1 Formation of Face & Oral Cavity

Question 1

Which of the four named lingual swellings become the anterior 2/3 of the tongue?

Answer 1

Tuberculum impar and 2 lateral (R/L) lingual swellings

Question 2

4 week embryo. Maxillary processes give rise to palatine folds. What arises from inner part of median nasal process?

Answer 2

Primary palate

Question 3

The stomodeum, in the third embryonic week, is bounded below by the cardiac plate and above by which of the following? A primary palate B. palatine folds C. frontal prominence D. maxillary prominence

Answer 3

C. Frontal prominence. Yes, it’s the upper boundary of the stomodeum. The nasal pits appear within the prominence during the fourth embryonic week.

Question 4

Which of the following events occur during the fourth embryonic week? (More than one correct answer). A. Rupture of buccopharyngeal membrane B. Appearance of tongue C. Appearance of branchial arches D. Disappearance of branchial arches

Answer 4

A. Yes, it ruptures allowing direct communication of the stomodeum with the pharynx. B. Yes, it begins formation as four lingual swellings that evolve into one structure, the tongue. C. Yes, the four distinct paired arches appear and play a key role in the formation of the face, mouth, and neck. D. Yes, the first arch becomes the facial processes that become parts of the face. The rest of the arches are covered over by the operculum, an extension of the second arch.

Question 5

The epithelial lining of which of the following structures fuse with one another during the formation of the hard and soft palates (secondary palate)? (More than one answer.) A. mandibular processes B. Primary palate C. Nasal septum D. Palatine folds

Answer 5

A. No, these processes do not enter into the formation of the secondary palate. B. Yes, its epithelial lining fuses with that of the palatine folds. C. Yes, its epithelium fuses with that of the palatine folds. D. Yes, the epithelia of the R and L palatine folds fuse with each other, and with that of the primary palate and of the nasal septum.

Question 6

The primary palate arises from which of the following embryonic structures? A. frontal prominence B. maxillary process C. median nasal process D. lateral nasal process

Answer 6

C. Median nasal process. The outer surface of the median nasal process becomes the midline of the nose and philtrum, and its inner surface becomes the primary palate, that eventually becomes the anterior part of the hard palate.

Question 7

T/F: The palatine folds are outgrowths of the primary palate?

Answer 7

F: They originate from the medial surfaces of the maxillary processes.

Question 8

Name the facial process that gives rise to the palatine fold.

Answer 8

The palatine folds arise from the medial side of the maxillary processes.

Question 9

The tongue begins forming in which of the following embryonic weeks? A. third B. fourth C. fifth D. sixth

Answer 9

B. Fourth; it appears and grows to fill the stomodeum in the fourth embryonic week.

Question 10

The tongue originates from how many embryonic swellings?

Answer 10

D. Four; the four swellings arise along the ventral surfaces of the first four branchial arches.

Question 11

Which of the following four lingual swellings becomes the root or posterior third of the tongue? A. R lateral lingual swelling B. L lateral lingual swelling C. Tuberculum impar D. copula

Answer 11

D. Copula; the copula becomes the root or posterior third of the tongue. The copula is also called the hypobranchial eminence.

Question 12

The palatine folds or shelves arise from which of the following facial processes? A. Median nasal process B. Lateral nasal process C. Maxillary processes D. mandibular processes

Answer 12

C. Maxillary processes, the palatine folds evolve from the stomodeal or medial sides of the maxillary processes.

Question 13

The embryonic swelling called tuberculum impar enters into the formation of which of the following structures? A. Primary palate B. Secondary palate C. Tongue D. Pituitary gland

Answer 13

C. Tongue; the tuberculum impar (along with the two lateral lingual swellings) enters into the formation of the anterior 2/3 of the tongue.

Question 14

T/F: The nasal septum arises from the roof of the stomodeum.

Answer 14

False. The septum arises from the midline of the primary palate, not the stomodeal roof. It fuses with palatine processes during the formation of the secondary palate.

Question 15

The stomodeum, in the third embryonic week, is separated from the foregut (future pharynx) by which of the following structures? A. Tongue B. Rathke’s pouch C. Buccopharyngeal membrane D. Fauces

Answer 15

C. Buccopharyngeal membrane. It is composed of two epithelial layers. It ruptures or breaks-up during the fourth embryonic week. Another name for the membrane is: “oropharyngeal membrane.”

Question 16

T/F: The stomodeum will develop into the oral and nasal cavities?

Answer 16

T: The stomodeum, a single cavity, is partitioned by the secondary palate into oral and nasal cavities.

Question 17

Answer 17

1. Tongue
2. Palatine folds

Question 18

Answer 18

1. Primary palate
2. Nasal septum
3. Palatine fold (vertical position)

Question 19

Answer 19

1. Nasal septum.
2. Palatine fold (vertical position)
3. Tongue

Question 20

Answer 20

1. Nasal septum
2. Palatine fold (horizontal position)
3. Tongue

Question 21

Identify.

When does third structure firs tappear in IU?

Answer 21

1. Nasal septum.
2. Palatine folds (epithelial fusion with other fold and nasal septum)
3. Appears in 4th embryonic week from the merger of 4 lingual swellings.

Question 22

Answer 22

1. Oral cavity
2. Nasal cavity

Separated by palatal union.

Question 23

Answer 23

A.Primary palate
B.Nasal septum
C.Palatine folds

Question 24

Answer 24

A.Nasal septum
B.Palatine folds

Question 25

Answer 25

UL: vetical palatine

UR: horizontal palatine

LL: fuse stage

LR: Merged stage

Question 26

Answer 26

Right red dot: the maxillary facial process. The palatine fold arises from the medial (stomodeal) side of the process. The two palatine folds enter into the formation of the hard and soft palate areas (secondary palate).

Question 27

Answer 27

The palatine folds arise from the medial side of the maxillary processes.

Question 28

Answer 28

Purple: tuberculum impar

Yellow: Lateral lingual swellings

Blue: copula

Black arrow: mandibular process