Lecture 33: Development of Head and Neck II Flashcards Preview

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Flashcards in Lecture 33: Development of Head and Neck II Deck (21):
1

What do the nasal placodes require for development of nose?

Pax6 and retinoids

2

What primordium of the nose is the source of retinoids that stimulate FGF-8 to stimulate proliferation of mesenchyme and nasomedial/lateral processes?

Nasal pits

3

From what is olfactory epithelium derived and what does it require?

Nasal pits; requires FGF-8

4

Name the 5 stages of tooth development

Dental lamina, Tooth bud, Cap stage, Bell stage, Dental sac

5

At what stage of tooth development do the enamel organ and dental papilla first appear at the same time?

Bell stage

6

What cells are associated with enamel?

Ameloblasts

7

What cells are associated with dentin?

odontoblasts

8

What molecule is necessary for tooth development to continue past the bud stage?

Pax9

9

Describe the action of BMP-4 during tooth development

Inhibits FGF-8, creates non-tooth forming spaces

10

What is the effect of high [Osr-2] with regard to tooth development?

Suppresses tooth-inducing activity of BMP-4

11

What is unique about the location of the Shh/FGF signaling during salivary gland development?

Occurs within the epithelium (rather than between epithelium and mesenchyme)

12

Cleft lip

Results from lack of fusion of nasomedial and maxillary processes

13

Cleft palate

Results from incomplete/absent fusion of palatal shelves

14

Holoprosencephaly

Defective formation of forebrain/prosencephalon; root cause is inability of prechordal plate and anterior endoderm to secrete Shh

15

Dentinogenesis imperfecta

Teeth appear blue-grey or amber brown and opalescent; can be non-syndromic or associated with osteogenesis imperfecta

16

Amelogenesis imperfecta

Affects development of enamel; result in abnormalities that affect amount/composition/structure of enamel

17

The facial nerve (VII) supplies muscles derived from which pharyngeal arch?

A. First
B. Second
C. Third
D. Fourth
E. Sixth

B. Second

18

Cleft lip results from lack of fusion of the:

A. Nasomedial and nasolateral processes
B. Nasomedial and maxillary processes
C. Nasolateral and maxillary processes
D. Nasolateral and mandibular processes
E. Nasomedial and mandibular processes

B. Nasomedial and maxillary processes

19

In cases of holoprosencephaly, defects of facial structures are typically secondary to defects in the:

A. Pharynx
B. Oral cavity
C. Forebrain
D. Eyes
E. Hindbrain

C. Forebrain

20

Meckel's cartilage is a prominent structure in early formation of the:

A. Upper jaw
B. Hard palate
C. Nasal septum
D. Soft palate
E. Lower jaw

E. lower jaw

21

An early induction in tooth development consists of ectoderm of the dental epithelium acting on underlying neural crest mesenchyme. What molecule is an important mediator of this inductive stimulus?

A. BMP-4
B. Tenascin
C. Hoxb-13
D. Msx-1
E. Syndecan

A. BMP-4