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Flashcards in embryo 1 Deck (44)
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1

week 4 develops what

5 facial primorida

2

what are the 5 facial primorida

frontonasal prominence- 1
maxillary prominences -2
mandibular prominences- 2

3

Prominences form due to what

proliferation of neural crest

4

neural crest cells from what make up the maxillary and mandiublar prominences

1st pharyngeal arch

5

neural crest cells from what make up frontonasal prominances

midbrain and rostal hindbrain

6

most facial structures develop when

weeks 4-8

7

1st ossification center in skull appears when

month 3

8

end of 4th week: 2 ectodermal thickenings develop within frontonasal prominence form what

the nasal placodes

9

Mesenchyme surrounding the placodes proliferates, forming elevations forming what

Medial nasal prominences (2)
Lateral nasal prominences (2)

10

Epithelium of nasal placodes sinks down into underlying mesenchyme to form depressions forming what

nasal pits (the future nostrils (nares))

11

Both nasal pits deepen and expand dorsally into turning into _______, which will form the right and left nasal cavities

nasal sacs

12

Nasal cavities are separated from oral cavity by ________, which ruptures at end of _______ . Nasal & oral cavities now in communication through primordial _______

oronasal membrane, week 6, choanae

13

With development of _______, we have the definitive choanae separating nasal cavities from nasopharynx

secondary palate

14

Roof of nasal cavity is invaded by specialized cells that grow out of forebrain (neuroectoderm) to form what?

olfactory epithelium

15

Mandibular prominences fuse at midline first; lower jaw & lower lip form before or after upper jaw?

before

16

At first, a cleft exists between the lateral nasal prominences and the maxillary prominences: the what?

nasolacrimal groove

17

When the medial nasal prominences fuse (early in 6th week), they form the ________

intermaxillary segment:

18

intermaxillary segment cossets of what 3 things

-Philtrum of upper lip (labial component)
-Premaxillary part of maxilla (upper jaw component) – 4 incisors &
associated gingiva
-Primary palate (palatal component; the 1° palate is only the most anterior portion of the hard palate)

19

the remainder of the hard palate + the soft palate (+ uvula) is called what

Secondary palate =

20

Week 6: Two plates of mesenchyme –__________ – extend medially from the maxillary prominences

lateral palatine processes

21

_________ marks where secondary palate fuses with primary palate; used to indicate anterior & posterior palatal defects

incisive foramen

22

_________ marks where lateral palatine processes fused together

Median palatine raphe

23

Primary palate and anterior portion of secondary palate will ossify forming the bony _______

hard palate

24

Posterior-most portion of the secondary palate does not ossify – extends posteriorly to _________

form the soft palate & uvula

25

Formation of the palate takes place weeks

6-12

26

Primary palate forms from fusion of what

medial nasal prominences

27

Secondary palate forms from what

fusion of two lateral palatine processes (medial extensions of maxillary prominences)

28

cleft lip is what

An anterior palatal defect caused by failure of medial nasal prominences to fuse with maxillary prominences on one or both sides

29

cleft palate

A posterior palatal defect caused by failure of lateral palatine processes to fuse

30

which part of ear is first to develop

inner ear