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)
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1
Q

What do the nasal placodes require for development of nose?

A

Pax6 and retinoids

2
Q

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

A

Nasal pits

3
Q

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

A

Nasal pits; requires FGF-8

4
Q

Name the 5 stages of tooth development

A

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

5
Q

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

A

Bell stage

6
Q

What cells are associated with enamel?

A

Ameloblasts

7
Q

What cells are associated with dentin?

A

odontoblasts

8
Q

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

A

Pax9

9
Q

Describe the action of BMP-4 during tooth development

A

Inhibits FGF-8, creates non-tooth forming spaces

10
Q

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

A

Suppresses tooth-inducing activity of BMP-4

11
Q

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

A

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

12
Q

Cleft lip

A

Results from lack of fusion of nasomedial and maxillary processes

13
Q

Cleft palate

A

Results from incomplete/absent fusion of palatal shelves

14
Q

Holoprosencephaly

A

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

15
Q

Dentinogenesis imperfecta

A

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

16
Q

Amelogenesis imperfecta

A

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

17
Q

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

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

B. Second

18
Q

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
A

B. Nasomedial and maxillary processes

19
Q

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
A

C. Forebrain

20
Q

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
A

E. lower jaw

21
Q

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

A. BMP-4