1. Muscle System

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

3. Classification of Skeletal Muscles

4. Types of Muscles Muscles can be classified by action
Agonist (prime mover)
Primary responsible for the movement
Antagonist
Opposes the agonists
Synergist
Aids the action of agonists
Fixator

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

6. Names of skeletal muscles
Names give clues to muscle characteristics
Location of muscle’s origin and insertion
Sternohyoid
Direction of fibers
Tranverse, oblique, rectus
Number of origins
Biceps, triceps

7. Names of skeletal muscles
Size of the muscle
Maximus, minimus
Shape
Deltoid, trapezius
Action
Adductor, flexor
Location of the muscle
Frontalis, orbicularis

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

9. Organization of skeletal muscle fibers

10. Muscles of the Head and Neck

11. Head

12. Muscles of the head and neck
Epicranius muscles
Occipital
O: occipital bone
I: galea aponeurotic
A: pulls the scalp posteriorly
Frontal
O: galea aponeurotic
I: skin of the eyebrow
A: raise the eyebrow
Geilia apouniurotic

13. Muscles of the head and neck
Orbicularis oculi
O: frontal and maxillary bones
I: eyelid
A: closes eyes
Corrugator supercilli
O: frontal bone
I: skin of eyebrow
A: draws eyebrow inferiorly and medially

14. Muscles of the head and neck
Levator labii superioris
O: zigomatic and maxilla bones
I: upper lip
A: raises upper lips
Depressor labii inferioris
O: mandible
I: lower lip
A: pulls lower lip inferiorly

15. Muscles of the head and neck
Depressor anguli oris
O: mandible
I: angle of mouth
A: pulls corner of mouth down and laterally
Mentalis
I: skin of chin
A: protudes lower lip

16. Muscles of the head and neck
Zigomatics
O: zigomatic bone
I: corner the mouth
A: smiling muscle
Risorius
O: masseter
I: angle of the mouth
A: pulls corner of lips laterally

17. Muscles of the head and neck
Orbicularis oris
O: maxilla and mandible
I: lips
A: compresses lips
Buccinator
I: orbicularis oris
A: compresses the cheek (whistling)

18. Muscles of Mastication

19. Muscles of mastication
Masseter muscles
O: zigomatic and maxilla bones
I: mandible
A: closes the jaw
Temporalis muscles
O: temporal fossa

20. Muscles of mastication
Pterygoids
O: sphenoid, palatine and maxillary bones
I: mandible
A: elevates mandible, grinding the teeth
Buccinator

21. Muscles of the head and neck
Platysma
O: fascia of chest and deltoid
I: mandible, skin, corner of the mouth
A: depresses mandible, pulls lip back and down
Sternocleidomastoid
O: manubrium and clavicle
I: temporal and occipital bones
A: flexion forward of the neck

22. Neck

23. Neck

24. Muscles of the head and neck
Scalenes – anterior, middle, posterior
O: cervical vertebrae
I: first 2 ribs
A: elevates first 2 ribs
Digastric
O: mandible and mastoid process
I: hyoid
A: elevates hyoid bone

25. Muscles of the head and neck
Mylohyoid
O: mandible
I: hyoid bone
A: elevates hyoid bone
Sternohyoid
O: manubrium and clavicle
A: depresses hyoid bone

27. Extrinsic eye muscles Inferior and superior rectus muscles
Lateral and medial rectus muscles
Inferior oblique muscles
Elevates the eye and turns it laterally
Superior oblique muscles
Depresses the eye and turns it laterally

28. Chapter 25
Muscles of the Trunk

29. Muscles of the trunk and shoulder
Serratus anterior muscles
O:ribs
I: scapula (anterior surface)
A: fixates, protracts the scapula
Pectoralis minor muscles
O: ribs
I: scapula
A: ribs fixed: moves scapula forward and inferiorly and with scapula fixed it moves up the rib cage

30. Muscles of the trunk and shoulder
Deltoid muscles
O: clavicle and scapula
I: humerus
A: abduction of the shoulder
Pectoralis Major
O: clavicle, sternum, ribs
A: agonist for shoulder flexion

31. Muscles of the thorax (front)

32. Muscles of Respiration
External intercostal
O: rib above
I: rib below
A: elevates rib cage
Internal intercostal
O: rib below
I: rib above
A: depresses rib cage

33. Muscles of Respiration

34. Muscles of Respiration
Diaphragm
O: ribs and its cartilage, sternum, vertebrae
I: central tendon of the diaphragm
A: prime action in inspiration

35. Diaphragm

36. Muscles of the Trunk (back)

37. Muscles of the trunk (back) and shoulder
Supraspinatus muscles
O: scapula
I: humerus
A: synergist for arm abduction
Infraspinatus muscles
A: helps to hold the head of the humerus in the glenoid cavity, lateral rotation of humerus

38. Muscles of the trunk (back) and shoulder
Teres major
O: scapula
I: humerus
A: adducts humerus, medial rotation of humerus
Teres minor muscles
A: helps to hold the head of the humerus in glenoid cavity, lateral rotation of the humerus

39. Muscles of the trunk (back) and shoulder
Trapezius muscles
O: occipital bone, vertebrae
I: scapula, clavicle
A: extend head, elevate scapula
Rhomboids
O: vertebrae
I: scapula
A: adduct and stabilize scapula

40. Muscles of the trunk (back) and shoulder
Levator scapulae
O: vertebrae
I: scapula
A: elevates scapula
Latissimus dorsi muscles
O: vertebrae, ribs, ilium
I: humerus
A: agonist for shoulder extension

41. Muscles of Abdominal Wall

42. Muscles of Abdominal Wall
Rectus abdominis
O: pubis
I: xiphoid process, ribs
A: flexes vertebral column,increase abdominal pressure
External oblique,
O: ribs
I: linea alba, pubis, ilium
A: see above, helps trunk rotation and lateral flexion

43. Muscles of Abdominal Wall
Internal oblique
O: lumbar fascia, ilium, inguinal ligament
I: linea alba, pubis, ribs
A: same as external oblique
Transversus abdominis
O: ribs, inguinal ligament, ilium, lumbar fascia
I: linea alba, pubis
A: compresses abdominal content

44. Chapter 25
Muscles of the Arm

45. Muscles of the arm Biceps brachii muscle O: scapula, shoulder joint
I: radius
A: agonist for flexion of the elbow

46. Muscles of the arm

47. Muscles of the arm Brachialis O: humerus I: ulna A: flex the elbow
Brachioradialis
I: radius
A: synergist for flexion of the elbow

48. Muscles of the arm

49. Muscles of the arm Triceps brachii muscle O: scapula, humerus I: ulna
A: agonist for extension of the elbow

50. Muscles of the arm

51. Muscles of the arm

52. Rotator Cuff Muscles
Supraspinatus, infraspinatus, teres minor, and subscapularis
Function mainly to reinforce the capsule of the shoulder

53. Rotator Cuff Muscles

54. Muscles of the forearm Flexion of the wrist (O: humerus)
Flexor carpi ulnaris
I: metacarpus and carpus
Flexor carpi radialis
I: metacarpus
Palmaris longus
I: palm of the hand
A: also extends the palm of the hand

55. Muscles of the arm and forearm

56. Muscles that affect the wrist
Extension of the wrist (O: humerus)
Extensor carpi radialis
I: metacarpus
Extensor carpi ulnaris
Pronation of the forearm (I: radius)
Pronator teres muscle
O: humerus

57. Muscles of the forearm

58. Muscles of the forearm

59. Muscles of the forearm Extensors of the digitus Extensor digitorum
O: humerus
I: phalanges

60. Chapter 25
Muscles of the Leg

61. Muscles of the pelvis and lower limbs
Gluteus maximus
O: ilium, sacrum, coccyx
I: femur
A: extension of thigh (climbing stairs)
Gluteus medius and minimus
O:ilium
A: abducts thigh, steadies pelvis

62. Muscles of the leg Tensor fascia latae O: ilium I: fascia latae
A: flexes, abducts the thigh; tenses the fascia latae

63. Muscles of the leg

64. Iliopsoas muscle
Formed from the merging of the psoas major and the iliacus muscles
O: ilium, vertebrae
I: femur
Flexes trunk on thigh, flexes thigh

65. Muscles of the Leg

66. Muscles of the leg Sartorios O: ilium I: tibia
A: flexes the thigh and helps in crossing the leg
Adductors of the leg
O: pubis
I: femur

67. Muscles of the pelvis and lower limbs
Gracilis
O: pubis
I: tibia
A: adducts, flexes and medially rotates the thigh

68. Muscles of the leg Quadriceps (I: tibia; A: extends the knee)
Rectus femoris
O: ilium
Vastus medialis, intermedius, lateralis
O: femur

69. Leg

70. Leg

71. Muscles of the leg The hamstrings (O: ischium; I: tibia;
A: extend thigh, flexes knee)
Biceps femoris muscles
Semimembranosus muscles
Semitendinosis muscles

72. Muscles of the lower leg
Plantar flexion (I: calcaneal tendon)
Gastrocnemius muscle
O: femur
Soleus muscle
O: fibula and tibia
Eversion and plantar flexion
Fibularis muscle
O: fibula
I: metatarsal bones (lateral side)

73. Muscles of the lower leg

74. Muscles of the lower leg
Popliteus
O: femur
I: tibia
A: unlocks the knee joint

75. Muscles of the leg

76. Muscles of the lower leg
Tibialis anterior
O: tibia
I: metatarsus and cuneiforme
A: dorsiflexion of the foot
Tibialis posterior
I: tarsal and metatarsal bones
A: foot inversion

77. Muscles of the lower leg
Extensor digitorum
O: Tibia and fibula
I: Digitus
A: Extends the digits

78. Chapter 25
Cat Dissection

79. Skinning the Cat Leave the skin of the back attached.
Do not skin paws, tail, genital area, or head.
Remove fat if possible.
When you are done, use the skin to wrap the cat in.
Use the pencil and tape to label the bag.

80. Skinning the Cat
Cut the bag from the top to allow you to store the cat in it.
Keep as much embalming fluid as possible in the cat for it’s preservation.
Use several rubber bands; if one breaks, the bag will remain closed.
Clean and dry tray, tools and lab bench before leaving.

81. Cat Dissection – Neck Muscles
Mylohyoid
Digastric
Sternohyoid
Sternothyroid
Thyrohyoid

82. Cat Dissection – Thoracic Muscles
Anterior muscles
Pectoralis
Major and
Minor
Serratus anterior
Intercostals
Internal
External

83. Cat Dissection – Thoracic Muscles
Posterior muscles
Trapezius
Latissimus dorsi
Rhomboids
Supraspinatus
Infraspinatus

84. Cat Dissection – Abdominal Muscles
External oblique
Internal oblique
Rectus abdominis
Transversus abdominis

85. Cat Dissection – Arm Muscles
Brachial muscles
Biceps brachii
Triceps brachii
Long head
Lateral head

86. Cat Dissection – Arm Muscles
Antebrachial muscles
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Extensor carpi ulnaris
Extensor digitorum
Extensor carpi radialis

87. Cat Dissection – Leg Muscles
Upper leg
Sartorius
Gracilis
Rectus femoris
Vastus lateralis
Vastus medialis
Adductors

88. Cat Dissection – Leg Muscles
Semimembranosus
Semitendinosus
Biceps femoris
Lower leg
Gastrocnemius
Soleus
Tibialis anterior
Extensor digitorum
Fibularis