Infratemporal Fossa And Nasal Cavity Flashcards
Infratemporal fossa boundaries
Lat. med. surface of ramus of mandible
. Ant: body of maxilla
. Med: lat. pterygoid plate of sphenoid, sup. Pharyngeal constrictor, and tensor and levator veli palatine mm.
. Post: tympanic plate, mastoid and styloid processes
. Roof: greater wing of sphenoid and squamous portion of the temporal bone w/ foramen ovale and foramen spinosum
Foramen ovale
. Transmits CN V3 from middle cranial fossa to infratemporal fossa
Foramen spinosum
. Transmits middle meningeal a. From infratemporal fossa into middle cranial fossa
Contents of infratemporal fossa
. Med. and lat. pterygoid mm.
. Maxillary a.
. Pterygoid plexus of vv.
. Mandibular division of trigeminal n. And its branches
Maxillary aa.
. 1 of 2 terminal branches of external carotid a.
. Arises w/in parotid gland and enters infratemporal fossa by passing deep to ramus of mandible
. Exits fossa via pterygomaxillary fissure where it terminates by splitting into sphenopalatine and descending palatine aa.
Branches of maxillary a.
. Deep auricular and ant. Tympanic aa. To ear
. Middle meningeal a.
. Inf. Alveolar a.
. Accessory meningeal a.
. Muscular branches to temporalis (deep temporal a.), pterygoid, and buccinator mm. (Buccal a.)
. Post. Sup. Alveolar a.
. Infraorbital a.
Middle meningeal a. Pathway
. Enters skull via foramen spinosum
. Supplies dura and adjacent bone
Inferior alveolar a.
. Enters mandible via mandibular foramen
. Supplies lower teeth and mandible
. Terminates as mental a.
Accessory meningeal a. Pathway
. Inconsistent
. Enters skull via foramen ovale
Post. Sup. Alveolar artsy pathway
. Enters body of the maxilla to supply upper teeth post.
Infraorbital a. Pathway
. Courses sup. Near maxilla to enter the inf. Orbital fissure
. Courses through infraorbital groove, canal, and foramen
. Gives off ant. Sup. And middle alveolar aa. Which supply upper teeth
Pterygoid plexus of veins
. Drains area supplied by maxillary a.
. Connect w/ veins in interior of skull
. Valveless
. Possible routes for transmission
Mandibular division of CN V3
Largest division of CN V w/ sensory and motor fibers
. Only division of CN V that has voluntary motor fibers
. Enters infratemporal fossa via foramen ovale
. Otic ganglion (parasympathetic) is attached to it w/in foramen
.
Otic ganglion
. Preganglionic parasympathetic fibers conveyed in lesser petrosal n. Synapse
. Postganglionic fibers coveyed by auriculotemporal n. (Branch of CN V3) to parotid gland
Auriculotemporal n.
. Branch of V3 that Arises from 2 roots that encircle meningeal a. As it enters foramen spinosum
. Conveys postganglionic parasympathetic fibers from otic ganglion to parotid gland
Inf. Alveolar n.
. Branch of V3
. Gives off mylohyoid n. Just prior to mandibular foramen entry
. Courses through mandible supplying sensory innervation to lower teeth, mandible, and lower lip
. Gives off mental n. Providing sensory to chin
Mylohyoid n.
, branch of inf. Alveolar n.
. Supplies somatic motor fibers to mylohyoid m. And ant. Belly of digastric m.
Lingual n.
. Branch of V3
. Courses deep to mandible to reach tongue
. Joined by chorda tympani (branch of CN VII)
. Conveys general sensory innervation from oral cavity, special sensory to ant. 2/3 tongue, and preganglionic parasympathetic fibers to submandibular and sublingual and mucosal glands of mouth (via chorda tympani)
Chorda tympani
. Converts special sensory fibers and preganglionic parasympathetic fibers that synapse in sunbmandibular ganglion
Buccal n.
. Branch of V3
. Descends on superficial surface of buccinator
. Sensory to cheek
Muscular branches of V3
. Deep temporal nn. To temporalis . Masseteric nn. . Nn. To lat. and med. pterygoid mm. . N. To tensor tympani . N. To tensor veli palatini
TMJ
. Synovial joint btw mandibular condyle and temporal bone
. Articular surfaces: mandibular fossa and articular tubercle/process/eminence of temporal bone
. Has intra-articular disc w. Thick post. Band, thin central part, and thick ant. Band
. Disc divides joint into sup. And inf. Compartments
. Sup compartment: gliding motion from head of mandible moving from mandibular fossa to articular part of temporal bone due to action from lat. pterygoid m.
. Inf. Compartment: hinge movement of condylar head
TMJ ligaments
. Lat. temporomandibular ligament: runs posteroinf. From zygomatic tubercle to mandibular neck, thickening of fibrous capsule
. Capsule w/ extrinsic ligaments: sphenomandibular and stylomandibular ligaments
Movements of mandible
. Depression: open mouth, can’t be fully done unless condyle glides ant. From fossa tp articular tubercle
. Elevation: closing mouth
. Protraction/Retraction: ant./post. Movement, occurs in sup. Compartment
. Lat. deviation to left or right, going to left the contralateral condyle glides ant. While ipsilateral condyle pivots
. Pivoting of condyle about a vertical axis involves sup. Compartment
TMJ dislocation
. Occurs when opening mouth excessively
. Condyle slips ant. To articular tubercle
. When mm. Elevate the mandible, the condyle jams upward and can’t return to mouth remains open
Nasal cavity functions c
airway, olfaction, filtration of particulate matter in inspired air, humidification of air, warming and slowing of air, secretions from paranasal air sinuses and nasolacrimal ducts
External nose features
. Attached to face at it’s root
. Inf. Tip of nose: apex
. Dorsum extends from root to apex
. Inf. Surface has openings (ant. External nares) separated by nasal septum, watch bare bounded by ala
Bridge of nose
. Sup. Bony part of nose
. Nasal bones
. Frontal processes of maxillae
. Nasal part of frontal bone
Cartilaginous parts of nose
. 5 main hyaline cartilage
. Lat. (2 of them(
. Alar (2 of them)
. Septal
Nasal septum
. Partly bony and partly cartilaginous
. Divides nose into 2 narrow nasal cavities
. Perpendicular plate of ethmoid bone
. Vomer
. Septal cartilage
. Small contributions from nasal crests of palatine and maxillae bone
Nasal cavity qualities
. Open to exterior through ant. nares and open to nasopharynx post. Through choanae (post./internal nares)
. Vestibule: dialed portion of nasal cavity immediately sup. To ant. Nares lined w/ vibrissae (coarse hairs) that prevent material from getting in
. Has olfactory (sup. 1/3) and respiratory regions (inf. 2/3)
Boundaries of nasal cavity
. Med. wall: smooth nasal septum, vomer, perpendicular plate of ethmoid, sepal cartilage
. Floor: palatine process of maxilla and horizontal plate of palatine bone covered w/ mucous membrane
. Roof: narrow, frontonasal, ethmoidal, and sphenoidal parts
. Lat. wall: uneven, 3 conchae/turbinates covered w/ mucous membranes sup. One is round and small part of ethmoid, middle is larger and part of ethmoid, inf. Is largest and is a separate bone
Nasal meatus
. Space inf. And lat. to each concha
. Receive Ostia (openings) of paranasal sinuses and nasolacrimal duct
Sup. Nasal meatus
. Narrow space btw sup. And middle conchae
. Contains Ostia of post. Ethmoidal sinuses
Middle nasal meatus
. Larger and wider than sup. Meatus
. Btw middle and inf. Conchae
. Contains rounded elevation (ethmoidal bulla) formed by middle ethmoidal sinuses that open onto it
. Inf. To that is a crescent-shaped groove (semilunar hiatus) w/ several Ostia
Semilunar hiatus
. Ant. Ethmoidal sinuses open ant. Into this groove
. Frontal sinus opens ant. Into it
. Maxillary sinus opens post. Into this
Inf. Nasal meatus
.space inf. And lat. To inf. Concha
, nasolacrimal duct opens into it
Sphenoethmoidal recess
. Small space post. And sup. To sup. Concha
. Sphenoidal sinus opens into this meatus
Paranasal sinuses
. Air-filled extensions of respiratory portion of nasal cavity
. Vary in size and shape in people
. Lined w/ mucous membranes continuous w/ lining of nasal cavities
. Drain directly or indirectly into nasal cavities
. Develop as outgrowths from nasal cavities after birth
. Enlarge in childhood
. Lighten weight of skull
. Frontal, ethmoidal, sphenoidal, and maxillary sinuses
Frontal sinus
. Btw inner and outer laminae of frontal bones
. Drains into ant. Portion of semilunar hiatus
Ethmoidal sinuses
. Small cavities in lat. mass of ethmoid bone
. 3 sets: ant. (Drain into middle meatus), middle (drinks directly into middle meatus along Ostia in ethmoidal bulla
. Post.: drains directly to sup. Meatus
Sphenoidal sinus
. Located in body of sphenoid bone
. Drains into sphenoethmoidal recess
Maxillary sinus
. Pyramidal shaped cavities that occupy entire bodies of maxillae
. Largest of paranasal sinuses
. Drain into middle meatus through semilunar hiatus
. Opening of sinuses are at sup. Aspect of the sinus
. Prone to infection due to difficulty in draining these sinuses
Sphenopalatine a.
. Branch of maxillary a.
. Enters nasal cavity through sphenopalatine foramen
. Sends branches to post. Regions of lat. nasal wall and nasal septum
. Anastomoses w/ branches of greater palatine a.
Greater palatine a.
. Branch of descending palatine a. From maxillary a.
. Courses inf. Through greater palatine canal and foramen
. Runs ant. On hard palate
. Passes sup. Through incisive foramen to supply nasal septum
Ant. And post. Ethmoidal aa.
. Branches of ophthalmic a.
. Supply anterosup. Part of lat. nasal wall and nasal septum as the ant. Lat. nasal and ant. Septal nasal branches
Facial a. Contribution to nasal cavity
.ant. Parts of nasal mucosa
Venous supply to nasal cavity
. Some drain int sphenopalatine v. And then into pterygoid plexus
. Some drain into facial, infraorbital, and ophthalmic vv.s that drain into cavernous venous dural sinus
Epistaxis
. Nasal hemorrhage
. Common due to rich vascularization of mucosa
Innervation of olfactory region of nose
. Axons of olfactory cells from CN I
. Pass through cribiform plate
Innervation of respiratory portion of nose
. CN V1: ant. Ethmoidal n. Is branch of nasociliary that enters nasal cavity through ant. Ethmoidal foramen to give branches to nasal septum and lat. nasal wall
. Ant. Continuation of ant. Ethmoidal n… is external nasal n. Giving cutaneous feeling to nose apex
. V2 branches from pterygopalatine ganglion: post. Sup. And post. Inf. (From greater palatine n.) Nasal branches supply lat. Wall, nasopalatine n. In groove in vomer to nasal septum then continues on mouth roof via incisive foramen
Pterygopalatine fossa
. Small triangular space inf. To apex of orbit
. Located tw pterygoid process of sphenoid bone post. And palatine med. and maxilla ant.
. Directly continuous lat. w/ infratemporal fossa through pterygomaxillary fissure
.
Pterygopalatine fossa openings
. pterygomaxillary fissure (opens lat. to infratemporal fossa)
. sphenopalatine foramen (opens med. to nasal cavity)
. greater palatine canal (opens inf. To roof of mouth)
. inf. Orbital fissure (opens ant. To floor of orbit))
. Pterygoid canal (opens post. To foramen lacerum)
. Foramen rotundum: opens post. To middle cranial fossa
. Pharyngeal canal: opens post. To pharynx
Contents of pterygopalatine fossa
. Portion of maxillary division of V2
. Pterygopalatine ganglion
. Terminal portion of maxillary a.
Branches of V2 w/in pterygopalatine fossa
. Zygomatic n.
. Greater and less palatine nn.
. Post. Sup. Nasal nn. (Med./lat. nasal walls)
. Nasopalatine nn. (Med./lat nasal walls)
. Pharyngeal n.
Zygomatic n.
. Exits pterygopalatine fossa via inf. Orbital fissure and splits into zygomaticofacial n. And zygomaticotemporal nn. That supply sensory innervation to the lat. cheek and temple
. Zygomaticotemporal n. Will also carry postganglionic parasympathetic fibers which arise in pterygopalatine ganglion and will go to lacrimal gland
Greater and lesser palatine nn.
. Descend to palate via same named canals and foramina
. Post. Inf. Nasal branches to lat. nasal wall off greater palatine n. Distribute to inf. Portion of lat. nasal wall
Pharyngeal n.
. Exits fossa via pharyngeal canal
. Innervates mucous membranes of the nasopharynx post. To auditory tube
Branches of V2 w/in the orbit
. Maxillary n. Gives off post. Sup. Alveolar nn. Which supply the gums and molar teeth
. Maxillary n. Enters the infraorbital canal and becomes the infraorbital n.
. Gives off middle and ant. Sup. Alveolar nn. To supply the upper teeth
. Infraorbital n. Will emerge via infraorbital foramen to supply lower eyelid, nose, and skin and mucosa of the cheek and upper lip
