Template:Hearing timeline table

From Embryology
Hearing Timeline
Developmental Time Event
Week 9 Mesenchyme surrounding membranous labryinth (otic capsule) chondrifies.
Week 12-16 Capsule adjacent to membranous labryinth undegoes vacuolization to form a cavity (perilymphatic space) around membranous labrynth and fills with perilymph.
Week 18 ectodermal plug in external auditory meatus breaks down.
Week 16 - 24 Centres of endochondral ossification appear in remaining cartilage of otic capsule form petrous portion of temporal bone. Continues to ossify to form mastoid process of temporal bone.
Week 18 - 22 Organ of corti structural elements develop. (GA 20 - 24 weeks)
26 weeks human brainstem auditory pathway is anatomically formed.
28 weeks AABR can be recorded.
3rd Trimester Vibration acoustically of maternal abdominal wall induces startle response in fetus.
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