Chapter 7: Muscles of Mastication

Geniohyoid muscle

-Floor of the mouth - Depresses the mandible - Innervated by C1 -originates in the mental spine of the mandible -inserts at hyoid bone

mylohyoid muscle

-Floor of the mouth - Depresses the mandible - Innervated by the mandibular nerve

elevate, protrusion

In masseter muscle, the superficial fibers _______ and provide limited ______. a) retrude, protrusion b) elevate, protrusion c) elevate, retrusion

diagonal

In masseter muscle, the superficial head has ______ fibers while the deep head has VERTICAL fibers.

a) anterior belly of digastric b) mylohyoid

2 muscles that are innervated by mandibular nerve

auriculotemporal nerve of V3

Nerve that supplies sensory fibers to the TMJ.

temporalis muscle

#1 -Covered by temporalis fascia - Originates from the bones of the temporal fossa and the temporalis fascia - Inserts on the coronoid process and the border of the ramus of the mandible -elevates and retrudes the jaw

zygomatic arch

#2

superficial head of masseter muscle

#3

deep head of masseter muscle

#4

tendon of temporalis muscle

#5

coronoid process

#6

superior head of lateral pterygoid plate

#7

inferior head of lateral pterygoid plate

#8

medial pterygoid muscle

#9

Masseter muscle

- Superficial head • Diagonal fibers - Deep head • Vertical fibers - Originates from the zygomatic arch - Inserts on the mandible

buccinator muscle

-Muscle of facial expression - Keeps food in the oral cavity while chewing -origin: pterygomandibular raphe -insertion: corner of the mouth -action: tightens the cheek wall while chewing -innervated by facial nerve

digastric muscle

-Muscles of the neck - Assists in the depression of the jaw -depress the mandible -innervated by mandibular nerve (anterior) and facial nerve (posterior)

temporalis fossa

-covers the temporalis muscle

Stenson's duct

-excretory duct of parotid gland

mylohyoid

-muscle of the floor of the mouth that forms a sling

retrodiscal pad

-the area behind the articular disc -contains blood vessels and sensory nerves of mandibular nerve that supply that joint

medial pterygoid muscle; elevates

Superficial head • Originates from maxillary tuberosity - Deep head • Originates from the medial surface of the lateral pterygoid plate - Inserts on ramus of the mandible - Action: ____________, retrudes and protrudes the jaw

lateral pterygoid muscle; elevates

Superior head • Originates from infratemporal crest of sphenoid bone - Inferior head • Originates on the lateral surface of the lateral pterygoid plate - Inserts on capsule and disc of the TMJ - Action: ***__________ and protrudes the jaw

a) buccinator muscle b) posterior belly of digastric muscle

What are the 2 secondary muscles that innervate by facial nerve?

1) temporalis 2) masseter 3) lateral pterygoid 4) medial pterygoid

What are the 4 PRIMARY muscles of mastication?

1) buccinator 2) digastric 3) mylohyoid 4) geniohyoid

What are the 4 secondary muscles of mastication?

temporal fossa

What fossa is this that is bound by frontal, parietal, sphenoid, and temporal bones?

infratemporal fossa

What fossa is this that is bounded by MAXILLARY BONE, MEDIAL SURFACE OF THE MANDIBLE, STYLOID PROCESS, AND LATERAL PTERYGOID PLATE?

temporalis muscle

What is number 1?

mandibular nerve

What is the one and only innervation of the 4 primary muscles of mastication?

temporal fossa

a space that's located superior to the zygomatic arch and contains the temporalis muscle

maxillary tuberosity

letter E