Prenatal Craniofacial Development

Question 1

~____ days, head& neck region comprises ~ half of embryo

Answer 1

22

Question 2

~22days, head& neck region comprises ~ ____ of embryo

Answer 2

half

Question 3

During ____ week, ventral mesoderm condenses into a series of segmented bilaterally paired, mesenchymal swellings

Answer 3

4th

Question 4

During 4th week, ___________ condenses into a series of segmented bilaterally paired, mesenchymal swellings

Answer 4

ventral mesoderm

Question 5

Oropharyngeal membrane (OM) breaks down during the ____ week of development

Answer 5

4th week

Question 6

Initially, _____ prominences (tissue masses) surround the stomodeum

Answer 6

five

Question 7

Which 2 processes are both paired structures> grow ventro-laterally around the OM?

Answer 7

Maxillary and mandibular

Question 8

The majority of the growth and morphological change in facial tissue masses is driven by the invading ________ mesenchyme.

Answer 8

cranial neural crest-derived

Question 9

the paired first pharyngeal arches only give rise to the _______ processes.

Answer 9

mandibular

Question 10

______ processes originate as separate (delayed) swellings rostral to the mandibular processes; Invaded by distinct population of late migrating CNCC

Answer 10

Maxillary

Question 11

Formation and invagination of nasal placodes (thickening of ectoderm) in _________

Answer 11

Frontonasal Prominence (FNP)

Question 12

Induction and invagination of ________ similar to neural plate induction and invagination

Answer 12

nasal placodes

Question 13

In the morphogenesis of the midface, merging occurs ______

Answer 13

1st

Question 14

(joining of two masses already partly in contact)

Answer 14

Merging

Question 15

• Merging of Maxillary (MXP) & Lateral Nasal Processes (LNP)

* _____ merging of Mandibular Processes (MNP)

Answer 15

Medial

Question 16

Which 2 processes merge together?

Answer 16

Maxillary (MXP) & Lateral Nasal Processes (LNP)

Question 17

In the morphogenesis of the midface, fusion occurs ______

Answer 17

2nd

Question 18

(joining of two separate tissue masses)

Answer 18

Fusion

Question 19

Contact-dependent fusion between ____ and _____ ØForms the primary palate and nares (nostrils)

Answer 19

MNP and MXP/LNP

Question 20

Contact-dependent fusion between MNP and MXP/LNP

ØForms the _____ and ______

Answer 20

primary palate and nares (nostrils)

Question 21

Secondary palate (future roof of mouth) arises later from the medial aspects of the MXPs > ______

Answer 21

palatal shelves.

Question 22

Secondary palate (future roof of mouth) arises later from the medial aspects of the _____ > palatal shelves.

Answer 22

MXPs

Question 23

After immigration of cranial neural crest cells, growth & morphogenesis of the face is controlled by ongoing ________ interactions

Answer 23

epithelial-mesenchymal

Question 24

______ cells primarily determine facial form/shape

Answer 24

Cranial neural crest cells (CNCC)

Question 25

T/F: transplanted ectoderm retains FGF8/SHH pattern of expression from originating tissue.

Answer 25

True

Question 26

T/F: Secreted factors from the FEZ can direct outgrowth of the underlying CNCC and determines D-V pattern of the FNP, but precise shape depends upon pattern information inherent in the neural crest.

Answer 26

True

Question 27

A dynamic ____ does the following 3 things: 1. Support and direct outgrowth of the facial processes 2. Guides differentiation of CNC 3. Facilitating timely fusion of the facial processes

Answer 27

Ectoderm

Question 28

Fusion establishes the _______ and goes on to form the alveolus & lip proper

Answer 28

primary palate

Question 29

Fusion establishes the primary palate and goes on to form the _____ and _______

Answer 29

alveolus & lip proper

Question 30

Full fusion is required to ensure the _______ is continuous

Answer 30

alveolar bone

Question 31

Cleft lip +/-cleft primary palate is ____ most common birth defect (~1 in 700 births world-wide)

Answer 31

Third

Question 32

What week of development does the secondary palate form

Answer 32

10th week

Question 33

What week of development does the primary palate/lip form

Answer 33

7th week

Question 34

Ossification of the secondary palate (osteoblasts derived from CNCC) begins just _____ palatal development complete

Answer 34

before

Question 35

The _____ forms via the following processes: 1. Growth (either side of tongue) 2. Elevation & rotation 3. Medial growth & fusion at midline and with nasal septum

Answer 35

Secondary palate

Question 36

Cleft secondary palate can result from what 3 things?

Answer 36

1) poor growth of shelves, 2) failed elevation, or 3) failed fusion

Question 37

______ can provide a physical barrier to secondary palate closure

Answer 37

Macroglossia (enlarged tongue)

Question 38

_______ is also associated with failed palatal fusion (Pierre-Robin sequence)> Tongue forced backward and elevated

Answer 38

Small or retrognathic mandible

Question 39

T/F: Critical that tongue lowers to allow the shelves to rotate to a position above the tongue

Answer 39

True

Question 40

_______ first appears in the mandible and shortly thereafter in the midface and cranial base > Provides structural support for shaping the growing head > Precedes ossification

Answer 40

Craniofacial cartilage

Question 41

Cartilage of PA1 arises during 7th week (human) > forms template for the mandible.

Answer 41

(Meckel’s cartilage)

Question 42

Meckel's Cartilage of PA1 arises during ____ week (human) > forms template for the mandible.

Answer 42

7th

Question 43

Meckel's Cartilage of PA1 arises during 7th week (human) > forms template for the _____

Answer 43

mandible

Question 44

_____ portions of ear: •Derivatives of PA1 and PA2 •Intervening pharyngeal cleft •Pharyngeal pouch

Answer 44

•External and middle ear

Question 45

_____ portions of ear: •Arises from thickening of ectoderm (otic placode) dorsal to PA3 at level of hindbrain and subsequent invagination (otic pit)

Answer 45

Inner ear

Question 46

Inner and outer ear malformations often associated with _____ defects

Answer 46

mandibular