Embryology

Question 1

Branchial arches:
Question 1 Select one:

a. are made up of ectoderm, mesoderm and endoderm.

b. all share a common blood supply.

c. each have their own nerve supply.

d. have derivatives for all 6 arches.

Answer 1

each have their own nerve supply

Question 2

Derivatives of the ectoderm include:
Question 2 Select one or more:

a. skin

b. enamel

c. skeleton

d. muscles

Answer 2

Enamel and skin

Question 3

During embryology the blastocyst:
Question 3 Select one:

a. is a solid ball of cells that forms from cleavage of the morula.

b. is a fluid filled ball of cells that forms after formation of the morula.

c. is a solid ball of cells that forms from cleavage of the zygote.

d. is a fluid filled ball of cells that forms after fertilisation of the zygote.

Answer 3

is a fluid filled ball of cells that forms after formation of the morula.

Question 4

Neural crest cells give rise to:
Question 4 Select one:

a. the neural tube and spinal cord of the body.

b. neuroectoderm and nerves in the head.

c. ectomesenchyme and connective tissue in the head.

d. somites and blood vessels in the head.

Answer 4

ectomesenchyme and connective tissue in the head

Question 5

Select the correct answer regarding the development of the tongue:
Question 5 Select one:

a. The tongue develops after the palate.

b. The tongue is innervated by the glossopharyngeal nerve and the trigeminal nerve.

c. The tongue develops before the stomodeum.

d. The tongue develops from bulges in the 1st branchial arch

Answer 5

The tongue is innervated by the glossopharyngeal nerve and the trigeminal nerve.

Question 6

This branchial arch does NOT give rise to any structures:
Question 6 Select one:

a. I.

b. II.

c. III.

d. IV.

e. V.

f. VI.

g. none of the above.

Answer 6

V.

Question 7

The branchial arches innervated by the glossopharyngeal nerve (cranial nerve IX) are:
Question 7 Select one:

a. IV.

b. none of the above.

c. VI.

d. III.

e. V.

f. II.

g. I.

Answer 7

III.

Question 8

The derivatives of these branchial arches are innervated by the trigeminal nerve (cranial nerve V):
Question 8 Select one:

a. III.

b. V.

c. IV.

d. II.

e. none of the above.

f. VI.

g. I.

Answer 8

I.

Question 9

The development of the face begins in:
Question 9 Select one:

a. week 4.

b. week 5.

c. week 2.

d. week 3.

Answer 9

Week 4

Question 10

The development of the secondary palate:
Question 10 Select one:

a. enables fusion with the nasal septum and upper lip.

b. forms from an extension of the primary palate.

c. takes place in week 4 of embryogenesis.

d. creates the barrier between the oral and nasal cavities.

Answer 10

creates the barrier between the oral and nasal cavities

Question 11

The face begins to form from which processes:
Question 11 Select one:

a.frontonasal.

b. maxillary.

c. mandibular.

d. nasal placodes

Answer 11

frontonasal

Question 12

The muscular derivatives of these branchial arches are the muscles of facial expression:
Question 12 Select one:

a. VI.

b. I.

c. IV.

d. III.

e. V.

f. II.

g. none of the above.

Answer 12

II.

Question 13

The philtrum forms:
Question 13 Select one:

a. from fusion of the maxillary and medial nasal processes.

b. the lateral of the upper lip.

c. at the midline of the face.

d. from fusion of the mandibular and maxillary processes

Answer 13

from fusion of the maxillary and medial nasal processes

Question 14

The three layers of the embryonic trilaminar disc are:
Question 14 Select one:

a.ectoderm, mesoderm and endoderm.

b. ectoderm, ectomesenchyme and endoderm.

c. ectoderm, mesenchyme and endoderm.

d. ectoderm, neuroectoderm and endoderm

Answer 14

ectoderm, mesoderm and endoderm

Question 15

Which branchial arches give rise to the mandible:
Question 15 Select one:

a. I.

b. II.

c. III.

d. IV.

e. V.

f. VI.

g. none of the above

Answer 15

I.

Question 16

Which branchial arches give rise to the palatine tonsils:
Question 16 Select one:

a. I.

b. II.

c. III.

d. IV.

e. V.

f. VI.

g. none of the above

Answer 16

none of the above

Question 17

Cleft palate is a developmental anomalie that results from:
Question 1 Select one:

a. the failure of fusion of the two medial nasal processes

b. the failure of fusion of the palatine shelves together and the nasal septum

c. the failure of fusion of the palatine shelves and the medial nasal processes

d. the failure of fusion of the two medial nasal processes and the maxillary processes

Answer 17

the failure of fusion of the palatine shelves together and the nasal septum

Question 19

Duing childhood development, at age 4, environmental factors such as too much fluoide, can disrupt the amelogenesis process for permanent teeth.
Question 2 Select one:

a. True

b. False

Answer 19

True

Question 20

Ameloblasts form conical projections called Tomes Processes during which of the following stages of amelogenesis:
Question 3 Select one:

a. protective

b. desmolytic

c. secretory

d. maturative

e. morphogenic

Answer 20

secretory

Question 21

Differentiation of ameloblasts from pre-ameloblasts takes place in which of the following stages of tooth development?
Question 4 Select one:

a. Bud stage

b. Cap stage

c. Bell stage

d. Initiation

Answer 21

Bell stage

Question 22

Enamel, gingiva and the skin are direct derivatives of the ectoderm.
Question 5 Select one:

a. false

b. true

Answer 22

true

Question 23

During amelogenesis which cellular layer of the enamel organ collapses to allow for space for the ameloblasts:
Question 6 Select one:

a. outer enamel epithelium

b. stratum intermedium

c. inner enamel epithelium

d.reduced enamel epithelium

e. stellate reticulum

Answer 23

stellate reticulum

Question 24

During fetal development, amelogenesis for all primary teeth is completed before birth:
Question 7 Select one:

a. False

b. True

Answer 24

True

Question 25

During odontogenesis, the dental sac gives rise to: Question 8 Select one: a. the supporting structures of the teeth b. the tooth pulp c. the roots of the teeth d. the crowns of the teeth

Answer 25

the supporting structures of the teeth

Question 26

Odontogenesis starts with the following cellular layers at its initiation stage: Question 10 Select one: a. ectomesenchyme and oral epithelium b. ectomesenchyme and mesoderm c. ectomesenchyme and the dental lamina d. ectomesenchyme and ectoderm

Answer 26

ectomesenchyme and oral epithelium

Question 27

Select the single best answer: Question 12 Select one: a. The stratum intemedium plays a key role in dentinogenesis providing nutients to the odontoblasts b. The stellate reticulum plays a key role in amelogenesis paiing with the inner enamel epithelium and the ameloblasts c. The stratum intemedium plays a key role in amelogenesis by differentiating into preameloblasts and then ameloblasts d. The stellate reticulum plays a key role in amelogenesis by providing nutients to the ameloblasts

Answer 27

The stellate reticulum plays a key role in amelogenesis by providing nutients to the ameloblasts

Question 28

9. Select the single best answer: Question 13 Select one: a. All oral tissues originate from the ectoderm and the mesoderm b. All oral tissues originate from the ectoderm and the endoderm c. All oral tissues originate from the ectoderm and the ectomesenchyme (neural crest cells) d. All oral tissues originate directly from the ectoderm

Answer 28

All oral tissues originate from the ectoderm and the ectomesenchyme (neural crest cells)

Question 29

The 2 stages of amelogenesis and dentinogenesis can be described as: Question 14 Select one: a. matrix formation and mineralisation of the hard tooth tissues b. secretory stage and the mineralisation c. secretion of the matrix followed by maturation of the matrix d. All of the above e. matrix secretion and calcification of the matrix

Answer 29

All of the above

Question 30

The origin of the dento-gingival junction is the: Question 15 Select one: a. Vestibular lamina b. Reduced enamel epithelium c. Dental lamina d. Dental follicle

Answer 30

Reduced enamel epithelium

Question 31

The development of the face begins in:

Answer 31

Week 4

Question 32

The lifecycle of the ameloblast is: Question 18 Select one: a. limited to the time the tooth erupts b. limited to the completion of the bell stage c. limited to the life of the tooth d. limited to the time crown formation is complete

Answer 32

limited to the time the tooth erupts

Question 33

The long junctional epithelium originates from: Question 19 Select one: a. Ectoderm → ectomesenchyme → inner enamel epithelium b. Ectoderm → oral epithelium → outer enamel epithelium c. Ectoderm → ectomesenchyme → outer enamel epithelium d. Ectoderm → oral epithelium → inner enamel epithelium

Answer 33

Ectoderm → oral epithelium → outer enamel epithelium

Question 34

The morphology of the tooth crown starts to be determined at which stage of development: Question 20 Select one: a. initiation b. early bell stage c. cap stage d. bud stage e. late bell stage

Answer 34

Early bell stage

Question 35

Which two cellular layers are present at the dental lamina stage of tooth development? Question 27 Select one: a. ectomesenchyme and ectoderm b. oral epithelium and mesoderm c. oral epithelium and ectomesenchyme d. ectoderm and mesoderm

Answer 35

oral epithelium and ectomesenchyme

Question 36

Which branchial arches do the muscles of mastication derive from? Question 24 Select one: a. IV b. III c. VI d. II e. V f. I

Answer 36

I

Question 37

The morphology of the tooth crown starts at which stage of the development

Answer 37

Early bell stage

Question 39

Which of the following is not part of the enamel organ . Stellate reticulum . Odontoblasts . Inner enamel epithelium . Stratum intermedium

Answer 39

Odontoblasts

Question 40

The origin of the dentino-gingival junction is the:

Answer 40

Reduced enamel epithelium