17b. Development of the organ of hearing.

Question 1

Development of the membranous labyrinth
-> What will develop into membranous labyrinth? When?

Answer 1

Otic vesicle
-> 4th week

Question 2

Development of the membranous labyrinth (4th week)
-> Identify

Answer 2

Question 3

What happen during Development of the vestibular and cochlear ganglia

Answer 3

The statoacustic = vestibulocochlear ganglion later splits into vestibular and cochlear parts.

Question 4

development of the otic vesicle
-> What happen during 6th week?

Answer 4

Semicircular canals develop from the utricular vesicle

Question 5

Development of the bony labyrinth
-> Identify

Answer 5

Question 6

Development of the bony labyrinth
-> What happen during 6th month?

Answer 6

Question 7

Development of the bony labyrinth
-> What happen during 10th week?

Answer 7

cavitation of the otic capsule
-> Scala tympany and scala vestibuli

Question 8

The pharyngeal apparatus
-> Each pharyngeal arch has its own ___ (4 things)

Answer 8

 aortic arch artery
 cartilage
 myoblast
 cranial nerve

Question 9

Development of the middle ear
-> What arises from 1st Pharyngeal cleft?

Answer 9

External acustic meatus

Question 10

Development of the middle ear
-> What arises from 1st Pharyngeal pouch?

Answer 10

1. Tubotympanic recess
2. Tympanic membrane

Question 11

Development of the middle ear
-> What arises from Tubotympanic recess (1st pharyngeal pouch)?

Answer 11

• Distal part – tympanic cavity antrum mastoideum
• Proximal part - tuba auditiva

Question 12

Development of the middle ear
-> What arises from Tympanic membrane (1st Pharyngeal pouch)?

Answer 12

1. Outer ectoderm layer
2. Middle mesodermal layer
3. Inner endodermal layer

Question 13

Development of the middle ear
-> What are the 2 types of cartilage?

Answer 13

I. Meckel cartilage
II. Reichert cartilage

Question 14

Development of the middle ear
-> Meckel cartilage gives off ___ (2 structures)

Answer 14

1. Malleus
2. Incus

Question 15

Development of the middle ear
-> Reichert cartilage gives off ___

Answer 15

Stapes

Question 16

Development of the middle ear
-> Mesenchyme filling the tympanic cavity till which month?

Answer 16

the 8th month

Question 17

Development of the middle ear
-> Identify

Answer 17

auditory ossicles

Question 18

What give rise to tympanic muscle?

Answer 18

1st pharyngeal arch myoblast (n.V.)

Question 19

What give rise to stapedius muscle?

Answer 19

2nd pharyngeal arch myoblast (n. VII)

Question 20

What do mensenchymes give rise to?

Answer 20

ligaments

Question 21

Tympanic cavity at birth and first years of age
-> What are included in dorsal extension?

Answer 21

antrum tympanicum – pneumatization - mastoid cells

Question 22

Development of the pinna (6th week)
-> What do 1 -> 6 arise from?

Answer 22

Question 23

What happen during Development of the pinna?

Answer 23

During development the auricle moves from the neck to its final location. Developing ear remnants (preauricular tags) are congenital anomalies seen along this route.