Head & Neck Development

Question 1

Five enlargements (formed early in 4th week) that give rise to facial features

Answer 1

Single frontonasal prominence

Paired maxillary prominence

Paired mandibular prominence

Question 2

facial prominences are derived from _______ and appear around the __________ (primordial mouth)

Answer 2

Neural crest cells

stomodeum

Question 3

frontonasal prominence surrounds _________ and forms ________, _________, and __________

Answer 3

ventrolateral part of forebrain

optic vesicles, forehead, and boundary between stomodeum and nose

Question 4

maxillary prominences form

Answer 4

lateral boundaries of stomodeum

Question 5

mandibular prominences form

Answer 5

lower boundary of stomodeum

Question 6

first facial structures to form?

Answer 6

lower jaw and lower lip

Question 7

_______ are on frontal surface of frontonasal prominence and _____ are lateral

Answer 7

nasal placodes

lens placodes

Question 8

at ___ days prominences have shifted

Answer 8

33

Question 9

at ____ days medial nasal prominences merge with each other and maxillary prominences

Answer 9

48

Question 10

Nose development (1):

mesenchyme in placodes form _______

nasal placodes then turn in to _______

nasal prominences are separated from maxillary prominences by _______

Answer 10

nasal prominences (medial and lateral around each placode)

nasal pits

nasolacrimal groove

Question 11

nasal prominences eventually give rise to _____

nasal pits deepen and eventually give rise to _____

Answer 11

nares

nasal cavity

Question 12

Nose development (2):

mesenchyme deepens nasal pits to form ______
separated from mouth by __________

______,______, and ________ develop in lateral walls

ectodermal epithelium form ____________
which specializes into____________

Answer 12

nasal sacs
oronasal membrane

superior, middle, and inferior conchae

olfactory epithelium
olfactory nerves

Question 13

what grows toward developing oral cavity to eventually connect?

Answer 13

nasal sac

Question 14

when do sinuses develop?

Answer 14

late near end of pregnancy or after birth

Question 15

what are the five sinuses?

Answer 15

paranasal - grows later to change face and voice tone during puberty

maxillary - fully developed once mature teeth are in

frontal - develops after birth from ethmoid sinus extensions

sphenoid - develops after birth from ethmoid sinus extensions

ethmoid - small at birth, grows about age 6

Question 16

when do ears begin developing?

Answer 16

end of 5th week

Question 17

ear development begins with

Answer 17

six auricular hillocks

Question 18

where are the six auricular hillocks?

Answer 18

3 on each side, near the 1st and 2nd pharyngeal arches

Question 19

the auricular hillocks are the primordium of the

Answer 19

external acoustic meatus

Question 20

ears are first located in _____ and move ___ due to _________

Answer 20

neck

up

mandible developing

Question 21

when do lips develop?

Answer 21

7 to 10 weeks

Question 22

Four major parts of lip development

Answer 22

1. medial and lateral nasal prominences fuse with maxillary prominences
2. form intermaxillary segment
3. form upper jaw and lip
4. extensions of maxillary prominences remain as philtrum

Question 23

what develops from the intermaxillary segment (lip development)

Answer 23

deep median part of upper lip
gingiva
primary palate

Question 24

palatogenesis happens from _____ weeks

Answer 24

6 to 12

Question 25

the primary palate forms from the _______ which then forms the _________

Answer 25

median palatine process

premaxillary part of the maxilla

Question 26

the premaxillary part of the maxilla becomes the

Answer 26

adult hard palate anterior to the incisive fossa

Question 27

the secondary palate forms from the _______ which forms the _________

Answer 27

maxillary prominence

lateral palatine processes

Question 28

lateral palatine processes fuse in the __________ with the ________ and __________

Answer 28

median palatine raphe

nasal septum

primary palate

Question 29

endochondral bone formation in the lateral palatine processes forms the _______

Answer 29

hard palate

Question 30

posterior process of the secondary palate does not ossify and forms the ______ and _______

Answer 30

soft palate and uvula

Question 31

Palate development, in short:

primary palate becomes the ________

secondary palate becomes the ________

Answer 31

premaxillary part of maxilla

lateral palatine processes

Question 32

anomaly that appears through the lip and separates anterior and posterior part of palate

Answer 32

cleft lip (with or without cleft palate of alveolar part of maxilla)

Question 33

cleft lip is a _________ anomaly

Answer 33

anterior cleft

Question 34

anomaly that extends through soft and hard palate, and separates anterior AND posterior parts of the palate

Answer 34

posterior cleft anomaly

Question 35

why are lower lip clefts less common?

Answer 35

because lower jaw fuses earlier than upper

Question 36

failure of maxillary prominence on affected side to fuse with medial nasal prominences

Answer 36

unilateral cleft lip

Question 37

maxillary prominences fail to fuse with medial nasal prominences

Answer 37

bilateral cleft lip