What development occurs during the 3rd week of fetal development?
Inner Ear
- Auditory placode; auditory pit
Middle Ear
-Tubotympanic recess begins to develop
What development occurs during the 4th week of fetal development?
Inner Ear
- Auditory vesicle (otocyst): vestibular-cochlear division
Middle Ear
-5 branchial grooves appear in lower head and neck region on lateral surfaces
Outer Ear
-Tissue thickenings begin to form
What development occurs during the 5th week of fetal development?
Outer Ear
- Primary auditory meatus begins
What development occurs during the 6th week of fetal development?
Inner Ear
- Utricle and saccule present; semicircular canals begin
Outer Ear
-Six hillocks evident; cartilage begins to form
What development occurs during the 7th week of fetal development?
Inner Ear
- One cochlear coil present; sensory cells in utricle and saccule
Outer Ear
- Auricles move dorsolaterally
What development occurs during the 8th week of fetal development?
Inner Ear
- Ductus reuniens present; sensory cells in semicircular canals
- Sensory end organs first appear as localized thickenings of epithelium in the utricle and saccule
Middle Ear
- Incus and malleus present in cartilage; lower half of tympanic cavity formed
Outer Ear
- Outer cartilaginous one-third of external canal formed
What development occurs during the 9th week of fetal development?
Middle Ear
- Three tissue layers at tympanic membrane are present
What development occurs during the 11th week of fetal development?
Inner Ear
- 2.5 cochlear coils present
- Nerve VIII attaches to cochlear duct via ductus reuniens
- Cochlear division of the 8th nerve follows the elongating and coiling of the cochlear duct
What development occurs during the 12th week of fetal development?
Inner Ear
- Sensory cells in cochlea
- Membranous labyrinth complete
- Otic capsule begins to ossify
What development occurs during the 15th week of fetal development?
Middle Ear
- Cartilaginous stapes formed
What development occurs during the 16th week of fetal development?
Inner Ear
- Otic capsule begins to ossify
Middle Ear
- Ossification of malleus and incus beings
What development occurs during the 18th week of fetal development?
Middle Ear
- Stapes begins to ossify
What development occurs during the 20th week of fetal development?
Inner Ear
- Maturation of inner ear; inner ear adult size
Outer Ear
- Auricle is adult shape but continues to grow until age 9
What development occurs during the 21st week of fetal development?
Middle Ear
- Meatal plug disintegrates, exposing tympanic membrane
What development occurs during the 30th week of fetal development?
Middle Ear
- Pneumatization of tympanum
Outer Ear
- External auditory canal continues to mature until age 7
What development occurs during the 32nd week of fetal development?
Middle Ear
- Malleus and incus complete ossification
What development occurs during the 34th week of fetal development?
Middle Ear
- Mastoid air cells develop
What development occurs during the 35th week of fetal development?
Middle Ear
- Antrum is pneumatized
What development occurs during the 37th week of fetal development?
Middle Ear
- Epitympanum is pneumatized
- Stapes continues to develop until adulthood -
- Tympanic membrane changes relative position during first 2 years of life
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Lecture 1- Embryology37
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Lecture 218
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Lecture 3- HL in children12
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Lecture 4- Early Identification of Hearing Loss23
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Lecture 5- Pediatric Speech Testing7
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Lecture 6- Pseudohypacusis12
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Figure 2.119
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Lecture 7- Management fo HL in Children14
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Lecture 8- Intro to Educational Audiology32
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Lecture 9- Case Management & Planning26
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Lecture 10- Pediatric Audiology25
