Understanding development of the human ears in life

1. DEVELOMPMENT OF
THE EAR
Dr Shittu LAJ

2. objectives
 1. Define otic placode, otic pit, otic vesicle,
endolymphatic duct and sac, spiral organ (of
corti), and semicircular ducts.
 2. Discuss the embryological basis of the
following congenital anomalies;
endolymphaticus, deafness etc.

3. THE EAR
 - Three Anatomical Parts -
 - external
 - middle
 - internal

4. Development of the Inner Ear
 Early 4th week - From Myelencephalon
 Otic placode  otic pit  otic vesicle (otocyst)
 Endolymphatic duct and sac  utricular and
saccular portions
 Cochlea

6. Development of Middle
Ear:
 Tubotympanic recess  (Dis.) Tympanic
cavity  (Prox.) Eustachian tube
 Tympanic Cavity  Auditory ossicles
(Malleus, Incus and Stapes)
 Mastoid antrum and mastoid processes

7. Development of External Ear:
 The external acoustic Meatus - develops from
the dorsal end of the first branchial groove.
 -NB: Primordium of Tympanic membrane is the
first branchial membrane

8. Congenital Anomalies of the
Ear.
 Hearing loss/deafness
 Endolymphaticus

9.  Tympanic membrane develops from -
ectoderm
 - mesoderm
 - endoderm
 - auricle develops from six mesenchymal
swellings
 - auricular hillocks

10.  Tympanic membrane develops from -
ectoderm
 - mesoderm
 - endoderm
 - auricle develops from six mesenchymal
swellings
 - auricular hillocks