Palate Formation & Tongue Formation

Question 1

When does primary palate formation begin?

Answer 1

5 weeks

Question 2

How is the primary palate formed?

Answer 2

The fusion of the medial nasal processes to give rise to the intermaxillary segment which gives rise to the primary palate.

Question 3

What is the origin of the primary palate?

Answer 3

intermaxillary segment

Question 4

What does the primary palate give rise to?

Answer 4

pre-maxilla; which includes the incisors and can include the canines and nasopalatine nerve.

Question 5

What is the purpose of the primary palate?

Answer 5

To work to separate the oral and nasal cavities.

Question 6

When does secondary palate formation begin?

Answer 6

7th to 8th week

Question 7

What will the formation of the secondary palate create?

Answer 7

Complete separation between the nasal and oral cavities.

Question 8

What does embryology explain?

Answer 8

Why things are oriented in such strange ways.

Question 9

How is the nasal septum formed?

Answer 9

It develops downward from the fontonasal process at the midline.

Question 10

What arises from the maxillary process that is associated with the formation of the secondary palate?

Answer 10

2 palatine shelves

Question 11

What occurs after the seventh week so that the formation of the secondary palate can continue?

Answer 11

The tongue muscles begin to function and the tongue withdraws (moves anteriorly and inferiorly) to avoid becoming an obstacle during the formation of the secondary palate.

Question 12

How does the secondary palate form?

Answer 12

The 2 palatine shelves elevate and fuse to each other superior to the tongue.

Question 13

What does the secondary palate give rise to?

Answer 13

The posterior 2/3 of the hard palate which contains posterior teeth and sometimes the canines.

Question 14

How is the final palate formed?

Answer 14

The 2 palatine shelves elevate and fuse together and also fuse with the primary palate.

Question 15

What has to occur in order for fusion to occur?

Answer 15

Movement

Question 16

What influences movement?

Answer 16

Mucopolysaccharides in the Mesenchyme

Contractile fibroblasts

Question 17

What occurs when mucopolysaccharides are put into mesenchyme?

Answer 17

The sugar (mucopolysaccharide) draws water to the tissue making it swell which causes movement.

Question 18

What type of cells are contractile fibroblasts?

Answer 18

Connective tissue cells

Question 19

What tissue has to be touching for fusion to occur?

Answer 19

Mesenchyme has to be touching mesenchyme to fuse, this is why stitches are necessary.

Question 20

Proper fusion of the primary and secondary palate creates what?

Answer 20

Separation between the oral and nasal cavities.

Question 21

What are the 2 palatine shelves covered with as they are developing?

Answer 21

Epithelium

Question 22

True or False; epithelium can act a barrier when fusion occurs.

Answer 22

True; we need aptosis to occur so that mesenchyme can fuse with other mesenchyme tissues.

Question 23

When does tongue formation occur?

Answer 23

Starts at 4 weeks.

Question 24

What two structures are associated with the anterior 2/3 of tongue formation?

Answer 24

Tuberculum impar

Lateral Lingual Swellings

Question 25

Where does tuberculum impar arise from?

Answer 25

Arises at the midline from the 1st branchial arch.

Question 26

Where do the lingual swelling form?

Answer 26

They form laterally from the first arch.

Question 27

What do the tuberculum impar and the lateral lingual swellings give rise to?

Answer 27

Mucosa for the anterior 2/3 of the tongue.

Question 28

What arch is associated with the formation of the body of the tongue?

Answer 28

1st branchial arch.

Question 29

What arch is associated with the formation of the base of the tongue?

Answer 29

3rd branchial arch

Question 30

What process gives rise to the root or base of the tongue?

Answer 30

Hypobranchial eminence.

Question 31

True or False; the hypobranchial eminence also gives rise to the mucosa for the posterior 1/3 of the tongue which supplies general and taste sensations?

Answer 31

true

Question 32

Where do the muscles of the tongue aries from?

Answer 32

Occipital somites.

Question 33

What does the origin of the muscles of the tongue tell us about its innervation.

Answer 33

This explains why cranial nerve 12 supplies the motor innervation of the tongue because the muscles orginate from the occipital area.

Question 34

How do you explain why the taste sensation of the anterior 2/3 of the tongue comes from cranial nerve VII?

Answer 34

Chorda typmani runs in route with the lingual nerve from the 2nd arch which is innervated by cranial nerve VII/