Lab 11 Group I - Portland Community College

Lab Activity 11: Group I

Muscles

Martini Chapter 11

Portland Community CollegeBI 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

Frontalis

• Origin: Epicranial

aponeurosis

• Insertion: Skin

over forehead

• Action: Elevates

eyebrows and

wrinkles skin of

forehead

Epicranial

Aponeurosis

4

Occipitalis

• Origin: Occipital

and temporal bones

• Insertion: Epicranial

aponeurosis

• Action: Fixes

epicranial

aponeurosis and

pulls scalp

posteriorly

5

Orbicularis Oculi

• Origin: Medial orbital

margin and zygomatic

bone

• Insertion: Skin

surrounding eye

• Action: Closes eyelids

and depresses skin of

forehead

6

Temporalis

• Origin: Temporal

fossa

• Insertion:

Coronoid process

of mandible

• Action: Elevates

and retracts

mandible

7

Masseter

• Origin:

Zygomatic

process and arch

• Insertion: Angle

and ramus of

mandible

• Action: Elevates

mandible

8

Orbicularis Oris

• Origin: By muscular

skips to surround

muscles

• Insertion: Muscles

interlace to surround

mouth

• Action: Closes and

purses lips

9

• Origin: Zygomatic

arch

• Insertion: Corner of

mouth

• Action: Elevates

corner of mouth

Zygomaticus Major

10

• Origin: Fascia of

masseter

• Insertion: Corner of

mouth

• Action: Draws corner

of mouth laterally

Risorius

11

• Origin: Medial tip of

suprascapular notch

• Insertion: Body of

hyoid bone

• Action: Depresses

hyoid bone

Omohyoid

12

• Origin: Posterior

surface of

manubrium, and

medial clavicle

• Insertion: Hyoid

bone

• Action: Depresses

hyoid bone

Sternohyoid

13

• Origin: Mylohyoid

line of mandible

• Insertion: Hyoid bone

• Action: Elevates

hyoid bone and floor

of mouth, depresses

mandible

Mylohyoid

14

• Origin: Lower border

of mandible near

midline

• Insertion:

Intermediate tendon

• Action: Elevates

hyoid bone and base

of tongue, depresses

mandible

Digastric

Anterior Belly

15

• Origin: Mastoid

notch of temporal

bone

• Insertion:

Intermediate tendon

• Action: Moves hyoid

bone back

Digastric

Posterior Belly

16

• Origin: Manubrium and medial third of clavicle

• Insertion: Mastoid process

• Action: Rotates head to opposite side, extends head, and flexes vertebral column

Sternocleidomastoid

17

Trapezius

• Origin: External occipital

protuberance, superior

nuchal line and spinous

process of C7-T12

• Insertion: Anterior border

of scapular spine, acromion

process, lateral third of

clavicle

• Action: Elevates, adducts,

and depresses scapula

18

Latissimus Dorsi

• Origin: Spinous processes of lower 6 thoracic vertebrae, thoracolumbar fascia, crest of ilium

• Insertion: Intertubercular groove of humerus

• Action: Extends, rotates humerus medially, draws shoulder down and backward

19

• Origin: Transverse

processes of C1-4

• Insertion: Superior angle

spine of scapula

• Action: Elevates scapula

Levator Scapula

20

• Origin: Spinous process of T

1-5and

supraspinous ligament

• Insertion: Medial border below spine of scapula

• Action: Adducts scapula and performs downward rotation

Rhomboid Major

21

• Origin: Spinous

process of C7-T

1

• Insertion: Medial

border of scapula at

base of spine

• Action: Adducts

scapula and performs

downward rotation

Rhomboid Minor

22

• Origin: Lateral surface

of upper 8 ribs

• Insertion: Anterior lip

of medial border of

scapula

• Action: Holds scapula

to chest wall, medially

rotates scapula in

abducting or extending

humerus

Serratus Anterior

23

• Origin: Sacrum, iliac crest, spinous processes of lumbar vertebrae and T11,12

• Insertion: Angles of the ribs. Spinous & Transverse processes of vertebrae

• Action: Extension of vertebral column

Erector Spinae

24

• Origin: Iliolumbar ligament and crest of ilium

• Insertion: Lower border of 12th rib, transverse process of upper lumbar vertebrae

• Action: Depresses rib cage inferiorly and laterally flexes trunk

Quadratus

Lumborum

25

• Origin: Transverse

processes of C3-C

6

• Insertion: 1st rib

• Action: Elevates 1st

rib, flexes neck

forward and laterally,

rotates neck

Scalenes

Anterior

26

• Origin: Transverse

processes of C2-C

7

• Insertion: 1st rib

• Action: Elevates 1st

rib, flexes neck

forward and laterally,

rotates neck

Scalenes

Middle

27

• Origin: Transverse

processes of C4-C

6

• Insertion: 2nd rib

• Action: Elevates 2nd

rib, flexes neck

laterally, slightly

rotates neck

Scalenes

Posterior

28

• Origin: Inferior

border of rib above

• Insertion: Superior

border of rib below

• Action: Elevates rib

cage during

inspiration

External Intercostal

29

• Origin: Superior

border of rib below

• Insertion: Inferior

border of rib above

• Action: Depresses rib

cage during expiration

Internal Intercostal

30

Pectoralis Major

• Origin: Medial half of

clavicle, sternum, costal

cartilages, aponeurosis of

external abdominal oblique

• Insertion: Intertubular groove

of humerus

• Action: Flexes, adducts, and

medially rotates humerus,

draws body upward in

climbing

31

• Origin: Anterior

surface of ribs 3 to 5

• Insertion: Coracoid

process of scapula

• Action: Draws

scapula down and

forward and elevates

ribs

Pectoralis Minor

32

• Origin: Pubis symphysis and crest of pubis

• Insertion: Xiphoid process and cartilages of ribs 5 to 7

• Action: Tenses abdominal wall and flexes vertebral column

Rectus Abdominus

33

• Origin: External

surface of lower 8 ribs

• Insertion: Anterior

half of iliac crest and

linea alba

• Action: Compresses

abdomen,

contralaterally rotates

and flexes vertebral

column

External Abdominal Oblique

34

• Origin: Lateral half of inguinal ligament, anterior iliac crest and thoracolumbar fascia

• Insertion: Lower four ribs, linea alba and by conjoined tendon to pubis

• Action: Compresses abdomen, ipsilaterally rotates and flexes vertebral column

Internal Abdominal Oblique

35

• Origin: Lateral third of inguinal ligament, anterior iliac crest, and thoracolumbar fascia

• Insertion: Linea alba, and by conjoined tendon to pubis

• Action: Compresses abdomen

Transverse Abdominis

36

The End