Development of the Face, Jaws and Mouth

Question 1

what is a placode?

Answer 1

Area of ectoderm found at the location of the developing special sense organs on the embryo.

Question 2

what is a nasal placode?

Answer 2

Placodes that develop into olfactory organ for the sensation of smell located in the mature nose.

Question 3

name this facial swelling

Answer 3

fronto-nasal prominence

Question 4

name this facial swelling

Answer 4

1st arch

Question 5

Answer 5

stomatodeum

Question 6

name this facial swelling

Answer 6

maxillary process

Question 7

Answer 7

mandibular process

Question 8

what is pseudofusion of a pharyngeal groove? example?

Answer 8

not true fusion
Groove is eliminated through tissues in the groove proliferating

Between medial nasal prominence

Question 9

example pseudofusion

Question 10

what is true fusion between pharyngeal grooves? example?

Answer 10

True separate processes growing towards each other

Between medial nasal prominence and maxillary process

Question 11

what happens in the 4th week of face development?

Answer 11

Stomodeum bound by the 5 processes (fronto-nasal prominence, mandibular and maxillary processes)

Nasal placodes develop into nasal pits

Question 12

what happens in the 5th week of face development?

Answer 12

Nasal pit surrounded by lateral and medial nasal prominences formed by differentiation

Question 13

what happens in the 6th and 7th week of face development?

Answer 13

Medial and lateral nasal prominences fuse together and fuse with maxillary processes

Question 14

what process is blue?

Answer 14

frontonasal process

Question 15

what process is yellow?

Answer 15

medial nasal process

Question 16

what process is pink?

Answer 16

lateral nasal process

Question 17

what process is light green?

Answer 17

maxillary process

Question 18

what process is dark green?

Answer 18

mandibular process

Question 19

what does the frontonasal process form?

Answer 19

forehead and bridge of nose

Question 20

what does the medial nasal process form?

Answer 20

philtrum of the lip
crest and tip of nose

Question 21

what does the lateral nasal processes form?

Answer 21

alae of nose

Question 22

what does the maxillary process form?

Answer 22

cheeks
lateral upper lip

Question 23

what does the mandibular process form?

Answer 23

lower lip

Question 24

when does ossification of the mandible occur?

Answer 24

6th-7th week

Question 25

when does ossification of the maxilla occur?

Answer 25

week 8

Question 26

when does ossification of the primary palate occur?

Answer 26

week 8

Question 27

when does ossification of the nasal capsule occur?

Answer 27

week 8

Question 28

what is intramembranous ossification?

Answer 28

Mesenchymal cells differentiate into osteoblasts which deposit osteoid forming bone. Osteoblasts also differentiate into osteocytes to maintain bone matrix

Question 29

what is endochondral ossification?

Answer 29

Bone forming from cartilage

Question 30

what controls pattern formation?

Answer 30

retonoic acid and growth factors

Question 31

what growth factors control pattern formation?

Answer 31

BMP, FGF, Shh, Wnt and endothelins Control cell proliferation, survival and apoptosis

Question 32

cartilage is a strong, flexible and semi-rigid supporting tissue made by what?

Answer 32

chondroblasts and chondrocytes

Question 33

functions of cartilage 3

Answer 33

supporting framework of some organs articulating surface of bone so they don’t rub together and cause damage template for growth and development where they are gradually replaced by bone

Question 34

- The surface of most cartilage is ? -> dense irregular connective tissue

Answer 34

perichondrium

Question 35

what are the two growth mechanisms for cartilage?

Answer 35

interstitial appositional

Question 36

what is interstitial growth mechanism of cartilage?

Answer 36

chondrocytes make matrix inside the existing cartilage

Question 37

what is appositional growth mechanism of cartilage?

Answer 37

chondroblasts from the perichondrium add new surface layers to the pre-existing matrix

Question 38

what is the main cartilage of the 1st pharyngeal arch?

Answer 38

meckel's cartilage

Question 39

meckels cartilage is developed from what type of cells?

Answer 39

crest cells

Question 40

what growth factor controls the growth of meckel's cartilage?

Answer 40

CNN2 - connective tissue growth factor

Question 41

what does a lack in the connective tissue growth factor CCN2 result in?

Answer 41

cleft palates of mice

Question 42

formation of the mandible first forms by what kind of ossification? where?

Answer 42

intramembranous ossification -> primary site of ossification is between the incisive and mental nerve

Question 43

what growth factor is involved in formation of the mandible?

Answer 43

Vascular endothelial growth factor VEGF

Question 44

development of the mandible During final development ossification changes to what kind of ossification? where?

Answer 44

endochondral ossification at secondary cartilage sites

Question 45

formation of the mandible week ? Mandible first appears as a band of ?? tissue, located where the ?? branches to ? and ?? Formation of bone spreads rapidly ? below the ?? and on the ? side of the ? ? ossification

Answer 45

7 dense fibrocellular mandibular IAN mental incisive nerve backwards mental nerve lateral IAN intramembranous

Question 46

formation of the mandible week ? Ossification moves away from the ?? to form the ???? following the line of the ?? Cartilage then ? or ? parts of the bones of the ??

Answer 46

10 meckel's cartilage ramus of the mandible mandibular nerve dissappears forms inner ear

Question 47

in formation of the mandible, what happens just before birth?

Answer 47

secondary mandibular cartilages formed

Question 48

how do secondary mandibular cartilages differ from primary cartilage?

Answer 48

in secondary cells are larger and have less intracellular matrix

Question 49

name the 3 secondary mandibular cartilages

Answer 49

condylar cartilage coronoid cartilage synphyseal cartilage

Question 50

what is the most important secondary mandibular cartilage?

Answer 50

condylar cartilage

Question 51

when does condylar cartilage appear?

Answer 51

weeks 10-12

Question 52

where is condylar cartilage located?

Answer 52

majority of the mandible

Question 53

which secondary mandibular cartilage is quickly turned into bone? what type of ossification?

Answer 53

condylar cartilage endochondral ossification

Question 54

when does condylar cartilage dissappear?

Answer 54

20yrs of age

Question 55

when does coronoid cartilage appear?

Answer 55

14-16 weeks

Question 56

when does coronoid cartilage dissapear?

Answer 56

before birth

Question 57

where does symphyseal cartilage appear?

Answer 57

in the connective tissue between the two ends of Meckel's cartilage

Question 58

when does synphyseal cartilage appear?

Answer 58

week 16

Question 59

when does symphyseal cartilage dissapear?

Answer 59

1st year after birth

Question 60

what is osteogenesis?

Answer 60

process of laying down new bone material by osteoblasts

Question 61

how does osteogenesis work in a developing foetus?

Answer 61

Osteoclasts absorb cartilage as ossification occurs in developing foetus

Question 62

name this secondary mandibular cartilage

Answer 62

coronoid cartilage

Question 63

Answer 63

condylar cartilage

Question 64

Answer 64

symphyseal cartilage

Question 65

formation of the mandible, understand