E1 Dev Of Face, Nose, Ears, Eyes Flashcards
5 Facial primordia develop as bulging prominences around stomodeum:
- Frontonasal Prominence (1)
- Maxillary Prominences (2)
- Mandibular Prominences (2)
End of 4th week: 2 ectodermal thickenings develop within frontonasal prominence:
Nasal Placodes
Mesenchyme surrounding the nasal placodes proliferates forming elevations:
Medial Nasal Prominences (2)
Lateral Nasal Prominences (2)
Epithelium of nasal placodes sinks down into underlying mesenchyme to form depressions:
Nasal pits (future nostrils)
Both nasal sacs will form the _____
Right and left nasal cavities
The _____ separates nasal cavities form oral cavity; it ruptures at end of week 6 to form communication between cavities through _____
Oronasal Membrane
Primordial Choanae
Development of secondary palate establishes the definitive ____ separating nasal cavities from nasopharynx.
Choanae
_____ gives rise to Olfactory epithelium
Neuroectoderm
Cleft between lateral nasal prominences and maxillary prominences. Lost when lateral nasal prominences fuse with maxillary prominences.
Nasolacrimal Groove
Ectoderm proliferates into underlying mesenchyme and forms a solid rod that separates from surface and canalizes to become ____. Superior end forms a sac, inferior end opens up into inferior meatus of nasal cavity.
Nasolacrimal Duct
Medial nasal prominences fuse -> Intermaxillary Segment:
- Philtrum of upper lip
- Premaxillary part of maxilla
- 4 incisors/gingiva
- Primary Palate (most anterior part of hard palate)
Remainder of hard palate and soft palate and uvula
Secondary Palate
Marks where secondary palate fuses with primary palate; used to indicate anterior and posterior palatial defects
Incisive Foramen
Marks where lateral palatine processes fused together
Median Palatine Raphe
Anterior palatal defect caused by failure of medial nasal prominences to fuse with maxillary prominences on one or both sides.
Cleft Lip (w or w/o Cleft Palate)
When tongue doesn’t drop and blocks fusion of lateral palatine processes, a _____ will result.
Cleft Palate
Inner ear develops as a bilateral thickening in surface ectoderm at level of caudal hindbrain:
Otic Placodes (2)
Ectoderm invaginates in each Otic Placode, forming an ____, the edges of which pinch off to form an ____ that separates from surface ectoderm to eventually become ____.
Otic Pit
Otic Vesicle
Membranous Labyrinth
Diverticulum extends from otic vesicle to form the _____
Endolymphatic Duct and Sac
Utricle + Semicircular Ducts =
Utricular Region
Saccule + Cochlear Ducts
Saccular Region
Grows out as extension from saccular region and coils to form the membranous cochlea
Cochlear Duct
Vacuoles develop in cartilage surrounding cochlear duct and unite to form the ____.
Perilymphatic Space (Scala Vestibuli and Scala Tympani, both filled with perilymph)
The cochlear duct grows out as extension from saccular region and coils to form the membranous cochlea. Cells in walls of coiled duct form the ____
Spiral Organ of Corti
Cell bodies of CN VIII migrate along coils of cochlear duct and form ____
Spiral Ganglion
External ear (auricle/pinna) develops from _____ (mesenchymal proliferations surrounding 1st pharyngeal groove)
Auricular Hillocks
Key hole appearance of iris due to failure of retinal fissure to close in 7th week
Coloboma
Eyelids develop from ______. They are fused until they open in week 28.
Mesenchyme (migrated neural crest)
