Deck 18: Development of Orofacial Complex

Question 1

The time span from fertilization through two weeks of gestation is referred to as the period of the ovum. The embryonic period of the fetus occurs from the third through the ninth week of gestation.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Answer 1

B
The period of the embryo, occurring from the third through the eighth weeks of gestation, immediately follows the period of the ovum. The period of the fetus takes place from the ninth through the 36th weeks of gestation.

Question 2

Formation of a median palatine cyst occurs during migration of the palatal shelves because a few epithelial cells remain embedded in connective tissue and fail to fuse.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Answer 2

D
A median palatine cyst may occur during fusion of the palatal shelves. The reason correctly describes the retention of epithelial cells within connective tissues. Such retained cells are referred to as epithelial rests. Conversely, migration is a term used to describe movement of tissues, such as development of the upper lip. Failure of labial tissues to migrate may result in a cleft lip. Note the subtle distinction between the mechanisms of fusion and migration.

Question 3

A unilateral cleft lip is the lack of connective tissue migration between one maxillary process and the fused medial nasal processes. A bilateral cleft lip is the lack of connective tissue migration between both maxillary processes and the fused medial nasal processes.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Answer 3

A
By the sixth week the two medial nasal processes should have fused together and, along with the maxillary processes, formed the upper lip. Note that the lateral nasal process takes no part in forming the upper lip. The medial nasal and maxillary processes begin to fuse at their lower end. The connection is known as the nasal fin.

Question 4

If the thyroid gland does not form normally, a red lump known as a lateral lingual swelling develops. This abnormal formation is located on the floor of the mouth.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 5

Migration refers to

A) Early tooth bud mesial drift
B) Deepening of the nasal pits
C) Increase in connective tissue of the upper lip
D) Fusion of the medial nasal process

Question 6

The embryonic heart is seen as a bulge because it develops in an extremely anterior position.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 7

A globulomaxillary cyst results from improper fusion of the maxillary and mandibular processes. This cyst lies between the maxillary lateral incisor and canine.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 8

Both the muscles of mastication and the muscles of facial expression are innervated by the fifth cranial nerve. The muscles of mastication arise from the first pharyngeal arch and the muscles of facial expression arise from the fifth cranial arch.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 9

The first and second pharyngeal arches are the largest because they are formed earlier in the developmental process.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 10

A 3-week-old embryo is approximately 4 mm from the top of the head to the tail area. The buccopharyngeal membrane begins to develop at this time.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false. the second is true.
D) Both statements are false.

Question 11

Each of the following is true of the buccopharyngeal membrane EXCEPT one. Which one is the EXCEPTION?

A) The buccopharyngeal membrane is the point where the foregut and stomodeum share a common wall.
B) The buccopharyngeal membrane forms the descending and sigmoid colon.
C) This membrane is found near the future site of both the palatine tonsils and the posterior portion of the tongue.
D) The buccal pharyngeal membrane breaks down at about $4 {~~1 / 2}$ weeks.

Question 12

By the end of the eleventh week the upper lip has formed because the two medial nasal processes have fused together.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 13

Which pharyngeal arch will degenerate after formation?

A) Third
B) Fourth
C) Fifth
D) Sixth
E) None

Question 14

The midgut forms all of the following EXCEPT one. Which one is the EXCEPTION?

A) Small intestine
B) Cecum
C) Ascending colon
D) Sigmoid colon
E) Descending colon

Question 15

The foramen cecum is the point where the thyroid gland begins to develop. It is a small depression near the eustachian tube.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 16

Landmarks that separate the pharyngeal arches are known as all of the following except the pharyngeal

A) Clefts
B) Grooves
C) Pouches
D) Openings

Question 17

A cyst can form during the fusion of the palate. If the cyst develops along the fusion line of the two palatal shelves, it is known as a globulomaxillary cyst.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 18

The buccopharyngeal membrane is significant to head and neck anatomy because when it breaks down at about 10 weeks, the connection between the oral cavity and the digestive tract is established.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct, but the reason is NOT correct.
D) The statement is NOT correct, but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 19

The thyroid gland originates from the

A) Foramen cecum
B) Anterior two-thirds of the tongue
C) Posterior third of the tongue
D) Midline of the inner surface of the pharyngeal arches
E) All of the above

Question 20

The hyoid arch is pharyngeal arch number

A) I
B) II
C) III
D) IV

Question 21

In a pregnant woman, which of the following are known to increase risk for having a baby with a cleft lip or palate (select all that apply)?

A) Smoking and other forms of tobacco use
B) Prescription medications
C) Environmental pollutants
D) Family history
E) Alcohol
F)Not of above

Question 22

The stomodeum forms the oral cavity and the oral pharynx.

Question 23

Six pharyngeal arches can be seen in a 3-week-old embryo.

Question 24

Rathke's pouch forms the posterior part of the pituitary gland.

Question 25

During formation of the upper lip, the lateral and medial nasal processes fuse.

Question 26

Which of the following are involved in formation of the tongue (select all that apply)?

A) Lateral lingual swellings
B) Tuberculum impar
C) Fifth pharyngeal arch
D) Copula
E) Frontal prominence

Question 27

The trigeminal nerve innervates the first pharyngeal arch.

Question 28

Development of a cleft palate occurs between the 7th and the 11th week. If it occurs early, only the soft palate or uvula will be affected.

A) Both statements are true.
B) The first statement is true; the second is false.
C) The first statement is false; the second is true.
D) Both statements are false.

Question 29

The hyoid bone arises from the second and third pharyngeal arches.

Question 30

Which ethnic group is most likely to have a combined cleft lip and palate?

A) Caucasians
B) Asians
C) African Americans
D) There is very little differentiation by ethnicity.

Question 31

The mandibular arch is divided into the maxillary and mandibular processes.