Anatomy Lab: Muscles of mastication

The muscles of mastication work with the ______ to accomplish movements of the mandible

TMJ

The muscles of mastication are all attached in some manner to the mandible and include what 4 muscles?

Masseter Temporalis Medial pterygoid Lateral pterygoid

The origin and insertion of each muscle of mastication varies; however, all the muscles of mastication generally originate on the _____ and insert on the _____

cranium mandible

The ORIGIN of the ____ head of the masseter muscle is the posterior 1/3 and the entire medial surface of the zygomatic arch

deep

The medial pterygoid muscle also has two heads due to their differing depth, again similar to the masseter muscle: the ____ and ____ heads However, even with these two differing heads, this is the deepest muscle of mastication.

deep superficial

The action of the lateral ptyergoid muscle is the ONLY muscle of mastication that assists in _____ the mandible (lowering the jaw)

depressing

The associated movements of the mandible are: (5) These jaw movements involve the movement of the mandible, while the rest of the skull remains relatively stable

depression- brings down elevation- lifts up protrusion- moves forward retraction- moves backwards lateral deviation- side to side

The opening of the jaw, or depression, from the mastoid to hyoid bone is the _____ muscle that has 2 bellies. The origin is the hyoid bone and the insertion is the digastric fossa

digrastic

The action of the medial pterygoid muscle is to _____ the mandibe but it is not as strong as the massester muscle

elevate

The action of the temporalis muscle is to ____ the mandible and also maintain its physiologic rest position allowing freeway space

elevate

action of masseter muscle is to ______ the mandible

elevate

The INSERTION of the ____ head of the lateral pterygoid muscle is on the anterior surface of the neck of the mandibular condyle at the pterygoid fovea

inferior

The ____ head of the lateral pterygoid muscle ORIGINATES from the lateral pterygoid plate

inferior

The entire lateral pterygoid muscle lies within the _______ fossa deep to the temporalis muscle

infratemporal

When muscles contract, they bring the ______ to the origin

insertion

The ___ ___ muscle has two separate heads of origin: the superior and inferior heads. The two heads are separated anteriorly by a slight interval but fuse together posteriorly

lateral pterygoid

The ____ ____ muscle or external pterygoid muscle is a short, thick, almost conical muscle of mastication superior to the medial pterygoid

lateral pterygoid

All the muscles of mastication are innervated by the _____ nerve (or third division) of the fifth cranial or trigeminal nerve, with each nerve serving one side of the face

mandibular

The most obvious muscle of mastication is the ______ muscle since it is the most superficial and one of the strongest. It creates the most pressure. The muscle is a broad, thick, flat rectangular muscle (almost quadrilateral) on each side of the face, anterior to the parotid salivary gland

masseter

The masseter muscle is innervated by the _____ nerve, a branch of the mandibular nerve (or third division) of the fifth cranial or trigeminal nerve

masseteric

Deeper, yet similar its rectangular form to the more superficial masseter, is another muscle of mastication, the ____ _____ muscle or internal pterygoid muscle

medial pterygoid

The medial pterygoid muscle is innervated by the ___ ___ nerve which is a branch of the mandibular nerve CNV3

medial pterygoid

Both heads of the Medial Pterygoid muscle insert into what structure?

on the medial surface of the mandibular ramus and angle of the mandible

The main action of the lateral pterygoid muscle when both muscles are contracting is to bring the lower jaw forward thus causing _____ of the mandible If only one muscle is contracted, the lower jaw shifts to the contralateral side, causing lateral deviation of the mandible

protrusion

The masseter muscle has two heads that differ in depth: the superficial and deep heads The ORIGIN of the _____ head is in the anterior 2/3s of the zygomatic arch and the zygomatic process of the maxilla

superficial

The smaller _____ head of the medial pterygoid muscle ORIGINATES from the maxillary tuberosity and the pyramidal process of the palatine bone The pyramidal process of the palatine bone is right above the maxillary tuberosity where the vertical and horizontal plates of the palatine bone meet

superficial

The INSERTION of the _____ head of the lateral pterygoid muscle is on the anterior surface of the neck of the mandibular condyle at the pterygoid fovea of the mandible and the anterior margin of the TMJ disc and capsule

superior

The ____ head of the lateral pterygoid muscle ORIGINATES from the infratemporal crest of the greater wing of the sphenoid bone and the infratemporal surface

superior

Innervation of the temporalis muscle is by the deep ____ nerves, branches of the mandibular nerve (CNV3)

temporal

The temporalis muscle ORIGINATES from the entire ____ _____ on the temporal bone that is bound superiorly by the inferior temporal line and inferiorly by the infratempotal crest

temporal fossa

The ____ muscle INSERTS onto the medial and later coronoid process and anterior border of the ramus

temporalis

The _____ muscle is a broad, fan-shaped muscle of mastication on each side of the head that fills the temporal fossa, superior to the zygomatic arch

temporalis

The larger ____ head of the medial pterygoid muscle ORIGINATES from the pterygoid fossa on the medial surface of the lateral pterygoid plate

deep

The lateral pterygoid muscle is innervated by the ___ ____ nerve, a branch of the mandibular nerve (CNV3)

lateral pterygoid

The muscles of ______ are four pairs of muscles that are located deeper within the face than the muscles of facial expression

mastication