Oral & Nasal Cavity

Question 1

Describe the formation of Nasal Cavity

Answer 1

Medial and lateral prominences develop forming a nasal pit (ectoderm)
Nasal pit moves dorsally
Prominences merge to form Nasal sac (ectoderm) nasal plug (epithelial, will degenerate)

Question 2

Describe formation of Nasal cavity/ Oral Cavity

Answer 2

Nasal sac and stomadeum invaginate dorsally
Oronasal membrane degrades
Nasal and oral cavity join and result in
-Oronasal membrane ruptures
-Choanae- posterior to nasal aparatures 
-Primary Palate
Palate and nasal conchae forms

Question 3

How do sinuses form

Answer 3

From outgrowths of nasal cavity called diverticulations

Question 4

What 4 sinuses are there

Answer 4

Maxillary, frontal, ethmoid, sphenoid

Question 5

Nasal Histology

Answer 5

Pseudostratified columnar epithelium with cilia
Goblet cells rest on basement membrane
Vascular lamina proper (connective tissue) warms the air

Question 6

Paranasal Sinuses differnces

Answer 6

Thinner than nasal mucosa and fewer goblet cells

Question 7

Olfactory epithelium differences

Answer 7

Bipolar olfactory nerve cells
Formed from ectoderm
Attach to olfactory bulbs

Question 8

Primary Palate formation

Answer 8

Median and lateral processes fuse and form

Intermaxillary segment- comes from median palatine process forming primary palate

Question 9

Secondary Palate formation

Answer 9

Maxillary processes form lateral palatal processes and fuse anteriorly to posteriorly
3 outgrowths appear in oral cavity
-Nasal septum- grows downward and encounters the primary and secondary palates
-2 palatine shelves

Question 10

Completion of Palate

Answer 10

Lateral palatal shelves and nasal septum form ventrally (down)
Posterior part of primary meets secondary plate and fuse
Mandibular growth releases tongue

Question 11

Primary Plate forms

Answer 11

Incisive foramen and distal lateral incisors

Question 12

Secondary plate forms

Answer 12

Maxilla, palatine bones, soft palate, and uvulva