muscles of mastication Flashcards
Which muscle originates at the zygomatic arch?
Massenter
Where does the massenter muscle insert?
Massenteric Fossa
What function does the Massenter muscle do?
helps with the jaw closing
Where does the Temporalis muscle originate?
Frontal, parietal, and temporal
What inserts at the coronoid process?
Temporalis
What function does the Temporalis muscle do?
Helps with the jaw closing
Where does the Pterygoids originate?
At the Pterygoid bones
What inserts at the medial side of the mandible?
Ptyergoids - medial and lateral
Which muscles close the jaw?
Massenter, Temporalis, and pterygoids
What originates at the Occipital Bone? (green)
Digatricus - the Jugular process (between occipital condyle & temporal bolus)
Where does the Digatricus insert?
The ventral aspect of the mandible
What is the TMJ?
The Temporomandibular Joint
Describe the TMJ in carnivores
confined, bony process, locked - limited movement Temporalis muscle important
Hinge-like, flatter, articular surface allowing for lateral movements
TMJ of herbivores
Which muscles are associated with lip movements?
Orbicularis oris, canius, levator nasolabialis, levator labii superioris, levator labii inferioris
Which muscles are associated with cheek movements?
Buccinator
What does the Buccinator do?
Squeezes cheeks for chewing, returns food from vestibule to oral cavity
What muscle raises the area of upper lip under nose?
Orbicularis orbitus
Which muscle is associated with snarling in canids?
Canius
What does the levator nasolabialis innervate?
Lifts nose and upper lip
Which muscle lifts the upper lip?
Levator labii superioris
What does the Depressor labii inferious innervate?
depresses lower lip (not in cats/dogs)
What nerve innervates all the muscles discussed?
Cranial nerve VII = facial nerve
What muscle is this?
The buccinator
