Embryology of the nasal and oral cavity

Question 1

What are nasal placodes?

Answer 1

They are local thickenings of surface ectoderm on either side of Frontal nasal prominence

Question 2

What are nasal pits?

Answer 2

Surrounded medial and lateral nasal prominence.

-The oronasal membrane separates pits from oral cavity at primitive choanae.

Question 3

What is the maxillary prominence?

Answer 3

Fuses with medial nasal prominences to form upper lips.

Question 4

What is the mandibular prominence?

Answer 4

Fuses to form lower lips and jaw

Question 5

What is the nasolacrimal groove?

Answer 5

Furrow between maxillary and lateral nasal prominences

• forms nasolacrimal duct and lacrimal sac
• oblique facial cleft- failure to fuse

Question 6

What is the primary palate?

Answer 6

its the intermaxillary segment- the fusion of medial nasal prominences to form philtrum of the lip and primary palate (Premaxillae), Which carries upper incisors and back to the incisive foramen

Question 7

What happens from failure of fusion and formation of the primary palate?

Answer 7

Cleft lip, cleft upper jaw, cleft between primary and secondary palatine.

Question 8

What is the secondary palate?

Answer 8

Forms from palatine shelves of maxillary prominence.

• Fuses with primary palate at incisive foramina and nasal septum.
• Cleft secondary and uvula is failure of fusion of the secondary palate