Nasal Cavity and Mouth

first permanent teeth to appear

- 1st to appear is first molar at 6 years of age - followed by inferior medial incisors

dental formula of deciduous teeth (milk teeth/baby teeth)

- 20 teeth - upper jaw: 2, 1, 2 (incisors, canine, molars) - lower jaw: 2, 1, 2 (incisors, canine, molars)

ethmoidal sinuses (form the ethmoidal labyrinth in the ehtmoid bone)

- 3 groups: anterior, middle, and posterior - middle cells form ethmoidal bulla - drainage: anterior and middle cells into middle meatus; posterior cells into the superior meatus - medial relation to orbit - rarely visible on x-ray until age 2 - innervated by: anterior/posterior ethmoidal nerves (branch of V1)

permanent teeth

- 32 teeth - upper and lower jaws: 2, 1, 2, 3 (incisors, canine, premolars, molars) - teeth develop the alveolar ridge - 3rd permanent molar is known as wisdom tooth

floor of nasal cavity

- composed of the hard palate

anterior ethmodial nerve

- contains afferent sensory nerve fibers from cells bodies in trigeminal ganglion - branch of the nassociliary nerve from V1 - provides general sensation to the anterior part of the septum and lateral wall

palatoglossus

- extrinsic ms of the tongue - enters from a superior/lateral position - draws soft palate downward - palatine ms innervated by CN X and forms the palatoglossal arch

styloglossus

- extrinsic ms of the tongue - enters tongue from superior and lateral position - retracts and raises tongue during swallowing

genioglossus

- extrinsic ms of the tongue - extends upward into the tongue from the anterior, inner surface of the mandible - depresses and protrudes the tongue

hypoglossus

- extrinsic ms of the tongue - extends upward into the tongue from the hyoid - flattens the dorsum of the tongue and retracts - important anatomical relations: CN XII, submandibular duct, lingual nerve, and lingual vein pass lateral to its surface; lingual artery passes medially

greater palatine artery

- from descending palatine branch of maxillary a. (external carotid) - supplies antero-inferior part of the septum by passing through the incisive canal of the hard palate

superior labial artery

- from facial artery (external carotid) - supplies the antero-inferior part of the septum

sphenopalatine artery

- from maxillary artery (external carotid) - supplies most of nasal mucosa - largest artery that enters the nasal cavity - passes through the sphenopalatine foramen from the pterygopalatine fossa

anterior and posterior ethmoidal arteries

- from opthalamic artery (internal carotid) - supply antero-superior part of the septum and lateral wall

surface area of the lateral wall

- greatly increased by 3 or 4 scroll-like conchae or turbinates that protrude from the lateral wall - meatuses are the spaces or recesses found inferior and lateral to each concha

nerves to mandibular teeth

- inferior alveolar nerve that enters the mandibular foramen - branch off V3 - cell bodies of afferent fibers located in the trigeminal ganglion

general sensation and taste (afferent) to epiglottic region of the tongue

- internal branch of superior laryngeal n. (from CN X) - cell bodies of these afferents are in the inferior (nodose) ganglion of CN X

maxillary sinuses (in bodies of 2 maxillae)

- largest of the paranasal sinuses - ostium of maxillary sinus is near roof of sinus - drainage: through ostium into posterior end of of the semilunar hiatus into middle meatus - important relation to: orbit, nasal cavity, and roots of the maxillary teeth - develops until permanent teeth has erupted - innervation: anterior, middle, and posterior superior alveolar nerves (branches of V2)

frontal sinuses (in frontal bone)

- often unequal in size; my be multiple on either side - drainage: through frontonasal duct into anterior end of the semilunar hiatus into middle meatus - important superior relation to the oribit - may not appear on x-rays until about age 7 - begin development when anterior ethmoid air cells invade the frontal bone - innervation: supraorbital n. which is a branch off of V1

sphenoid sinuses (in body of sphenoid bone)

- paired sinuses w/ intervening septum, usually very asymmetrical - drainage: through ostium into spehnoethmoidal recess, posterior and superior to superior concha - important relations to: optic nerve, optic chiasm, pituitary, internal carotid artery, cavernous sinus - starts developing at about 2 years old (posterior ethmoid bones invade into sphenoid) - innervation: posterior ethmoidal nerve (branch of V1)

functions of the nose

- respiration - olfaction - reception of secretions from the paranasal sinuses and the nasolacrimal duct - conditioning of the inspired air (filtration of dust particles, humidification, and warming)

injury to CN XII

- results in paralysis and atrophy on the same side of the tongue as the injury - tongue deviates to injured side, when patient protracts tongue

bloody supply to the septum

- richly supplied with blood through branches of both the external and internal carotid arteries 1. anterior and posterior ethmoidal arteries 2. superior labial artery 3. sphenopalatine artery 4. greater palatine artery

nerve supply of maxillary teeth

- superior alveolar nerves (anterior, middle, and posterior branches) - nerves derived from V2 - cell bodies are in trigeminal ganglion

motor innervation of the tongue

- supplied by CN XII (except palatoglossus which is innervated by CN X) - cell bodies found in hypoglossal nucleus

blood supply to mandibular teeth

- supplied by inferior alveolar artery (branch of maxillary artery) that enters the mandibular foramen

blood supply to maxillary teeth

- supplied by posterior superior alveolar artery (branch off the maxillary artery) - also supplied by anterior and middle superior alveolar arteries (branches off infraorbital artery which is a branch off of maxillary)

submandibular duct or Wharton's duct

- terminal part lies below the mucosa of the floor of the mouth, raising it slightly to from the sublingual caruncle found lateral to the frenulum - relationship with lingual n. changes as duct passes from the posterior to anterior portion of the mandible (begins inferior and medial to nerve and passes superior and lateral to it)

Kiesselbach's area

- the site of nosebleeds (epistaxis) - where all arteries that supply the nasal septum, except the posterior ethmoidal artery, anastomose

nasopalatine and other branches to nasal cavity, greater and lesser palatine nerves

1. afferent sensory nerve fibers from cell bodies in trigeminal ganglion 2. postganglionic parasympathetic efferent fibers from cell bodies in pterygopalatine ganglion 3. postganglionic sympathetic fibers from cell bodies in superior cervical ganglion

pterygopalatine nerves

1. afferent sensory nerve fibers from cell bodies in trigeminal ganglion 2. postganglionic parasympathetic efferent fibers from cell bodies in pterygopalatine ganglion to supply lacrimal

summary of nerve fibers associated with the pterygopalatine ganglion

1. afferent sensory nerve fibers from cell bodies in trigeminal ganglion - pass through ganglion without synapse 2. preganglionic parasympathetic efferent fibers from cells bodies in superior salivatory nucleus - synapse in ganglion 3. postganglionic parasympathetic efferent fibers from cell bodies in pterygopalatine ganglion - pass from ganglion to nasal cavity, palate, and lacrimal gland 4. postganglionic sympathetic fibers from cell bodies in superior cervical ganglion of sympathetic trunk - pass through ganglion without synapse

submandibular gland anatomical location

1. expands over the anterior and posterior bellies of the digastric muscle 2. posterior porder is close to the lower part of the parotid gland 3. uncinate process of gland "hooks" around the posterior border of the mylohyoid ms 4. crossed superficially by facial v. 5. facial artery passes deep to this gland and crosses its upper surface`

parotid gland anatomical location

1. extends subcutaneously backward over the anterior portion of the SCM 2. extends over the posterior part of the masseter muscle 3. lies between the ramus of the mandible, the external acoustic meatus, and the mastoid process

paranasal sinuses general features (7)

1. paired, often asymmetric, structures found in the frontal, maxillary, ethmoid, and sphenoid bones 2. develop as outgrowths of the mucosa of the nasal cavities into the adjacent bones replacing the diploe 3. openings into the nasal cavity are sites of original outgrowths 4. most are not positioned to permit optimal gravity drainage 5. only the frontal sinus has gravity drainage in the erect position 6. normally filled with air (bones containing them are called pneumatic bones) 7. mucosa is innervated by branches of the trigeminal nerve

2 major components of hard palate

1. palatine process of maxilla that houses incisive canal that allows passage of vessels and nerves from oral cavity 2. horizontal process of the palatine bone

nerve to pterygoid canal

1. preganglionic parasympathetic efferent fibers from cell boides in superior salivatory nucleus - synapse in pterygopalatine ganglion 2. postganglionic sympathetic fibers from cell bodies in superior cervical ganglion of sympathetic trunk. pass through pterygopalatine ganglion without synapse

structures and openings of the lateral wall of the nasal cavity (sphenoethmoidal and superior meatius

1. sphenoethmoidal recess: space above and posterior to the superior concha - sphenoidal sinus opens into this recess 2. superior meatus: posterior ethmoidal air cells open into this space

inferior medial incisor is usually first to erupt at what age?

6-8 months of age

mucosa of nasal cavity (olfactory and respiratory areas)

after the vestibule, remainder of the cavity is lined with mucous membrane olfactory area upper 1/3 of the mucous membrane respiratory area lower 2/3 of mucous membrane

middle, superior, and supreme (when it exists) conchae and meatuses

c - part of the ethmoid bone m - spaces inferior and lateral to conchae of the same name

intrinsic ms of the tongue

complicated bundles of interlacing fibers with connective tissue septa - produce changes in the tongue's shape for speaking and swallowing

inferior concha and inferior meatus

concha - formed by a separate bone with the same name meatus - space inferior and lateral to inferior concha

lymph from middle (central) third of the tongue

drains bilaterally to: deep cervical nodes

lymph from posterior tongue

drains to deep cervical nodes

lymph from lateral margins of the tongue

drains unilaterally to: submandibular nodes only on the same side

parotid duct (or Stensen's duct)

enters the mouth through the parotid papilla at the level of the junction of the root and crown of the upper second molar tooth

openings of the nasal cavity (internal and external)

external nares - paired openings from the nasal cavity through the nostrils to the outside columella - the lower part of the nasal septum separating the nares internal choanae - paired openings from the nasal cavity to the nasopharynx

what forms the posterior portion of the nares?

fibrous fatty tissue

skin of nasal cavity

found only in the vestibule (entrance to the nasal cavity through the nares)

anatomical features of the tongue

frenulum: anterior midline fold papillae: on dorsum of tongue (contains taste buds) sulcus terminalis: groove on the posterior tongue's surface (posterior to vallate papillae) - separates body of tongue (anterior 2/3) from root of tongue (posterior 1/3) lingual tonsil: on the pharyngeal surface of the tongue, posterior to sulcus terminalis

sinuses that develop during childhood and adolescence

frontal and sphenoidal sinuses

sensory (afferent) innervation of the anterior 2/3 of the tongue (body)

general sensation (pain, touch, temp, etc.) = lingual nerve from V3 whose cell bodies are in the trigeminal ganglion taste fibers (except those on the vallate papillae) = lingual nerve whose cell bodies are in the geniculate ganglion of the facial nerve - join the lingual nerve by way of the chorda tympani

sensory (afferent) innervation of posterior 1/3 of tongue (root and vallate papillae)

general sensation and taste sensation: CN IX whose cell bodies are in the inferior ganglion of IX - also supply the taste buds of vallate papillae

vibrissae

hairs in skin lining the vestibule

sublingual gland anatomical location

inferior to the mucosa in the floor of the mouth superior to the mylohyoid lateral to the sumbmandibular duct and genioglossus ms

external nose

is built around the piriform aperture - the anterior nasal opening of the skull is a pear-shaped opening bounded by 2 nasal bones above and 2 maxillae below on either side

arterial supply to the tongue

lingual artery (from external carotid a.) and its branches: dorsal lingual, sublingual, and deep lingual arteries

cartilaginous skeleton of external nose

lower 2/3 - formed by 2 paired alar cartilages on either side and the septal cartilage in the midline

sinuses present at birth

maxillary and ethmoid - very small

infections from frontal sinuses can easily pass to

maxillary sinuses because both drain into the semilunar hiatus (just at different ends)

structures and openings of nasal cavity: middle meatus

middle meatus: anterior and middle ethmoid air cells, maxillary sinus open into this space - ethmoid bulla: rounded structure formed by middle ethmoid air cells - semilunar hiatus: curved opening anterior to and below ethmoid bulla - anterior ethmoid air cells open in the anterior end of this - frontonasal duct: duct from the frontal sinus - ostium of the maxillary sinus: opens in the region of the psoterior end of the semilunar hiatusillary sinus: opens in the region of the psoterior end of the semilunar hiatus

oral cavity

mouth is divided by the teeth and the gingivae into 1. vestibule of mouth (between the lips and teeth) 2. oral cavity proper (behind the teeth)

nasal septum 3 major components

nasal septum = midline structure that separates 2 nasal cavities 1. perpendicular plate of ethmoid bone 2. vomer 3. septal cartilage

structures and openings of nasal cavity: inferior meatus

nasolacrimal duct opens into this space nasolacrimal duct = drains secretions from lacrimal gland into inferior meatus

sublingual ducts (a dozen or more per gland)

pass from upper border of the gland to the sublingual fold to empty into the oral cavity

nerve supply to parotid gland1

preganglionic efferent fibers - cell bodies: inferior salivatory nucleus - leave brain in CN IX - pass through tympanic branch to lesser petrosal nerve to terminate - terminate in otic ganglion postganglionic efferent fibers: - cell bodes: otic gnaglion - travel through auriculotermporal nerve (from V3) to parotid gland

nerve supply for both submandibular and sublingual glands

preganglionic efferent fibers cell bodies: superior salivatory nucleus travel: via CN VII (leaving brain); pass through chorda tympani and enter lingual nerve (off V3) terminate: submandibular ganglion postganglionic efferent fibers cell bodies: submandibular ganglion terminates/supplies: both submandibular and sublingual salivary glands

Greater petrosal nerve

preganglionic parasympathetic efferent fibers from cell bodies in superior salivatory nucleus

deep petrosal nerve

preganglionic sympathetic efferent fibers from cell bodies in superior cervical ganglion of sympathetic trunk

infections in maxillary sinuses can lead to referred pain in the..

teeth

drainage of lymph from tip and anterior tongue

to submental nodes * medial portion drains billaterally

mucous membrane and cilia...

trap dust particles (mucous) moves particles into nasopharynx posteriorly and inferiorly (directional beating of cilia)

bony skeleton of external nose

upper 1/3 - formed by the 2 nasal bones and adjacent parts of the maxillae and frontal bone