2nd semester: Embryology of EAR, NOSE, TONGUE

Question 1

Internal arises from thickening of surface ______ at level of developing brainstem in myencephalon

Answer 1

Ectoderm

Question 2

Thickening of ectodermal surface -> ______ -> Otic pit

Answer 2

Otic placade

Question 3

What portion will become the membranous labyrinth?

Answer 3

Otic vesicle

Question 4

The Otic Vesicle will have 2 compartments. The VENTRAL component will become the _______

Answer 4

A. Saccule [Receptor for STATIC EQUILIBRIUM -> linear motion -> MACULA]
B. Cochlear duct [Receptor for HEARING -> ORGAN OF CORTI]

Question 5

The Otic Vesicle will have 2 compartments. The DORSAL component will become the _______

Answer 5

A. Utricle [saccule w/ macula -> linear motion]
B. Semicircular ducts [receptor for CIRCULAR MOTION -> crista ampullaris]
C. Endolymphatic duct [diverticulum as otic vesicle DISENGAGE from ectoderm]

Question 6

Middle arises from _____

Answer 6

Endoderm [1st pharyngeal pouch]

Question 7

The 1st phrayngeal pouch is divided into 2. The DISTAL part forms the ______

Answer 7

tympanic cavity

Question 8

The formation of the ossicles and muscles are derived from _____

Answer 8

mesoderm

Question 9

The 1st phrayngeal pouch is divided into 2. The PROXIMAL part forms the ______

Answer 9

auditory tube/eustachian tube [connects to the nasopharyngeal part]

Question 10

The ____ is directly connected to the tympanic membrane while ____ is to the oval window of entry to inner ear

Answer 10

Malleus

Stapes

Question 11

Stapes arises from the cartilage of ______

Answer 11

2nd pharyngeal arch

Question 12

Skeletal muscles and their attachment:
Tensory tympani: ________
________: attached to stapes

Answer 12

attached to malleus

stapedius muscle

Question 13

The eardrum/tympanic membrane is the boundary between ______

Answer 13

OUTER and INNER ear

Question 14

The pinna/auricle is the external portion of the ear.
The pharyngeal cleft -> gives rise to the ____
The pharyngeal arch -> gives rise to ____

Answer 14

skin [ectoderm]

elastic cartilage [mesoderm]

Question 15

The ____ solid component of pharyngeal cleft and will disintegrate. IF NOT, will form congenital conductive deafness.

Answer 15

Meatal plug

Question 16

The ____ will communicate with middle ear through tympanic membrane

Answer 16

Meatal plug

Question 17

The eardrum is made of
epithelial lining from -> 1st pharyngeal cleft
endothelial lining from -> 1st pharyngeal pouch
Layer of CT -> ___ and ___ pharyngeal arches

Answer 17

1st

2nd

Question 18

The nose arises from ___

Answer 18

surface ectoderm

Question 19

When will the nose start to develop?

Answer 19

5th week of gestation

Question 20

The developing ____ will eventually become the oral cavity

Answer 20

stomodeum

Question 21

The developing telencephalon will become the ______

Answer 21

cerebrum

Question 22

nasal placode -> depression -> ___ -> nasal sac -> ______

Answer 22

nasal pit

nasal cavity

Question 23

nose: The MEDIAL nasal swelling will become the _____

Answer 23

nasal septum

Question 24

The nasal septum will be continuous with ____

Answer 24

columella

Question 25

nose: The LATERAL nasal swelling will become ______

Answer 25

ALA OF NOSE [nostrils]

Question 26

What is the special type of lining that covers the nasal cavity?

Answer 26

Ectodermal epithelium [arises from nasal placode and becomes the olfactory epithelium; olfactory placode]

Question 27

The tongue arises from what germ layer?

Answer 27

ENDOdermal layer [1st pharyngeal arch]

Question 28

When does the tongue start to develop?

Answer 28

4th week of gestation

Question 29

Tongue: The medial swelling from the 1st phrayngeal arch will become the _______

Answer 29

Tuberculum impar

Question 30

Tongue: swellings on the lateral side of tuberculum impar will merge and form the _____ of the tongue

Answer 30

Anterior 2/3

Question 31

The point of fusion of the 2 lateral lingual swelling is ______

Answer 31

median sulcus of the tongue

Question 32

what are the 5 pharyngeal arches?

Answer 32

1,2,3,4,6 | no 5 kasi mag disintegrate lang siya or hindi mag develop

Question 33

The posterior 1/3 of the tongue will arise from

Answer 33

hypobonchial eminence

Question 34

What is the fate of the 2nd pharyngeal arch associated with the tongue?

Answer 34

Capula

Question 35

Majority of the 3rd and 4th pharyngeal arch develops into the

Answer 35

hypobranchial eminence [overshadows the capula]

Question 36

Tongue: point of fusion between the anterior 2/3 & posterior 1/3 is a V-SHAPED structure known as

Answer 36

Terminal Sulcus

Question 37

What important parts are found in the lingual papillae?

Answer 37

Taste buds

Question 38

When does the lingual papillae develop?

Answer 38

around 11th to 13th week