Lecture 24: Temporal and Infratemporal fossa Flashcards
mastication
mechanical breakdown of food within the oral cavityw
what are the two types of mastication
slicing/puncture and grinding
what bones make up the temporomandibular joint
condyle of the mandible and the mandibular fossa of the temporal bone
what divides the TMJ into dorsal and ventral halves
thin cartilaginous disc
what does the dorsal half of TMJ allow
permits mandibular condyle to slide rostrally or caudally back into place
what does ventral half of TMJ allow
permits a hinge-like opening and closing
what ligament in TMJ prevents lateral displacement of condyle and when the mouth is open, excessive rostral displacement
lateral ligament
what prevents posterior displacement of TMJ
retroarticular prodcess
what prevents ventral displacement of TMJ
joint capsule and surrounding muscles
what cranial nerve innervates all muscles of mastication
CN V3- mandibular branch of trigeminal
what are the four major muscles of mastication
temporalis, lateral pterygoid, medial pterygoid and masseter
temporalis OINA
O: temporalis fossa (some fibers from nuchal crest)
I: coronoid process on mandible
N: CN V3- mandibular
A: bilateral- jaw closing
Masseter OINA
O: zygomatic arch
I: angular process and masseteric fossa of mandible
N: CN V3- mandibular
A: bilateral- jaw closing, unilateral- superficial fibers protract and deep fibers retract or move laterally
medial pterygoid OINA
O: pyterygopalatine fossa
I: medial aspect of mandibular ramus and angular process
N: CN V3- mandibular
A: bilateral- jaw closing, unilateral- protraction
lateral pterygoid OINA
O: pterygoidpalatine fossa
I: capsule of TMJ and the articular disk
N: CN V3- mandibular
A: control the position of the articular disk during jaw movement
what muscles are the predominant muscles for mastication in carnivores and omnivores
temporalis muscle
what is the difference between the zygomatic arch and coronoid process in carnivores and omnivores vs herbivores
carnivores and omnivores- zygomatic arch flares laterally to accommodate for larger coronoid process and muscle mass
herbivores: zygomatic arch is usually less prominent and coronoid process is greatly reduced
what are the predominant muscles for mastication in herbivores
masseter and medial pterygoid
how is the TMJ restricted in species where slicing and crushing are primary mastication functions
unilateral protraction and retraction are restricted by a more hinge-like TMJ
how is the TMJ restricted in a species where grinding is more important
unilateral protraction and retraction is very important therefore TMJ is less restricted rostrally
mylohyoid OINA
O: along the length of the medial aspect of the mandibular body
I: midline raphe with fibers from opposite muscle and basihyoid
N: myloyhoid nerve from CN V3
A: raises the floor of oral cavity to support the tongue and draws basihyoid rostrally
diagastric muscle OINA
O: paracondylar process
I: medial and ventral aspect of the mandible
N: rostral-mylohyoid CN V3 and facial CN VII
A: active depression of mandible
occipitomandularis
accessory belly of caudal diagastric found in horses
what nerve provides motor innervation to muscles of mastication and sensory innervation to ear, cheek, jawline, lower lip, tongue, and mandibular teeth
mandibular nerve
where does buccal nerve run
runs rostrally passing dorsal to lateral ptyergoid
what nerve innervates the skin of the cheek and underlying oral mucosa
buccal nerve
where does the auriculotemporal nerve run
travels laterally passing caudal to retroarticular process to emerge on the superficial surface of face between masseter and auricular cartilage
what nerve innervates parts of the external ear, most of skin overlying temporalis, masseter, and zygomatic arch
auriculotemporal nerve
what is the pathway for the inferior alveolar nerve
travels ventrally passing between two pterygoids to enter mandibular foramen
what nerve innervates mandibular teeth
inferior alveolar nerve
what nerve carries sensory information from skin of the chin
mental nerve
what nerve innervates skin ventral to mandibular body and continues rostrally to innervate mylohyoid and rostral diagastric muscles
mylohyoid nerve
what is the pathway of lingual nerve
runs parallel and rostral to inferior alveolar nerve passing medially to mandible to enter the caudal aspect of the oral cavity
what nerve carries sensory innervation to the rostral two thirds of the tongue and lingual mucosa
lingual nerve
what nerve carries special sensory (taste) and preganglionic PNS fivers from facial nerve
lingual nerve
what artery is the main blood supply to deep and extra cranial regions of the head
maxillary artery
what are the 3 parts of maxillary artery
mandibular, pterygoid, pterygopalatine
what supplies blood to temporalis, masseter and part of pterygoid mass, TMJ and ear
mandibular portion of maxillary artery
what are two branches of mandibular artery
inferior alveolar- runs with nerve
middle meningeal artery
where does the middle meningeal artery enter
oval foramen
what is the largest of the blood vessels to the dura and calvaria
middle meningeal artery
what supplies blood to part of temporalis, pterygoid, orbit, palate and nasal cavity
pterygopalatine portion of maxillary artery
what artery branches off pterygopalatine artery
buccal artery
what vein provides the primary connection between venous drainage of deep parts of the head and superficial venous system
maxillary vein
how is the maxillary vein formed
union of smaller veins from pterygoid plexus caudal to alar canal
what two veins join together to form external jugular vein
maxillary and linguofacial
