Head and Neck Muscles

Orbicularis Oculi

Encircles the eye
Closes the eye - winking

Levator Labii Superioris

Between orbicularis oris and inferior eye margin

Skin and muscle of upper lip

Raises and furrows upper lip; opens lips

Zygomaticus Minor and Major

Extends diagonally from corner of mouth to cheekbone

Skin and muscle at corner of mouth

Raises lateral corners of mouth upward (SMILING MUSCLE)

Buccinator

Principle muscle of cheek

Encircles mouth

Draws corner of mouth laterally (WHISTLING); holds food between teeth while chewing

Orbicularis Oris

Multilayered muscle of lips with fibers encircling lips

Encircles mouth

Closes lips; purses and protrudes lips (KISSING AND WHISTLING)

Depressor Labii Inferioris

Small muscle running from lower lip to mandible

Skin and muscle of lower lip

Draws lower lip inferiorly

Triangularis

Small muscle lateral to depressor labii inferioris

Skin and muscle at angle of mouth below insertion of zygomaticus

Zygomaticus antagonist; draws corners of mouth downward and laterally

Platysma

Unpaired, thin, sheetlike superficial neck muscle, plays role in facial expression

Lower margin of mandible, skin, and muscle at corner of mouth

Tenses skin of neck; depresses mandible; pulls lower lip back and down

Galea Aponeurotica

Tendonous structure covering the top of the skull, connecting frontalis and occipitalis muscles

Serves as a sheet for muscle attachment and contributes to facial expressions.

Frontalis and occipitalis

Bipartite muscle consisting of frontal and occipital bellies, covers dome of skull

Frontal belly- skin of eyebrows and root of nose, raises eyebrows

Occipital belly- back of head, pulls scalp posteriorly

Temporalis

Fan shaped muscle lying over parts of frontal, parietal, and temporal bones

Coronoid process of mandible

Closes jaw; elevates and retracts mandible

Masseter

Covers lateral aspect of mandibular ramus; can be palpated on forcible closure of jaws

Angle and ramus of mandible

Prime mover of jaw closure; elevates mandible

Sternocleidomastoid

Two headed muscle located deep to platysma on anterolateral surface of neck

Mastoid process of temporal bone and superior nuchal line of occipital bone

Simultaneous contraction of both muscles of pair causes flexion of neck, acting independently, rotate head toward shoulder on opposite side

Digastric

Consists of two bellies united by an intermediate tendon; forms a v-shape under chin

By a connective tissue loop to hyoid bone

Acting together, elevate hyoid bone; open mouth and depress mandible

Thyrohyoid

Appears as a superior continuation of sternothyroid muscle
Hyoid bone
Depresses hyoid bone or elevates larynx

Sternothyroid

Lateral and deep to sternohyoid

Thyroid cartilage of larynx

Depresses hyoid bone or elevates larynx

Mylohyoid

Just deep to digastric; forms floor of mouth

hyoid bone and median raphe

Elevated hyoid bone and base of tongue during swallowing

Omohyoid

Straplike with two bellies; lateral to sternohyoid

Hyoid bone

Depresses hyoid bone or elevates larynx

Sternohyoid

Runs most medially along the neck; straplike

Lower margin of hyoid bone

Depresses hyoid bone or elevates larynx