Dev Of The Nose And Face Flashcards
What 3 things drive dev of the face?
Expansion of the NT
Appearance of complex tissue systems associated with gut tube and outflow of dev heart
Dev of sense organs
Where do neural crest cells originate from?
Neuroectoderm
What are the 4 major features of the face?
Palpebral fissure, oral fissure, nares, philtrum
What is the primordia of the eyes?
FNP
What does the stomatodeum give? Why?
Buccopharyngeal membrane- mouth
No mesoderm between the endo and ectoderm here
What does the FNP give?
Forehead, bridge of nose, nose, philtrum
What does the maxillary prominence give?
Cheeks, lat upper lip and jaw
What does the mandibular prominence give?
Lower lip and jaw
How does the nose form?
- Nasal placodes appear on FNP
- Sink into nasal pits
- Med and lat nasal prominences form on either side of pits
- Maxillary prominences grow med pushing nasal prominences together
- Maxillary prominences fuse with med
- Med nasal prominences fuse in midline
How are the nasal and oral cavities separated?
Med nasal prominences fuse -> creating intermaxillary segment (primary palate)
Secondary palate derived from palatal shelves (from maxillary prominence)- fuse in midline one mandible grown
What must repute to allow oral and nasal cavities to be continuous?
Oronasal membrane
What causes lat cleft lip?
Failure of fusion of med nasal prominences and maxillary prominences
What causes cleft lip and palate?
Lat cleft lip + failure of palatal shelved to meet in midline
Where do the eyes dev from?
Outpocketings of forebrain. Grow to meet optic placodes (lens)
What gives rise to the lens and the retina?
Lens- optic placode
Retina- diencephalon (forebrain)
What pushes the eyes from the side of the face to the middle? Why necessary?
Growing facial prominences
To allow binocular vision
Where does the EAM dev from? And the auricle?
1st P CLEFT
1st and 2nd PA
Where do the ears initially dev? Why to they end up where they do?
The neck, ascend with the growing mandible
How does the inner ear dev?
Otic placodes invaginate giving auditory vesicles -> cochlea and semicircular canals
What is fetal alcohol syndrome? Incidence? Characteristics?
Alcohol abuse during preganany. NC and brain dev v sensitive to alcohol.
1/100 births
Low nasal bridge, small philrum, head and eye openings, flat midface, thin upper lip, epicanthal folds.
