Muscular System

Front 1

Frontalis

Back 1

Elevates eyebrows; wrinkles skin of forehead

Front 2

Occipitalis

Back 2

Retracts scalp; fixes galea aponeurotica so the frontalis can act on eyebrows

Front 3

Orbicularis Oculi

Back 3

Closes eye in blinking, squinting, and sleep

Front 4

Orbicularis Oris

Back 4

Purses lips; kissing muscle

Front 5

Levator Palpebrae Superioris (O, I)

Back 5

A: Elevates upper eyelid; opens eye
O: Lesser wing of sphenoid
I: Upper eyelid

Front 6

Nasalis

Back 6

Widens nostrils

Front 7

Levator Anguli Oris

Back 7

Elevates angle of mouth; smiling muscle

Front 8

Depressor Anguli Oris

Back 8

Draws angle of mouth laterally and downward in opening of mouth and frowning

Front 9

Zygomaticus (Major and Minor) (O, I)

Back 9

A: Draws angle of mouth up and laterally as in smiling, sneering or laughing
O: Zygomatic Bone
I: Skin and muscles of mouth

Front 10

Platysma

Back 10

Draws lower lip and angle of mouth downward in expressions of horror or surprise

Front 11

Buccinator

Back 11

Compresses cheek against teeth and gums; expels liquid and air

Front 12

Temporalis (O, I)

Back 12

A: Elevation, retraction and lateral and medial excursion of the mandible
O: Squamous region of temporal bone
I: Coronoid process of mandible

Front 13

Masseter (O, I)

Back 13

A: Elevation of the mandible
O: Zygomatic Arch
I: Mandibular angle and lateral ramus of mandible

Front 14

Sternocleidomastoid (O, I)

Back 14

A: Unilateral action tilts head slightly upward and toward the opposite side; bilateral action flexes the head forward
O: Manubrium of sternum; medial 1/3 of clavicle
I: Mastoid process; lateral half of superior nuchal line

Front 15

Scalenes Group (O, I)

Back 15

A: Unilateral action tilts head in the same direction and rotates the face in the opposite direction; bilateral action flexes neck forward
O: Transverse processes of C1-C7
I: Ribs 1-2

Front 16

Splenius Capitis

Back 16

Unilateral action tilts and rotates head in the same direction; bilateral action extends head

Front 17

Trapezius (O, I)

Back 17

A: Extension and lateral flexion of neck; elevation, retraction, lateral rotation, and depression of the scapula
O: external occipital protuberance; superior nuchal line; spinous processes of vertebrae C7-T3
I: Acromion and spine of scapula; lateral 1/3 of clavicle

Front 18

Rhomboideus Major

Back 18

Retraction, elevation and medial rotation of scapula

Front 19

Pectoralis Minor (O, I)

Back 19

A: Protraction of scapula
O: Ribs 3-5
I: Coracoid process of scapula

Front 20

Serratus Anterior

Back 20

Lateral rotation and protraction of scapula

Front 21

Errector Spinae Group (Iliocostals, Longissimus, Spinalis) (O, I)

Back 21

A: Extension and lateral flexion of vertebral column
O: Nuchal ligament; ribs 3-12; thoracic and lumbar vertebrae; medial sacral crests
I: Mastoid process; cervical and thoracic vertebrae; all ribs

Front 22

Pectoralis Major (O, I)

Back 22

A: Flexion, adduction and medial rotation of arm at the shoulder
O: Medial 1/2 of clavicle; lateral margin of sternum; costal cartilages 1-7
I: Intertubercular sulcus of humerus

Front 23

Latissimus Dorsi (O, I)

Back 23

A: Adduction and medial rotation of the arm at the shoulder; extension of arm at shoulder
O: T7-L5; Ribs 9-12; Iliac Crest
I: Intertubercular sulcus of humerus

Front 24

Deltoid (O, I)

Back 24

A: Abduction, flexion, extension, medial rotation and lateral rotation of the arm at the shoulder
O: Acromion and spine of scapula
I: Deltoid tuberosity of humerus

Front 25

Supraspinatus

Back 25

Abduction of the arm at the shoulder

Front 26

Infraspinatus

Back 26

Lateral rotation of the arm at the shoulder

Front 27

Teres Minor

Back 27

Lateral rotation of the arm at the shoulder

Front 28

Subscapularis

Back 28

Medial rotation of the arm at the shoulder

Front 29

Coracobrachialis

Back 29

Flexion and medial rotation of the arm at the shoulder

Front 30

Teres Major

Back 30

Extension and medial rotation of the arm at the shoulder

Front 31

Brachialis

Back 31

Flexion of the elbow

Front 32

Biceps Brachii (O, I)

Back 32

A: Supination of forearm; flexion of the elbow and shoulder
O: Glenoid cavity (long head); Coracoid process of the scapula (short head)
I: Radial tuberosity

Front 33

Triceps Brachii (O, I)

Back 33

A: Extension of the elbow and adduction of the arm at the shoulder
O: Glenoid cavity and joint capsule (long head); posterior surface of head of humerus (lateral head); posterior surface of humeral shaft (medial head)
I: Olecranon process of ulna

Front 34

Brachioradialis (O, I)

Back 34

A: Flexion of the elbow
O: Lateral supracondylar ridge of humerus
I: Lateral surface of radius near styloid process

Front 35

Pronator Quadratus

Back 35

Pronation of the forearm

Front 36

Pronator Teres

Back 36

Pronation of the forearm

Front 37

Flexor Carpi Radialis

Back 37

Anterior and radial flexion of wrist

Front 38

Flexor Carpi Ulnaris

Back 38

Anterior and ulnar flexion of wrist

Front 39

Palmaris Longus

Back 39

Anchors skin and fascia of the palm

Front 40

Flexor Digitorum Profundus

Back 40

Flexion of wrist; flexion of interphalangeal joints II-V

Front 41

Flexor Pollicus Longus

Back 41

Flexion of interphalangeal joints of the thumb

Front 42

Extensor Carpi Radialis Longus and Brevus

Back 42

Extension and radial flexion of wrist

Front 43

Extensor Digitorum

Back 43

Extension of wrist; extension of metacarpophalangeal and interphalangeal joints

Front 44

Extensor Carpi Ulnaris

Back 44

Extension and ulnar flexion of wrist

Front 45

Adductor Pollicus

Back 45

Draws thumb toward palm as in "gripping"

Front 46

Abductor Pollicus Longus and Brevis

Back 46

Abduction of thumb in frontal and sagittal plane

Front 47

Extensor Pollicus Longus and Brevis

Back 47

Extension of thumb

Front 48

Flexor Pollicus Brevis

Back 48

Flexion of thumb

Front 49

Opponens Pollicus

Back 49

Opposition of thumb

Front 50

Diaphragm

Back 50

Prime mover of inspiration; compresses abdomen

Front 51

External Intercostals

Back 51

Elevation of ribs for inspiration

Front 52

Internal Intercostals

Back 52

Depression of the ribs for forced expiration

Front 53

External Abdominal Obliques (O, I)

Back 53

A: Compresses abdomen; stabilizes vertebral column during lifting; unilateral contraction causes contralateral rotation
O: Ribs 5-12
I: Iliac crest; pubic symphysis and superior ramus of pubis

Front 54

Internal Abdominal Obliques

Back 54

Compresses abdomen; stabilizes vertebral column during lifting; unilateral contraction causes ipsilateral rotation

Front 55

Tranverse Abdominal

Back 55

Compresses abdomen

Front 56

Rectus Abdominis (O, I)

Back 56

A: Flexion of vertebral column
O: Pubic symphysis and superior ramus of pubis
I: Xiphoid process; costal cartilages 5-7

Front 57

Ilipsoas Group (Iliacus and Psoas Major) (O, I)

Back 57

A: Flexion of thigh at hip when trunk is fixed; flexion of trunk when hip is fixed
O: Iliac crest and fossa; superior region of sacrum (Iliacus); bodies and intervertebral discs of T12-L5 and the tranverse processes of lumbar vertebrae (psoas)
I: Lesser trochanter of femur

Front 58

Tensor Fasciae Lata (O, I)

Back 58

A: Extension and lateral rotation of knee; abduction and medial rotation of thigh at hip
O: Iliac crest and fascia lata
I: Lateral condyle of tibia via iliotibial band

Front 59

Gluteus Maximus (O, I)

Back 59

A: Extension and abduction of thigh at hip; elevation of trunk
O: Posterior surface of ilium, coccyx and sacrum
I: Gluteal tuberosity of femus; lateral condyle of tibia via iliotibial band

Front 60

Gluteus Medius

Back 60

Abduction and medial rotation of thigh at hip

Front 61

Piriformis

Back 61

Lateral rotation and extension of thigh at hip

Front 62

Quadratus Femoris

Back 62

Lateral rotation and extension of thigh at hip

Front 63

Adductor Brevis (O, I)

Back 63

A: Adduction of thigh at hip
O: body and inferior ramus of pubis
I: linea aspera of femur

Front 64

Adductor Longus (O, I)

Back 64

A: Adduction, medial rotation and flexion of thigh at hip
O: Body and inferior ramus of pubis
I: linea aspera of femur

Front 65

Adductor Magnus (O, I)

Back 65

A: Adduction, medial rotation and extension of thigh at hip
O: Inferior ramus of pubis; ischial tuberosity
I: Linea aspera, gluteal tuberosity of femur

Front 66

Gracilis

Back 66

Flexion and medial rotation of tibia at knee

Front 67

Pectineus

Back 67

Flexion and adduction of thigh at hip

Front 68

Rectus Femoris (O, I)

Back 68

A: Extension of knee; flexion of thigh at hip
O: Anterior superior spine of ilium; superior margin of acetabulum
I: Patella; tibial tuberosity; lateral and medial condyles of tibia

Front 69

Vastus Lateralis (O, I)

Back 69

A: Extension of knee
O: Greater trochanter of femur; gluteal tuberosity and linea aspera of femur
I: Patella; tibial tuberosity; lateral and medial condyles of tibia

Front 70

Vastus Medialis (O, I)

Back 70

A: Extensio of knee
O: Intertrochanteric line of femur; linea aspera
I: Patella; tibial tuberosity; lateral and medial condyles of tibia

Front 71

Vastus Intermedius (O, I)

Back 71

A: Extension of knee
O: Anterior and lateral surfaces of femoral shaft
I: Patella; tibial tuberosity; lateral and medial condyles of tibia

Front 72

Sartorius

Back 72

Extension of knee and hip; abduction and lateral rotation of thigh at hip

Front 73

Biceps Femoris (O, I)

Back 73

A: Flexion of knee; extension of thigh at hip; elevation of trunk
O: Ishcial tuberosity (long head); linea aspera (short head)
I: Head of fibula

Front 74

Semitendinosus (O, I)

Back 74

A: Flexion of knee; medial roation of tibia at knee when flexed
O: Ischial tuberosity
I: Medial surface of upper tibia

Front 75

Semimembranosus (O,I)

Back 75

A: Flexion of knee; medial rotation of tibia at knee when flexed
O: Ischial tuberosity
I: Medial and lateral condyle of femur; popliteal ligament

Front 76

Popliteus

Back 76

Medial rotation of tibia at knee when flexing the knee

Front 77

Gastrocnemius (O, I)

Back 77

A: Plantar flexion of foot
O: Condyles and popliteal surface of tibia
I: Calcaneus

Front 78

Tibialis Anterior (only O, I)

Back 78

O: Lateral condyle and lateral margin of proximal 1/2 of tibia; interosseous membrane
I: Medial cuneiform; metatarsal I

Front 79

Soleus

Back 79

Plantar flexion of foot

Front 80

Peroneus Longus and Brevis

Back 80

Eversion of foot; maintains concavity of foot during tiptoeing

Front 81

Tibialis Posterior

Back 81

Inversion of foot; plantar flexion of foot

Front 82

Extensor Digitorum Longus

Back 82

Extension of interphalangeal joints of toes; dorsiflexion of foot

Front 83

Extensor Digitorum Brevis

Back 83

Extension of interphalangeal joints if toes

Front 84

Extensor Hallucis Longus and Brevis

Back 84

Extension of big toe; dorsiflexion of foot

Front 85

Flexor Digitorum Longus

Back 85

Flexion of interphalangeal joints of toes

Front 86

Flexor Digitorum Brevis

Back 86

Flexion of interphalaneal joints of toes

Front 87

Flexor Hallucis Longus and Brevis

Back 87

Flexion of big toe

Front 88

Lateral Rectus

Back 88

Moves eye laterally

Front 89

Medial Rectus

Back 89

Moves eye medially

Front 90

Superior Rectus

Back 90

Elevates eye and turns it medially

Front 91

Inferior Rectus

Back 91

Depresses eye and turns it medially

Front 92

Inferior Oblique

Back 92

Elevates eye and turns it laterally

Front 93

Superior Oblique

Back 93

Depresses eye and turns it laterally

Front 94

Medial Pterygoid

Back 94

Elevation, protraction and lateral and medial excursion of mandible

Front 95

Lateral Pterygoid

Back 95

Depression (open mouth), protraction, medial and lateral excursion of mandible

Front 96

Levator ani

Back 96

Reinforces external urethral and anal sphincters; supports and maintains pelvic viscera; elevates to assist in defecation

Front 97

Coccygeus

Back 97

Reinforces external urethral and anal sphincters; supports and maintains pelvic viscera; elevates to assist in defecation

Front 98

External Urethral Sphincter

Back 98

Retains urine in urinary bladder until voluntary expulsion

Front 99

External Anal Sphincter

Back 99

Retains feces in rectum until voluntarily voided

Front 100

Ischiocavernosus

Back 100

Maintains erection via compression

Front 101

Bulbospongiosus

Back 101

Aids in erection; expels urine, semen (in males), vestibular glands (females)

Front 102

Rhomboideus Minor

Back 102

Acts on scapula

Front 103

Levator Scapulae

Back 103

Elevates scapula