Human Anatomy & Physiology; Chapter 10 Muscles

Front 1

Orbicularis oculi

Back 1

Description:
Thin, tripartite sphincter muscle of the eyelid; surrounds the rim of the orbit

Front 2

Orbicularis oculi

Back 2

Origin (O):
frontal and maxillary bones and ligaments around the orbit
Insertion (I):
tissue of the eyelid

Front 3

Obicularis oculi

Back 3

Action:
CLOSES EYE; various parts can be activated individually by blinking, squinting, and draws eyebrows inferiorly

Front 4

Orbicularis oculi

Back 4

Nerve Supply:
facial nerve

Front 5

Zygomaticus

Back 5

Description:
Muscle pair extending diagonally from cheekbone to corner of the mouth

Front 6

Zygomaticus

Back 6

Origin (O):
zygomatic bone
Insertion (I):
skin and muscle at the corner of the mouth

Front 7

Zygomaticus

Back 7

Action:
RAISES LATERAL CORNERS OF MOUTH UPWARD (*smiling muscle)

Front 8

Zygomaticus

Back 8

Nerve Supply:
facial nerve

Front 9

Risorius

Back 9

Description:
slender muscle inferior and lateral to zygomaticus

Front 10

Risorius

Back 10

Origin (O):
lateral fascia associated with masseter muscle
Insertion (I):
skin at angle of mouth

Front 11

Risorius

Back 11

Action:
DRAWS CORNER OF LIP LATERALLY; tenses lips; synergist of zygomaticus

Front 12

Risorius

Back 12

Nerve Supply:
facial nerve

Front 13

Levator labii superioris

Back 13

Description:
thin muscle between orbicularis oris and inferior eye margin

Front 14

Levator labii superioris

Back 14

Origin (O):
zygomatic bone and infraorbital margin of maxilla
Insertion (I):
skin and muscle of upper lip

Front 15

Levator labii superioris

Back 15

Action:
OPENS LIPS; raises and furrows the upper lip

Front 16

Levator labii superioris

Back 16

Nerve Supply:
facial nerve

Front 17

Depressor labii inferioris

Back 17

Description:
small muscle running from mandible to lower lip

Front 18

Depressor labii inferioris

Back 18

Origin (O):
body of mandible lateral to its midline
Insertion (I):
skin and muscle of lower lip

Front 19

Depressor labii inferioris

Back 19

Action:
DRAWS LOWER LIP INFERIORLY
(*pouting muscle)

Front 20

Depressor labii inferioris

Back 20

Nerve Supply:
facial nerve

Front 21

Depressor anguli oris

Back 21

Description:
small muscle running from mandible to lower lip

Front 22

Depressor anguli oris

Back 22

Origin (O):
body on mandible below incisors
Insertion (I):
skin and muscle at the angle of the mouth below insertion of zygomaticus

Front 23

Depressor anguli oris

Back 23

Action:
DRAWS CORNERS OF MOUTH DOWNWARD AND LATERALLY (*tragedy mask); zygomaticuz and antagonist

Front 24

Depressor anguli oris

Back 24

Nerve Supply:
facial nerve

Front 25

Orbicularis oris

Back 25

Description:
complicated, multilayered muscle of the lips with fibers that run in many different directions; most run circularly

Front 26

Orbicularis oris

Back 26

Origin (O):
arises indirectly from maxilla and mandible; fibers blended with fibers of other fibers of other facial muscles associated with the lips
Insertion (I):
encircles mouth; inserts into muscle and skin at angles of mouth

Front 27

Orbicularis oris

Back 27

Action:
CLOSES LIPS; purses and protrudes lips; *kissing and whistling muscle

Front 28

Orbicularis oris

Back 28

Nerve Supply:
facial nerve

Front 29

Mentalis

Back 29

Description:
one of the muscle pair forming a V-shaped muscle mass on chin

Front 30

Mentalis

Back 30

Origin (O):
mandible below incisors
Insertion (I):
skin of chin

Front 31

Mentalis

Back 31

Action:
WRINKLES CHIN; protrudes lower lip

Front 32

Mentalis

Back 32

Nerve Supply:
facial nerve

Front 33

Buccinator

Back 33

Description:
thin, horizontal cheek muscle; principal muscle of cheek; deep to masseter

Front 34

Buccinator

Back 34

Origin (O):
molar region of maxilla and mandible
Insertion (I):
orbicularis oris

Front 35

Buccinator

Back 35

Action:
COMPRESSES CHEEK; trampoline-like action holds food between teeth during chewing; draws corner of mouth laterally; well developed in nursing infants

Front 36

Buccinator

Back 36

Nerve Supply:
facial nerve

Front 37

Platysma

Back 37

Description:
unpaired, thin, sheetlike superficial neck muscle; not strictly a head muscle, but plays a role in facial expression

Front 38

Platysma

Back 38

Origin (O):
fascia of chest (over pectoral muscles and deltoid)
Insertion (I):
lower margin of mandible, and skin and muscle at corner of mouth

Front 39

Platysma

Back 39

Action:
TENSES SKIN OF NECK; helps depress mandible; pulls lower lip back and down

Front 40

Platysma

Back 40

Nerve Supply:
facial supply

Front 41

Masseter

Back 41

Description:
powerful muscle that covers lateral aspect of mandibular ramus

Front 42

Masseter

Back 42

Origin (O):
zygomatic arch and zygomatic bone
Insertion (I):
angle and ramus of mandible

Front 43

Masseter

Back 43

Action:
PRIME MOVER OF JAW CLOSURE; elevates mandible

Front 44

Masseter

Back 44

Nerve Supply:
Trigeminal nerve (cranial V)

Front 45

Temporalis

Back 45

Description:
fan-shaped muscle that covers parts of the temporal, frontal, and parietal bones

Front 46

Temporalis

Back 46

Origin (O):
temporal fossa
Insertion (I):
coronoid process of mandible via a tendon that passes deep to zygomatic arch

Front 47

Temporalis

Back 47

Action:
CLOSES JAW; elevates and retracts mandible; maintains position of the mandible at rest; deep anterior part may hepl protract mandible

Front 48

Temporalis

Back 48

Nerve Supply:
Trigeminal nerve

Front 49

Medial pterygoid

Back 49

Description:
deep two-headed muscle that runs along internal surface of mandible and is largely concealed by that bone

Front 50

Medial pterygoid

Back 50

Origin (O):
medial surface of lateral pterygoid plate of sphenoid bone, maxilla, and palatine bone
Insertion (I):
medial surface of mandible near its angle

Front 51

Medial pterygoid

Back 51

Action:
ACTS WITH THE LATERAL PTERYGOID MUSCLE TO PROTRUDE (PROTRACT) MANDIBLE AND TO PROMOTE SIDE-TO-SIDE (GRINDING) MOVEMENTS; synergist of temporalis and masseter muscles in elevation of the mandible

Front 52

Medial pterygoid

Back 52

Nerve Supply:
Trigeminal nerve

Front 53

Lateral pterygoid

Back 53

Description:
Deep two-headed muscle; lies superior to medial pterygoid muscle

Front 54

Lateral pterygoid

Back 54

Origin (O):
greater wing and lateral pterygoid plate of sphenoid bone
Insertion (I):
condyle of mandible and capsule of temporomandibular joint

Front 55

Lateral pterygoid

Back 55

Action:
PROVIDES FORWARD SLIDING AND SIDE-TO-SIDE GRINDING MOVEMENTS OF THE LOWER TEETH; protrudes mandible (pulls it anteriorly)

Front 56

Lateral pterygoid

Back 56

Nerve Supply:
Trigeminal nerve

Front 57

Genioglossus

Back 57

Description:
fan-shaped muscle; forms bulk of inferior part of tongue; its attachment to mandible prevents tongue from falling backward and obstructing respiration

Front 58

Genioglossus

Back 58

Origin (O):
internal surface of mandible near symphysis
Insertion (I):
inferior aspect of the tongue and body of hyoid bone

Front 59

Genioglossus

Back 59

Action:
PROTRACTS TONGUE; can depress or act in concert with other extrinsic muscles to retract tongue

Front 60

Genioglossus

Back 60

Nerve Supply:
Hypoglossal nerve (cranial XII)

Front 61

Hypoglossus

Back 61

Description:
flat, quadrilateral muscle

Front 62

Hypoglossus

Back 62

Origin (O):
body and greater horn of hyoid bone
Insertion (I):
inferolateral tongue

Front 63

Hypoglossus

Back 63

Action:
DEPRESSES TONGUE and draws its sides downward

Front 64

Hypoglossus

Back 64

Nerve Supply:
Hypoglossal nerve

Front 65

Styloglossus

Back 65

Description:
slender muscle running superiorly to and at right angles to hypoglossus

Front 66

Styloglossus

Back 66

Origin (O):
styloid process of temporal bone
Insertion (I):
inferolateral tongue

Front 67

Styloglossus

Back 67

Action:
RETRACTS (AND ELEVATES) TONGUE

Front 68

Styloglossus

Back 68

Nerve Supply:
hypoglossal nerve

Front 69

Suprahyoid Muscle

Back 69

Description:
muscles that help form floor of oral cavity, anchor tongue, elevate hyoid, and move larnyx superiorly during swallowing; lie superior to hyoid bone

Front 70

Digastric

Back 70

Description:
consists of two bellies united by an intermediate tendon, forming a V shape under the chin

Front 71

Digastric

Back 71

Origin (O):
lower margin of mandible (anterior belly) and mastoid process of the temporal bone (posterior belly)
Insertion (I):
by a connective tissue

Front 72

Digastric

Back 72

Action:
OPENS MOUTH AND DEPRESS MANDIBLE; acting in concert, the digastric muscles elevate hyoid bone and steady it during swallowing and speech

Front 73

Digastric

Back 73

Nerve Supply:
mandibular branch of trigeminal nerve (cranial V) for the anterior belly; facial nerve (cranial VII) for posterior belly

Front 74

Stylohyoid

Back 74

Description:
slender muscle below angle of jaw; parallels posterior belly of digastric muscle

Front 75

Stylohyoid

Back 75

Origin (O):
styloid process of temporal bone
Insertion (I):
hyiod bone

Front 76

Stylohyoid

Back 76

Action:
ELEVATES AND RETRACTS HYOID, elongating the floor of mouth during swallowing

Front 77

Stylohyoid

Back 77

Nerve Supply:
facial nerve

Front 78

Mylohyoid

Back 78

Description:
flat, triangular muscle just deep to the digastric muscle; this muscle pair forms a sling that forms the floor of the anterior mouth

Front 79

Mylohyoid

Back 79

Origin (O):
medial surface of mandible
Insertion (I):
hyoid bone and median raphe (a median strip of connective tissue between the the mylohyoid muscles)

Front 80

Mylohyoid

Back 80

Action:
ELEVATES HYOID BONE AND FLOOR OF MOUTH, enabling tongue to exert backward and upward pressure that forces food bolys into pharynx

Front 81

Mylohyoid

Back 81

Nerve Supply:
mandibular branch of trigeminal nerve

Front 82

Geniohyoid

Back 82

Description:
narrow hyoid muscle in contact with its partner medially; runs from chin to hyoid bone deep mylohyoid

Front 83

Geniohyoid

Back 83

Origin (O):
inner surface of mandibular symphysis
Insertion (I):
hyoid bone

Front 84

Geniohyoid

Back 84

Action:
PULLS HYOID BONE SUPERIORLY AND ANTERIORLY, shortening floor of the mouth and widening pharynx for receiving food

Front 85

Geniohyoid

Back 85

Nerve Supply:
First cervical spinal nerve via Hypoglossal nerve (cranial XII)

Front 86

Infrahyoid Muscles

Back 86

Description:
straplike muscles that depress the hyoid bone and larynx during swallowing and speaking

Front 87

Sternohyoid

Back 87

Description:
most medial muscle of the neck; thin, superficial except inferiorly where covered by sternocleidomastoid

Front 88

Sternohyoid

Back 88

Origin (O):
manubrium and medial end of clavicle
Insertion (I):
lover margin of bone

Front 89

Sternohyoid

Back 89

Action:
DEPRESSES LARYNX AND HYOID BONE IF MANDIBLE IS FIXED; may also flex skull

Front 90

Sternohyoid

Back 90

Nerve Supply:
Cervical spinal nerves 1-3 (C1-C3) though ansa cervical plexus)

Front 91

Sternothyoid

Back 91

Description:
lateral and deep to sternohyoid

Front 92

Sternothyoid

Back 92

Origin (O):
posterior surface of manubrium of sternum
Insertion (I):
thyroid cartilage

Front 93

Sternothyoid

Back 93

Action:
PULLS LARYNX AND HYOID BONE INFERIORLY

Front 94

Sternothyoid

Back 94

Nerve Supply:
As for sternohyoid

Front 95

Omohyoid

Back 95

Description:
straplike muscle with two bellies united by an intermediate tendon; lateral to sternohyoid

Front 96

Omohyoid

Back 96

Origin (O):
superior surface of scapula
Insertion (I):
hyoid bone, lower border

Front 97

Omohyoid

Back 97

Action:
DEPRESSES AND RETRACTS HYOID BONE

Front 98

Omohyoid

Back 98

Nerve Supply:
As for sternohyoid

Front 99

Thyrohyoid

Back 99

Description:
appears as a superior continuation of sternothyroid muscle

Front 100

Thyrohyoid

Back 100

Origin (O):
thyroid cartilage
Insertion (I):
hyoid bone

Front 101

Thyrohyoid

Back 101

Action:
DEPRESSES HYOID BONE OR ELEVATES LARYNX IF HYOID IS FIXED

Front 102

Thyrohyoid

Back 102

Nerve Supply:
First cervical nerve via hypoglossal nerve

Front 103

Pharyngeal Constrictor Muscles

Back 103

Description:
Composite of three paired muscles whose fibers run circularly in pharynx wall; superior muscle is innermost and inferior one is outermost; substantial overlap

Front 104

Pharyngeal Constrictor Muscles

Back 104

Origin (O):
attached anteriorly to mandible and medial pterygoid plate (superior), hyoid bone (middle), and laryngeal cartilages (inferior)
Insertion (I):
posterior median raphe of pharynx

Front 105

Pharyngeal Constrictor Muscles

Back 105

Action:
CONSTRICT PHARYNX DURING SWALLOWING, which propels a food bolus to esophagus (via a massagelike action called perstalis)

Front 106

Pharyngeal Constrictor Muscles

Back 106

Nerve Supply:
Pharyngeal plexus (branches of vagus nerve X)