9. Developmental defects (embryology) Flashcards
how does lateral cleft lip arise?
failure of fusion of medial nasal prominence and maxillary prominence
how do cleft lip and cleft palate arise?
lateral cleft lip (failure of fusion of medial nasal + maxillary prominence) combined with failure of palatal shelves to meet in midline
what does lateral cleft lip involve?
primary palate (nasal and oral cavity fused)
what does cleft lip and cleft palate involve?
primary and secondary palate (separates oral and nasal cavities)
what does the frontonasal prominence form?
T zone:
forehead
bridge of nose
medial and lateral nasal prominences
what is the fate of the medial nasal prominence?
philtrum
primary palate (only separates opening of cavities)
MID upper jaw
what is the fate of the lateral nasal prominence?
sides of the nose
what is the fate of the maxillary prominence?
cheeks
lateral upper lip
lateral upper jaw
secondary palate (further back - soft palate)
what is the fate of the mandibular prominence?
lower jaw and lip
where do the eyes development begin?
4th week
out-pocketings of forebrain
how do the out-pocketings of the forebrain (eyes) develop?
grow out to make contact with overlying ECtoderm (outermost)
what forms the lens of the eyes?
optic placodes
