Muscles of the Head and Neck

Occipitofrontalis Muscle - combination of frontalis and occipitalis muscles connected by an aponeurosis (a flat, broad tendon)

Frontal belly - lies over frontal bone (raises eyebrows and wrinkles forehead)

Occipital belly - lies over occipital bone (pulls scalp posteriorly)

Orbicularis Oculi - circular muscles that encircles the eye (closes eye)

Zygomaticus major - between zygomatic bone and corner of mouth; inferior to zygomatic minor (raises corners of mouth; smiling)

Zygomaticus minor - between zygomatic bone and corner of mouth (raises upper lips, exposing upper teeth)

Orbicularis oris - circular muscle that encircles the mouth (closes and purses lips)

Platysma - wide, flat muscle that covers lower mandible and entire anterior neck, and ends on chest (tenses neck skin; depresses mandible - pouting)

Temporalis - lies over temporal bone (elevates and retracts mandible)

Masseter - anterior to ear between zygomatic arch and posterior portion of mandible (elevates and retracts mandible)

Buccinator - deep to masseter, fibers run transversely and form fleshy part of the cheek (presses cheeks inward to whistle, blow, and suck - helps hold food between teeth while chewing)

Lateral pterygoid - deep to masseter and superior to medial pterygoid, transverse muscle fibers between pterygoid process of sphenoid and mandible (protracts mandible, depresses mandible (opening mouth), and moves it sideways)

Medial pterygoid - deep to masseter and inferior to lateral pterygoid, vertical muscle fibers between pterygoid processes of sphenoid and mandible (elevates and protrudes mandible and moves it sideways)

Sternocleidomastoid - strap-like muscle on anterior and lateral neck, fibers run diagonally across the neck from the sternum and clavicle to the mastoid process (bilateral contraction flexes head (prayer muscle), unilateral contraction laterally flexes head and rotates head to opposite side as in saying no)

Scalenes - three muscles - anterior, middle, and posterior scalenes - located in lateral neck deep to sternocleidomastoid (Bilateral contraction flexes head and elevates 1st and 2nd ribs during deep inspiration, unilateral contraction laterally flexes head and rotates head to opposite side as in saying no)

Splenius capitis - posterior neck deep to trapezius (extends head when both muscles contract, laterally flexes and rotates head to same side as contracting muscles when only one muscle contracts)

Trapezius - superficial muscle of the upper back and posterior neck (extends head and elevates scapula)

Levator scapulae - posterior to sternocleidomastoid; runs diagonally from posterior head to scapula. (elevates scapula and rotates it downward; stablizes scapula)

Digastric (anterior belly) - strap-like muscle under chin that is parallel to midline of chin and extends from posterior belly (elevates hyoid bone and depresses mandible as in opening mouth)

Digastric (posterior belly) - runs along posterior border of chin (elevates hyoid bone and moves it posteriorly)

Stylohyoid - chin muscle, medial to posterior belly of digastric (elevates hyoid bone and moves it posteriorly)

Mylohyoid - deep muscle of chin extending from right side of mandible to left side (elevates hyoid bone and floor of oral cavity and depresses mandible)

Omohyoid - lateral to sternohyoid (depresses hyoid bone)

Sternohyoid - runs along midline of anterior neck