Muscles of the Head and Neck The Muscular System
General Muscle Terminology Origin: stationary point of attachment Insertion: movable point of attachment Action: Anatomical movement that results from the contraction of the muscle
General Info: Facial muscles Most muscles originate on the surface of the skull and insert into the dermis Create facial movements and expressions
Frontalis Action: raises eyebrow, wrinkles forehead
Occipitalis Action: tenses and retracts the scalp
Masseter Action: closes mandible Ex: closes mouth during chewing
Temporalis Action: elevates mandible Ex: clenching your jaw, crushing food
Orbicularis oculi Action: closes eye Ex: blinking, squinting
Nasalis Action: compresses nostril
Zygomaticus Action: draws corner of mouth upward Ex: smiling
Buccinator Action: compresses cheeks Ex: playing a trumpet, whistling
Orbicularis oris Action: compresses, purses lips Ex: kissing
Depressor anguli oris Action: depresses corner of mouth Ex: frowning
Anatomy - Human frontalis temporalis Orbicularis oculi zygomaticus masseter Orbicularis oris buccinator Depressor anguli platysma sternocleidomastoid
Epicranial aponeurosis frontalis occipitalis temporalis Orbicularis oculi nasalis zygomaticus masseter buccinator sternoclediomastoid Orbicularis oris platysma
General Info: Neck muscles Involved in Swallowing and chewing Moving your head and neck Supporting your head Anterior neck muscles work on the hyoid bone Suprahyoid muscles (above the hyoid) pull hyoid up Infrahyoid muscles (below the hyoid) pull hyoid down
Sternocleidomastoid Extends from the clavicles and the sternum to the mastoid region of the skull Actions: flexion of head, lateral flexion, rotation of head side to side
Platysma Action: tenses skin of neck, depresses mandible (opens mouth)
Digastric (“two bellies”) Action: elevates hyoid bone when swallowing; depresses the mandible (opening mouth)
Mylohyoid Broad/flat muscle provides muscular floor to the mouth and helps press tongue to top of mouth
Sternohyoid Connects the hyoid bone to the sternum Action: depresses hyoid bone and larynx
Sternothyroid Anchors the larynx to the sternum Action: depresses hyoid bone and larynx
Stylohyoid Connects the hyoid bone to the styloid process of the skull Action: elevates hyoid
digastric mylohyoid stylohyoid thyrohyoid omohyoid sternohyoid sternothyroid
Superficial muscles of the neck Sternomastoid Cleidomastoid Sternohyoid Mylohyoid Digastric Masseter Sternomastoid = #18 Cleidomastoid = #6 Sternohyoid = #17 Mylohyoid = #11 Digastric = #7 Masseter = #10 TOO DEEP TO DISSECT Stylohyoid Sternothyroid Thyrohyoid
Digastric Mylohyoid Masseter Sternohyoid sternomastoid cleidomastoid
Name the muscle… Frontalis
Buccinator and orbicularis oris Name the muscle… Buccinator and orbicularis oris
Name the muscle… Orbicularis oculi
Name the muscle… Platysma
Name the muscle… Orbicularis oris
Name the muscle… Depressor Anguli Oris