Nasal and Oral Cavities

what is above the nasal cavity and what separates them?

anterior cranial fossa, perforated cribriform plate of the ethmoid bone

what is lateral to the upper half of the lateral wall of the nasal cavity?

ethmoid air sinus

what is lateral to the ethmoid sinus?

the medial wall of the orbit

what is lateral to the lower half of the lateral nasal walls?

maxillary air sinus

what is below the floor of the nasal cavity, and what separates them?

oral cavity, hard palate

what is the nasal cavity continuous with posteriorly?

the nasopharynx

what makes up the roof of the nasal cavity?

nasal cartilages, nasal bone, nasal spine of the frontal bone, cribriform plate of the ethmoid bone, anterior and inferior aspects of the body of the sphenoid bone

what makes up the floor of the nasal cavity?

palatine process of maxilla, horizontal plates of palatine bone

what makes up the medial wall of the nasal cavity?

nasal septum- made of septal cartilage, perpendicular (vertical) plate of ethmoid bone, vomer

what makes up the lateral wall of the nasal cavity?

maxilla, ethmoid bone (superior and middle conchae), inferior concha, palatine bone

what 4 passages do the nasal conchae divide the nasal cavity into?

sphenoethmoidal recess, superior meatus, middle meatus, inferior meatus

how do secretions from the orbit and paranasal sinuses drain into the nasal cavity?

through openings in the lateral wall

how do tears produced by the lacrimal gland get removed from the orbit?

the nasolacrimal apparatus- the nasolacrimal duct drains to the inferior meatus of the nasal cavity

hiatus semilunaris

curved depression found in the middle meatus

what drains via the hiatus semilunaris?

anterior ethmoidal sinus, frontal sinuses, maxillary sinuses

bulla ethmoidalis

swelling on the superior border of the hiatus semilunaris

paranasal sinuses

air filled extensions of the respiratory part of the nasal cavity into the frontal, ethmoid, sphenoid, and maxillary bones

frontal sinuses

between the outer and inner tables of the frontal bone, posterior to the superciliary arches and the root of the nose

what does each of the frontal sinuses drain through, and where does that lead?

frontonasal duct, opens into the semilunar hiatus of the middle nasal meatus

ethmoidal cells (sinuses)

small cavities in the ethmoid bone between the nasal cavity and the orbit

sphenoidal sinuses

located in the body of the sphenoid, are separated by a bony septum

what important structures are separated from the sphenoidal sinuses only by thin plates of bone?

optic nerves and optic chiasm, pituitary gland, internal carotid arteries, cavernous sinuses

where do the sphenoidal sinuses drain?

the sphenoethmoidal recess

maxillary sinuses

largest of the paranasal sinuses, occupy the bodies of the maxillae and communicate with the middle nasal meatus

the medial wall of the maxillary sinus forms the…

inferior part of the lateral wall of the nasal cavity

the roof of the maxillary sinus is formed by the…

floor of the orbit

the floor of the maxillary sinus is formed by the…

alveolar part of the maxilla of the oral cavity

maxillary ostium

the openings in the maxillary sinus that allow for drainage

each maxillary sinus drains by the maxillary ostium into the ____ nasal meatus of the nasal cavity by way of the _______

middle, semilunar hiatus

vestibule

space between the teeth and mucosal lining of the lips and cheeks (labial and buccal mucosa)

oral cavity proper

space between upper and lower dental arches

lips

controlled by muscles of facial expression which are innervated by CN VII

philtrum

external midline feature of the lips

buccinator

thin, flat, rectangular muscle that arises from the pterygomandibular raphe and attaches laterally to the alveolar processes of the maxillae and mandible, opposite the molar teeth

it occupies a deeper plane than the other facial muscles and is more closely related to the buccal mucosa than the skin of the face

where does the parotid (stensen’s) duct open?

in the oral vestibule opposite the crown of the second molar

palate

forms the roof of the oral cavity proper and floor of nasal cavity, has 2 distinct parts: hard and soft

hard palate

forms rigid surface for food during chewing, formed from palatine process of maxilla and horizontal plate of palatine bone (includes posterior nasal spine)

what foramen are associated with the hard palate?

incisive fossa, greater palatine foramen, lesser palatine foramen

incisive fossa

behind the central incisors, nasopalatine nerve and sphenopalatine vessels pass through

greater palatine foramen

on the lateral posterior aspect of the palate, greater palatine nerves and vessels pass through

lesser palatine foramen

posterior to the greater palatine foramen, lesser palatine nerve and vessels pass through

soft palate

rises as a reflex to close off nasopharynx during swallowing, sides are attached to pharyngeal walls

what muscles make up to soft palate?

levator veli palatini, tensor veli palatini, palatoglossus, palatopharyngeus, musculus uvulae

what is the function of the levator veli palatini?

elevate the soft palate

what is the function of the tensor veli palatini?

flatten and tense the soft palate

what is the function of the palatoglossus muscle?

elevates the posterior 1/3 of the tongue

what is the function of the palatopharyngeus muscle?

elevate the pharynx and larynx

what is the function of the musculus uvulae?

retract and elevate the uvula

tonsils

aggregates of lymphoid tissue, palatine, lingual, and pharyngeal

palatine tonsils

bilateral, located at boundary of oral cavity and pharynx

lingual tonsils

located on dorsal surface of posterior tongue

pharyngeal tonsils

single mass, located in roof of nasopharynx (adenoids)

sulcus terminalis

location where the anterior 2/3 and posterior 1/3 of tongue meet

tongue

has ventral and dorsal surfaces, composed of intrinsic and extrinsic muscles

lingual frenulum

a midline fold of mucous membrane running from the lingual gingiva behind the mandibular central incisors posteriorly to the undersurface of the tongue

sublingual papilla (caruncle)

located on either side of the frenulum and is the opening of the duct of the submandibular gland (wharton’s duct)

what is the purpose of the extrinsic muscles of the tongue?

move the tongue around (up/down, side to side)

what is the bony attachment of the genioglossus?

superior genial (mental) spine

what is the bony attachment of the hyoglossus?

hyoid bone

what is the bony attachment of the styloglossus?

styloid process

what is the action of the genioglossus?

depresses and protrudes the tongue

what is the innervation of the genioglossus?

hypoglossal nerve

what is the action of the hyoglossus?

depresses and retracts the tongue

what innervates the hyoglossus?

hypoglossal nerve

what is the action of the styloglossus?

retracts tongue

what innervates the styloglossus?

hypoglossal nerve

what is the action of the palatoglossus?

elevates posterior part of tongue

what innervates the palatoglossus?

pharyngeal plexus via CN X

what is the function of the intrinsic muscles of the tongue?

change the shape of the tongue

what nerve are all the intrinsic muscles of the tongue innervated by?

CN XII

what is the main artery to the tongue?

lingual artery, branch of the external carotid artery

what does the dorsal lingual artery supply?

the root of the tongue

what does the deep lingual artery supply?

the body of the tongue

what does the sublingual branch of the lingual artery supply?

the floor of the mouth

where do the veins of the tongue and floor of the oral cavity travel?

with the arteries of the same name

where do the deep lingual veins run?

posteriorly under the mucous membrane of the underside of the tongue at the side of the lingual frenulum

where do all branches of venous drainage in the tongue and floor of the oral cavity drain to?

the lingual vein to the internal jugular vein

where do the lymphatics of the tip of the tongue drain to?

submental group

where do the lymphatics of the side of the tongue drain to?

submandibular group

where do the lymphatics of the central part of the tongue drain to?

jugulo-omohyoid group

where do the lymphatics of the posterior 1/3 of the tongue drain to?

jugulo-digastric group and jugulo-omohyoid group

mylohyoid muscles

a muscular diaphragm that fills the U shaped gap between the sides and body of the mandible, paired muscles

what are the attachments of the mylohyoid muscle?

mylohyoid line of the mandible to the median raphe and hyoid bone

what innervates the mylohyoid?

nerve to mylohyoid from inferior alveolar nerve

geniohyoid

two cord-like muscles above the diaphragm, run from the mandible to the hyoid

what are the attachments of the geniohyoid?

inferior mental spines of the mandible to the body of the hyoid bone

what nerve innervates the geniohyoid?

C1

what glands are on the floor of the mouth?

submandibular duct and sublingual gland and ducts

what does the lingual nerve provide?

sensory from anterior 2/3 of the tongue

what does the hypoglossal nerve provide?

motor to intrinsic and extrinsic muscles of the tongue (-1 muscle)

what does Wharton’s duct connect?

submandibular gland to the oral cavity (opens lateral to lingual frenulum)

what does the sublingual duct connect?

the sublingual gland to the oral cavity or submandibular duct

where does the lingual nerve begin?

it is a branch of the posterior division of the mandibular nerve (CN V3) within the infratemporal fossa

what is the pathway the lingual nerve takes from the infratemporal fossa until it is joined by the chorda tympani?

curves downward and forward to emerge between the medial and lateral pterygoid muscles, where it is joined by the chorda tympani

what is the pathway of the lingual nerve after it is joined by the chorda tympani?

it continues anteriorly and downward to enter the floor of the mouth just medial to the root of the mandibular 3rd molar

what is the pathway of the hypoglossal nerve?

it leaves the skull through the hypoglossal canal and descends almost vertically in the neck to a level just below the mandible, it sharply angles forward and crosses the external carotid artery, continues forward and crosses the lingual artery to reach the hyoglossus muscle

it continues to travel on the external surface of the hyoglossus muscles and deep to the mylohyoid muscle to reach the tongue

what structure is labeled A?

chorda tympani

what structure is labeled B?

lingual nerve

what structure is labeled C?

submandibular duct

what structure is labeled A?

geniohyoid