embryo 1

Question 1

week 4 develops what

Answer 1

5 facial primorida

Question 2

what are the 5 facial primorida

Answer 2

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

Question 3

Prominences form due to what

Answer 3

proliferation of neural crest

Question 4

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

Answer 4

1st pharyngeal arch

Question 5

neural crest cells from what make up frontonasal prominances

Answer 5

midbrain and rostal hindbrain

Question 6

most facial structures develop when

Answer 6

weeks 4-8

Question 7

1st ossification center in skull appears when

Answer 7

month 3

Question 8

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

Answer 8

the nasal placodes

Question 9

Mesenchyme surrounding the placodes proliferates, forming elevations forming what

Answer 9

Medial nasal prominences (2)

Lateral nasal prominences (2)

Question 10

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

Answer 10

nasal pits (the future nostrils (nares))

Question 11

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

Answer 11

nasal sacs

Question 12

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

Answer 12

oronasal membrane, week 6, choanae

Question 13

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

Answer 13

secondary palate

Question 14

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

Answer 14

olfactory epithelium

Question 15

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

Answer 15

before

Question 16

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

Answer 16

nasolacrimal groove

Question 17

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

Answer 17

intermaxillary segment:

Question 18

intermaxillary segment cossets of what 3 things

Answer 18

-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)

Question 19

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

Answer 19

Secondary palate =

Question 20

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

Answer 20

lateral palatine processes

Question 21

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

Answer 21

incisive foramen

Question 22

_________ marks where lateral palatine processes fused together

Answer 22

Median palatine raphe

Question 23

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

Answer 23

hard palate

Question 24

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

Answer 24

form the soft palate & uvula

Question 25

Formation of the palate takes place weeks

Answer 25

6-12

Question 26

Primary palate forms from fusion of what

Answer 26

medial nasal prominences

Question 27

Secondary palate forms from what

Answer 27

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

Question 28

cleft lip is what

Answer 28

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

Question 29

cleft palate

Answer 29

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

Question 30

which part of ear is first to develop

Answer 30

inner ear

Question 31

Develops as a bilateral thickening in surface ectoderm at the level of the caudal hindbrain called what

Answer 31

otic placodes (2)

Question 32

Ectoderm invaginates in each placode, forming an _______, the edges of which pinch off to form an _______ that separates from surface ectoderm  will become the _________ for each ear

Answer 32

otic pit, otic vesicle, membranous labyrinth

Question 33

Diverticulum extends from otic vesicle to form the _________

Answer 33

endolymphatic duct & sac

Question 34

Otic vesicle can be divided into two regions:

Answer 34

``` Utricular region (dorsal)  utricle + semicircular ducts Saccular region (ventral)  saccule + cochlear ducts ```

Question 35

The cochlear duct grows out as extension from ________ and coils to form the membranous cochlea

Answer 35

saccular region

Question 36

Cells in walls of coiled duct form the _______

Answer 36

spiral organ of Corti

Question 37

Cell bodies of CN VIII migrate along coils of cochlear duct and form the ________

Answer 37

spiral ganglion

Question 38

Vacuoles develop in cartilage surrounding the cochlear duct and unite to form the ________ (two divisions: __________ __________, both filled with perilymph

Answer 38

perilymphatic space, scala vestbuli and scala tympani

Question 39

_______ surrounding cochlear duct ossifies to form the bony labyrinth encasing the inner ear structures

Answer 39

Cartilage

Question 40

middle ear...1st pharyngeal pouch expands as the __________ and gives rise to the pharyngotympanic (Eustachian) tube, tympanic cavity, mastoid antrum, & endoderm of tympanic membrane

Answer 40

tubotympanic recess

Question 41

middle ear: 1st and 2nd pharyngeal arches form the _______

Answer 41

auditory ossicles

Question 42

1st pharyngeal groove forms the _______

Answer 42

external acoustic meatus

Question 43

Surface ectoderm invaginates with 1st pharyngeal groove and meets endoderm extension of 1st pharyngeal pouch to form 1st pharyngeal membrane forming what

Answer 43

= tympanic membrane

Question 44

external ear Develops from what?

Answer 44

auricular hillocks: