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