UNIT 2 formation of facial cavities

UNIT 2 formation of facial cavities

Done

What happens as a result of maxillary prominencens medial growth

Medial nasal prominences merge at surface + deep

What does the merging of 2 medial nasal prominences form

Intermaxillary segment

What is the intermaxillary segment comprised of

Labial component

Maxillary component

Palatal component

What does the labial component form Of intermaxilalry segfment

superior lip philtrum

What does the maxilary compoent of the intermaxillary segment carry

4 incisors

What does the palatal comoennt of the intermaxillary segment form

Triangular primary palate

What is the intermaxillary segment continuous with

Ventral nasal septum

What divides the priary and secondary palate

Incisal foramen

When does development of paalte begine

Week 5

When does palate fusion finish

Weekm 12

What is the palate formed by

Primary palate

Secindary palate

What is the primary palate aka

Intermaxillary segment

what is the secondary paalte formed by

2 palatine shelves / lateral palatine processes

where do the palatine shelves initially frow

Downward alongside tongue

Where do the palatine shelves move to

Elevate to horizontal position above tongue

(When they form the secondary palate)

What happens if the elevation +fusion of the palatine shelves fails

Cleft palate

What is the triangular primary palate aka

Incsive foramne

What do the palatine shelves fuse with anteriorly

Incisivce foramen

What is the midline betwen the primary adn secondary palate

Incisive foramen

What happens to the nasal septum as the palatine shelves fuse

Nasal septum grows caudally and joins the newly formed palate

Nasal and oral cavity development

Done

Where do the nasal and maxillary prominences fuse

On the surface and depth of stomodeum

What membrane is torn at the end of the 3rd week

Buccopharyngeal membrane

what does tearin g of the buccopharyngeral membrane connect

Ectodermal oral cavity with endodermal foregut

What does the growth of the nasal prominences split

Nasal cavity from oral cavity

what does the growth of nasal prominences and their penetration inot the underlying mesenchyme cause

Nasal pit to deepen

What membrane pslits the nasal pits from the oral cavity

Oronasal / bucconasal membrane

What is openly connected after the oronasal membrane breaks down

Nasal and oral cavities

What new foramina is formed to connect the oral and nasal cavities

Primitive choanae

After the secondary palate formation, where do the internal nostrils shift Into

Into nasopharynx

Via ? Do the the internal nostrils shift

Definitive choanae

After the definitve choanae are formed and in place what is formed

Definitive nasal cavity

Where does the nasal septum ascend from

Medial nasal prominence with the palate

What do the lateral walls of the nasal cavity develop

Superior, middle and inferior conchae

What does the ectodermal epithelium in the roof of nasal cavity become

Specialised olfactory epithelium

What gives rise to the olfactory nerve fibers

Olfactory cells in olfactory epithelium

What do the olfactory nerve fibers grow into

Olfactory bulbs

When dothe paranasal sinuses form

Postnatally

What do the paranasal sinuses form as

Sacs of the nasal cavity

What is the final form of the nasal and oral cavities

(3 things)

Primary and secondary palates

Choanae at their junction

Pharynx

Look

Dome

What divides the anterior and posterior clefts

Incisive foramen

What is anterior to the incisive foramen

(3 things)

Lateral cleft lip

Cleft maxilla

Cleft between 1 and 2 palate

What are the anterior clefts formed by

Lack of fusion of amxillary prominence with medial nasal prominence

What are tge clefts posterior to the incisive froamen

2 thinfs

Cleft secondary palate

Cleft uvula

What does a cleft palate a result of

Lack of palatine shelves fusion

What can cause lack of palatien shelf fusion

• shelf too small

• Shelf does not elevate

• Micrognathia

What is micrognathia

Lower jaw is underdeveloped —> receding chin

What is produced from a failure of maxillary prominence to merge with corresponding lateral nasal prominence

oblique facial cleft

What does a onlique facial cleft cause

Nasolacrimal duct to be exposed

What is produced from a failure Of merging of 2 medial nasal prominence in middle line

Median cleft lip

Which has lower frequency

Isolated cleft palate

Cleft lip

Cleft palate

What can cause clefts

Exposure to teratogenic compounds e.g anticonvulsant medication

Where does failsure of fusion of maxillary prominence and medial nasal prominence affect up to (3 things)

Lip

Alveolar bone

Primary palate

What causes cleft of secondary palate

Incomplete fusion of 2 palatine shelves

What does failure of fusion between maxillary prominence wth medial nasal prominence cause

Cleft lip