Muscle Origins, Insertions, Actions - Head & Neck

Front 1

Longus colli

Back 1

Origin: lower anterior vertebral bodies and transverse processes
Insertion: anterior vertebral bodies and transverse processes several segments above
Action: flexes the head and neck

Front 2

Longus capitis

Back 2

Origin: upper anterior vertebral bodies and transverse processes
Insertion: anterior vertebral bodies and transverse processes several segments above
Action: flexes the head and neck

Front 3

Rectus capitis anterior

Back 3

Origin: anterior base of the transverse process of the atlas
Insertion: occipital bone anterior to foramen magnum
Action: flexes the head

Front 4

Rectus capitis lateralis

Back 4

Origin: transverse process of the atlas
Insertion: jugular process of the occipital bone
Action: bends the head laterally

Front 5

Anterior scalene

Back 5

Attachment A: anterior tubercles of transverse processes of C3-C6
Attachment B: 1st rib
Action:
if transverse process fixed:
elevates the ribs for respiration
if ribs fixed:
rotates to side opposite of contraction
laterally flexes to the contracted side
bilaterally flexes the neck

Front 6

Middle scalene

Back 6

Attachment A: transverse processes of all cervical vertebrae
Attachment B: 1st rib (behind anterior scalene)
Action:
if transverse process fixed:
elevates the ribs for respiration
if ribs fixed:
rotates to side opposite of contraction
laterally flexes to the contracted side
bilaterally flexes the neck

Front 7

Posterior scalene

Back 7

Attachment A: posterior tubercles of transverse processes of C5 & C6
Attachment B: 2nd and/or 3rd rib
Action:
if transverse process fixed:
elevates the ribs for respiration
if ribs fixed:
rotates to side opposite of contraction
laterally flexes to the contracted side
bilaterally flexes the neck

Front 8

Sternocleidomastoid

Back 8

Origin: (two heads)
manubrium of sternum
medial portion of clavicle
Insertion: mastoid process of temporal bone
Action:
rotates to side opposite of contraction
laterally flexes to the contracted side
bilaterally flexes the neck

Front 9

Platysma

Back 9

Origin: subcutaneous skin over delto-pectoral region
Insertion: invests in the skin widely over the mandible
Action:
depress mandible and lower lip
tenses the skin over the lower neck

Front 10

Occipitalis (2 bellies)

Back 10

Origin:
lateral 2/3 of superior nuchal line
external occipital protuberance
Insertion: galea aponeurosis, over the occipital bone
Action: draws back the scalp to raise the eyebrows and wrinkle the brow

Front 11

Frontalis (2 bellies)

Back 11

Origin: galea aponeurosis, anterior to the vertex
Insertion: skin above the nose and eyes
Action: draws back the scalp to raise the eyebrows and wrinkle the brow

Front 12

Orbicularis oculi

Back 12

Origin:
orbital portion: nasal process of frontal bone
palpebral portion: palpebral ligament
lacrimal portion: lacrimal crest of lacrimal bone
Insertion: circumferentially around orbit meeting in palpebral raphe
Action: powerfully closes the eye

Front 13

Orbicularis oris

Back 13

Origin:
alveolar border of maxilla
lateral to midline of mandible
Insertion:
circumferentially around mouth
blends with other muscles
Action:
closes the lips
protrudes the lips

Front 14

Zygomaticus minor

Back 14

Origin: zygomatic bone, posterior to maxillary-zygomatic suture
Insertion: skin of the upper lip
Action: elevates the upper lip

Front 15

Zygomaticus major

Back 15

Origin: anterior to zygomatic-temporal suture
Insertion: modiolus (angle of the mouth)
Action: lifts and draws back the angle(s) of the mouth (as in smiling)

Front 16

Buccinator

Back 16

Origin:
posterior alveolar process of maxilla
posterior alveolar process of mandible
along the pterygomandibular raphe
Insertion: modiolus
Action: compresses the cheek(s)

Front 17

Masseter

Back 17

Origin:
Superficial:
zygomatic process of the maxilla
inferior border of zygomatic arch
Intermediate: inner surface of zygomatic arch
Deep: posterior aspect of inferior border of zygomatic arch
Insertion:
Superficial:
angle of mandible
lateral surface of mandibular ramus
Intermediate: ramus of mandible
Deep:
superior ramus of mandible
coronoid process of mandible
Action:
closes the lower jaw (clenches the teeth)
may deviate mandible to opposite side of contraction

Front 18

Superior oblique

Back 18

Origin: body of sphenoid
Insert: upper lateral quadrant of the posterior half of the sclera (via the trochlea, as a pulley)
Action:
depress
medially rotates
abducts the eye

Front 19

Inferior oblique

Back 19

Origin: orbital surface of maxilla
Insert: lower lateral quadrant of the posterior half of the sclera (via the suspensory ligament, as a pulley)
Action:
elevates
laterally rotates
abducts the eye