1. Muscles Martini Chapter 11
Lab Activity 11: Group I
Muscles
Martini Chapter 11
Portland Community College
BI 231

2. Origin and Insertion
Origin: The place where the fixed end attaches to a bone, cartilage, or connective tissue.
Insertion: The site where the movable end attaches to another structure.

3. Muscles of facial Expression

4. frontalis Frontal belly
Epicranial Aponeurosis
Frontal belly
Action: Elevates eyebrows and wrinkles skin of forehead
Origin: Epicranial aponeurosis
Insertion: skin of eyebrow and bridge of nose

5. Occipitalis Occipital belly
Action: Pulls scalp posteriorly; wrinkles skin on posterior surface of neck
Origin: Superior nuchal line on occipital bone
Insertion: Epicranial aponeurosis (Galea aponeurotica)

6. Nasalis Action: Compresses nostrils, dilates nostrils
Origin: Maxillary bone and cartilage of nose
Insertion: Bridge of nose

7. Orbicularis Oculi
Action: Closes eyelids; acts during squinting and blinking
Origin: Medial aspect of bony orbit
Insertion: skin around eyelids

8. Orbicularis Oris
Action: Closes and purses lips as in speaking, kissing and whistling
Origin: Maxillary bone; mandible
Insertion: lips

9. Zygomaticus Major Action: Elevates corner of mouth
Origin: Zygomatic bone
Insertion: Angle of mouth

10. Zygomaticus minor Action: Raises upper lip. Origin: Zygomatic bone
Insertion: Upper lip

11. Mentalis Action: Protrudes lower lip; wrinkles skin on chin
Origin: Anterior surface of mandible
Insertion: skin of chin

12. Risorius Action: Draws corner of mouth laterally
Origin: fascia of masseter
Insertion: corner of mouth

13. Muscles of Mastication

14. Masseter Action: Elevates mandible to close jaw; protrudes mandible
Origin: Zygomatic arch
Insertion: lateral surface of the mandibular ramus

15. Temporalis Action: Elevates and retracts mandible to close jaw
Origin: Temporal bone
Insertion: coronoid process of mandible

16. SUPERFICIAL MUSCULATURE OF THE NECK

17. Sternocleidomastoid
Action: Flexion and lateral flexion of neck; rotates head so that face is turned superiorly and to the opposite side.
Origin: Manubrium; medial third of clavicle
Insertion: Mastoid process

18. Omohyoid Action: Depresses and retracts hyoid bone Superior belly
Origin: Clavicle and first rib
Insertion: hyoid bone
Inferior belly
Origin: superior margin of scapula
Insertion: clavicle and first rib

19. Thyrohyoid Action: Depresses hyoid bone; elevates larynx
Origin: thyroid cartilage of larynx
Insertion: hyoid bone

20. Sternohyoid Action: Depresses larynx and hyoid bone during swallowing.
Origin: Manubrium
Insertion: Hyoid bone

21. Stylohyoid
Action: Elevates and retracts hyoid bone during swallowing and speaking
Origin: Styloid process of temporal bone
Insertion: hyoid bone

22. Mylohyoid
Action: Elevates hyoid bone and floor of mouth during swallowing and speaking
Origin: Inferior margin of mandible
Insertion: Hyoid bone

23. Digastric Anterior Belly
Action: Elevates hyoid bone and base of tongue, depresses mandible
Origin: inferior margin of mandible
Insertion: Hyoid bone

24. Digastric Posterior Belly
Action: Moves hyoid bone back
Origin: mastoid process
Insertion: Hyoid bone

25. MUSCLES OF THE NECK & BACK

26. Scalenes Anterior Action: Laterally flexes of neck
Elevates rib 1 during forced inspiration
Origin: transverse processes of cervical vertebrae.
Insertion: 1st rib

27. Scalenes Middle Action: Lateral flexion of neck
Elevates rib 1 during forced inspiration
Origin: transverse processes of cervical vertebrae.
Insertion: 1st rib

28. Scalenes Posterior Action: Elevates 2nd rib,
Elevates rib 2 during forced inspiration
Origin: transverse processes of cervical vertebrae.
Insertion: 2nd rib

29. Levator Scapula
Action: Elevates scapula and inferior rotation of scapula
Origin: Transverse processes of superior four cervical vertebrae
Insertion: medial border of scapula near superior angle

30. Rhomboid Minor Action: Adducts scapula and performs downward rotation
Origin: Ligamentum nuchae; spinous processes of vertebrae C7 and T1
Insertion: Medial border of scapula

31. Rhomboid Major Action: Adducts scapula and performs downward rotation
Origin: Spinous processes of vertebrae T2-T5.
Insertion: Medial border of scapula

32. Trapezius Action: Elevate, retracts and depresses scapula.
Origin: Posterior surface of occipital bone; ligamentu nuchae; spinous processes of thoracic vertebrae.
Insertion: Lateral third of clavicle; acromion; spine of scapula

33. Latissimus Dorsi
Action: Extension, adduction and medial rotation of arm
Origin: Spinous processes of vertebrae T6-T12; thoracolubar fascia; iliac crest; inferior three ribs
Insertion: Intertubercular groove of humerus

34. Erector Spinae Action: Extension of vertebral column Iliocostalis
Spinalis
Longissimus
Origin: Thoracolumbar fascia; posterior surface of lacrum; iliac crest; spinous processes of T11-T12 and L1-L5.

35. Erector spinae Insertion:
Iliocostalis: angles of ribs and transvers processes of C4-C6
Longissimus: transverse processes of thoracic and cervical vertebrae, etc.
Spinalis: spinous processes of thoracic and cervical vertebrae

36. Inferior Serratus Posterior
Aka: serratus posterior inferior
Action: Pulls ribs down, resisting pull of the diaphragm
Origin: spinous processes of the lower two thoracic and upper two or three lumbar vertebrae
Insertion: lower borders of the bottom four ribs

37. Splenius
Action: Extension of head and neck; lateral flexion and rotation of the head and neck
Origin: Spinous processes of inferior cervical and superior thoracic vertebrae
Insertion: mastoid process, occipital bone, and transverse processes of superior cervical vertebrae

38. Internal Intercostal
Action: Depresses rib cage during forced expiration
Origin: Superior border of inferior rib
Insertion: Inferior border of superior rib

39. External Intercostal Action: Elevates rib cage during inspiration
Origin: Inferior border of superior rib
Insertion: Superior border of inferior rib

40. Serratus Anterior Action: Holds scapula to chest wall,
Protraction and superior rotation of scapula
Origin: External surfaces of ribs 1-8
Insertion: Medial border of scapula

41. Pectoralis Minor
Action: Draws scapula down and forward and elevates ribs
Origin: External surfaces of ribs 3-5
Insertion: Coracoid process of scapula

42. Pectoralis Major
Action: Flexes, adducts, and medially rotates humerus, draws body upward in climbing
Origin: Medial half of clavicle; sternum; costal cartilages of ribs 1-6
Insertion: lateral lip of intertubercular groove on humerus

43. Subscapularis Action: Adduction and medial rotation of arm.
Origin: Subscapular fossa of scapula
Insertion: lesser tubercle of humerus

44. Supraspinatus Action: Abduction of arm
Origin: supraspinous fossa of scapula
Insertion: Greater tubercle of humerus

45. Infraspinatus Action: Lateral rotation of arm
Origin: Infraspinous fossa of scapula
Insertion: Greater tubercle of humerus

46. Teres minor Action: Lateral rotation of the arm
Origin: Lateral border of scapula
Insertion: Greater tubercle of humerus

47. Teres major Action: Extension, adduction and medial rotation of arm
Origin: Scapula, near inferior angle
Insertion: medial lip of intertubercular groove of the humerus

48. Deltoid Action: Anterior fibers: medial rotation and flexion of arm
Middle fibers: abduction of arm
Posterior fibers: lateral rotation and extension of arm

49. Deltoid
Origin: Lateral third of clavicle; acromion process; spine of scapula
Insertion: Deltoid tuberosity of humerus

50. Diaphragm
Action: Increases volume of thoracic cavity by pulling central tendon inferiorly
Origin: Xiphoid process and inferior six ribs
Insertion: central tendon of diaphragm

51. MUSCLES OF THE ANTERIOR ABDOMINAL WALL

52. Rectus Abdominis
Action: Tenses abdominal wall and flexes vertebral column
Origin: Pubic crest; pubic symphysis
Insertion: Xiphoid process, costal cartilages of ribs 5-7

53. External Abdominal Oblique
Action: Compresses abdomen, contralaterally rotates and flexes vertebral column
Origin: External surfaces of inferior 8 ribs.
Insertion: Linea alba; pubic crest; pubic tubercle; iliac crest

54. Internal Abdominal Oblique
Action: Compresses abdomen, ipsilaterally rotates and flexes vertebral column
Origin: Thoracolumbar fascia; iliac crest; inguinal ligament
Insertion: Linea alba; pubic crest; inferior three or four ribs

55. Transverse Abdominis Action: Compresses abdomen
Origin: Thoracolumbar fascia; inguinal ligament; costal cartilages of inferior six ribs; iliac crest
Insertion: linea alba; pubic crest

56. Biceps brachii
Action: Flexion and supination of forearm; flexion of arm
Origin: Long head: superior margin of glenoid fossa of scapula
Short head: coracoid process of scapula
Insertion: radial tuberosity of radius

57. Brachialis Action: Flexion of forearm
Origin: Anterior surface of humerus
Insertion: Coronoid process of ulna

58. Coracobrachialis Action: Flexion and adduction of arm
Origin: Coracoid process of scapula
Insertion: Medial surface of humerus

59. Triceps brachii
Long Head
Action: Extension of forearm; long head extends and adducts arm
Origin: Long head: inferior margin of glenoid fossa
Lateral head: posterior surface of humerus
Medial head: posterior surface inferior to lateral head
Insertion: Olecranon process of ulna
Lateral Head

60. The End
The End