexion

79. The Muscular System:
Thigh and Pelvis
Soleus:
Lies deep to the gastronemius
Synergist for the gastronemius
O: Proximal head of the tibia and fibula
I: Calcaneus (underneath the insertion of the gastronemius)
F: Plantar flexion

80. The Muscular System:
Thigh and Pelvis
Flexor digitorium longus:
Medial portion of the lower leg
O: Medial condyle of the tibia (posterior)
I: Distal phalanges of digits 2-5
F: Flex toes

81. The Muscular System:
Thigh and Pelvis
Flexor hallucis longus:
Great toe (big toe)
Medial portion of the lower leg
O: Middle of the fibula shaft
I: Distal phalange of the great toe
F: Flex the great toe