Origin- Superficial Head: inferior border of the anterior 2/3 of zygomatic arch. Deep Head: inferior surface of the posterior 1/3 of the zygomatic arch and entire medial side of the zygomatic arch.

Insertion- lateral side of the angle of the mandible

Action- elevates mandible, closing the mouth

Origin- wide origin over entire temporal fossa and fascia covering the muscle. Anterior fibers run almost vertically; posterior fibers run more horizontally over the ear.

Insertion- coronoid process of mandible

Action- Entire muscle: coronoid process is pulled up-elevates mandible. Only posterior fibers- retrudes mandible

Origin- Larger (deep) Major: medial side of lateral pterygoid plate and pterygoid fossa and a tiny area of the patine bone at the lower end of medial and lateral pterygoid plates. Smaller (superficial): maxillary tuberosity behind third molar

Insertion: medial side of the angle of the mandible

Action: elevate mandible

Origin- Smaller superior head: infratemporal crest of greater wing of sphenoid. Larger inferior head: lateral side of the later pterygoid plate

Insertion- some fibers of superior head penetrate capsule of TMJ and insert into anterior border of the disc of TMJ. Rest of fibers of superior head and all fibers of inferior head insert into neck of condyle

Action- inferior head pulls condyle forward, protrudes and depresses mandible *if one side contracts lateral excursion occurs* Superior head: biting, guides posteriro movement of disc/condyle as it goes back to a centric position

Origin- digastric notch medial t mastoid process behind the ear. Fibers run forward and down to intermediate tendon.

Insertion- forward again to insert digastric fossa on inferior surface of the mandible at the midline

Action- retract mandible, pulls backward with contraction. If jaw clenched, contraction elevates hyoid, lifts larynx. Also aids in pulling mandible downward.

Origin- mylohyoid line on the medial surface of the body of the mandible

Insertion- into the hyoid bone

Action- depress mandible and elevate hyoid

Origin- inferior genial tubercle on lingual surface of mandible at midline

Insertion- runs deep to mylohyoid- down and back to insert into hyoid bone

Action- depress mandible, elevate hyoid

Origin- styloid process of base of skull runs downward and forward

Insertion- posterior (juction of body and greater cornu) part of hyoid bone

Action- pulls hyoid bone posteriorly and superiorly

Origin- Superior belly: hyoid bone; Inferior belly: upper border scapula

Insertion- intermediate tendon beneath sternocleidomastoid muscle

Action- pulls hyoid downward

Origin- upper border of sternum (runs upward)

Insertion- hyoid bone

Action- pulls hyoid downward

Origin- upper part of sternum

Insertion- into an oblique line on the side of the thyroid cartilage of the larynx

Action- pulls larynx downward

Origin- an oblique line on lateral side of thyroid cartilage

Insertion- hyoid bone

Action- lifts thyroid cartilage and raises larynx or helps depress hyoid bone

-Hyoid bone pulled upward slightly by contraction of suprahyoid muscles

-Thyrohyoid contracts elevating thyroid cartilage of larynx (along with)

-Muscles attached to epiglottis contract

-Backward movement of tongue moves epiglottis over opening of larynx, allowing swallowing

Origin- upper border of sternum and medial 1/3 of clavicle

Insertion- mastoid process of temporal bone

Action- tilting and rotating head

Origin- External occiptal protuberance on occipital bones and superior nuchal lines. Spinous process of cervical and thoracic vertebrae.

Insertion- into spince of scapula, acromion process of scapula and lateral 1/3 of clavicle

Action- adduct and elevate scapula and slightly rotate it