DEN 110 EXAM 3 QUESTIONS & ANSWERS
1. what is embryology the study of- Answers - prenatal development
2. what is the globular process (intermaxillary segment) formed from- Answers -
the lower border of the medial nasal process
3. what process does the zygote undergo after fertilization- Answers - mitosis
(cell division or cleavage)
4. what germ layers line the stomodeum and the foregut- Answers - the
stomodeum is lined by ectoderm and the foregut is lined by endoderm
5. how does the stomodeum form- Answers - the cephalic end (ectoderm) invaginated into a
depression and contact the endoderm of the foregut
6. what causes the bilaminar embryonic disc to have bilateral symmetry-
Answers - the primitive streak, which is a furrowed, rod-shaped thickening in the middle of the disc
resulting from increased proliferation of cells
7. why is the embryonic period considered the most critical period of prenatal
development- Answers - it is when the essential external and internal structures begin to form
8. what is the size of a fetus at 3 months- Answers - 61 mm
9. what is required for growth (increase in weight and size) to occur- Answers -
an increase in the number of cells, the size of cells, and the product of cells
10. what significant event occurs during the 4th week that establishes the axis of
the embryo- Answers - the disc undergoes embryonic folding, which places forming tissue types into their proper
positions and produces a tubular embryo
11. can permanent teeth be affected by tetracycline strain- Answers - yes, permanent
teeth may also be attected if the drug is given to a child during their development
12. what is ectodermal dysplasia- Answers - a condition resulting from abnormalities of the teeth, skin,
hair, nails, eyes, facial structure, and glands, often including partial or complete anodontia and development
disturbances
,13. what is the size of a fetus at 4 months- Answers - 116 mm
14. what divided the body and root/base of the tongue- Answers - the sulcus terminalis (v-
shaped row of circumvallate papillae)
15. what does ecto mean in relation to the ectoderm- Answers - outside
16. what are some characteristic of treacher collins syndrome- Answers - downward
slanting eyes, underdeveloped xygomatic bone, drooping lateral lower eyelids, hearing loss
17. when are clefts of the palate apparent- Answers - by 12 weeks
, 18. what do the migratory cells located between the epiblast and hypoblast
layers become- Answers - they become mesenchyme (an embryonic connective tissue)
19. what are the lateral palatine processes- Answers - ingrowths (palatal shelves) from each
maxillary process that invaginate the stomodeum
20. what are teratogenic effects- Answers - ettects caused by agents that can disrupt embryonic or fetal
develop- ment, leading to birth defects or malformations
21. what might be associated with pitting and intrinsic stain in permanent teeth
enamel (enamel dysplasia) in children- Answers - overuse of amoxicillin in children with
ear/respiratory infections
22. what are they 3 primary embryonic layers- Answers - ectoderm, mesoderm, and
endoderm
23. what two embryonic structures primarily contribute to early facial develop-
ment- Answers - the frontonasal (frontal) process and the 1st branchial arch
24. when is the lip complete during prenatal development- Answers - by the end of the
second month (7-8 weeks)
25. what is the treatment consideration for ankyloglossia if it does not adjust
over time- Answers - surgical cutting of the frenum is considered
26. what does the oropharyngeal membrane consist of- Answers - it consists of only
ectoderm exter- nally and endoderm internally, without any intermediate mesoderm
27. in what direction does palatal fusion usually occur- Answers - in an anterior to posterior
direction
28. what does endo mean in relation to the endoderm- Answers - inside
29. what major congenital malformation can occur due to disturbances in meio-
sis during fertilization in the preimplantation period- Answers - major congenital
malformations such as ectopic pregnancy and down syndrome
30. what causes tetracycline stain in childrens teeth- Answers - tetracycline antibiotic therapy of
1. what is embryology the study of- Answers - prenatal development
2. what is the globular process (intermaxillary segment) formed from- Answers -
the lower border of the medial nasal process
3. what process does the zygote undergo after fertilization- Answers - mitosis
(cell division or cleavage)
4. what germ layers line the stomodeum and the foregut- Answers - the
stomodeum is lined by ectoderm and the foregut is lined by endoderm
5. how does the stomodeum form- Answers - the cephalic end (ectoderm) invaginated into a
depression and contact the endoderm of the foregut
6. what causes the bilaminar embryonic disc to have bilateral symmetry-
Answers - the primitive streak, which is a furrowed, rod-shaped thickening in the middle of the disc
resulting from increased proliferation of cells
7. why is the embryonic period considered the most critical period of prenatal
development- Answers - it is when the essential external and internal structures begin to form
8. what is the size of a fetus at 3 months- Answers - 61 mm
9. what is required for growth (increase in weight and size) to occur- Answers -
an increase in the number of cells, the size of cells, and the product of cells
10. what significant event occurs during the 4th week that establishes the axis of
the embryo- Answers - the disc undergoes embryonic folding, which places forming tissue types into their proper
positions and produces a tubular embryo
11. can permanent teeth be affected by tetracycline strain- Answers - yes, permanent
teeth may also be attected if the drug is given to a child during their development
12. what is ectodermal dysplasia- Answers - a condition resulting from abnormalities of the teeth, skin,
hair, nails, eyes, facial structure, and glands, often including partial or complete anodontia and development
disturbances
,13. what is the size of a fetus at 4 months- Answers - 116 mm
14. what divided the body and root/base of the tongue- Answers - the sulcus terminalis (v-
shaped row of circumvallate papillae)
15. what does ecto mean in relation to the ectoderm- Answers - outside
16. what are some characteristic of treacher collins syndrome- Answers - downward
slanting eyes, underdeveloped xygomatic bone, drooping lateral lower eyelids, hearing loss
17. when are clefts of the palate apparent- Answers - by 12 weeks
, 18. what do the migratory cells located between the epiblast and hypoblast
layers become- Answers - they become mesenchyme (an embryonic connective tissue)
19. what are the lateral palatine processes- Answers - ingrowths (palatal shelves) from each
maxillary process that invaginate the stomodeum
20. what are teratogenic effects- Answers - ettects caused by agents that can disrupt embryonic or fetal
develop- ment, leading to birth defects or malformations
21. what might be associated with pitting and intrinsic stain in permanent teeth
enamel (enamel dysplasia) in children- Answers - overuse of amoxicillin in children with
ear/respiratory infections
22. what are they 3 primary embryonic layers- Answers - ectoderm, mesoderm, and
endoderm
23. what two embryonic structures primarily contribute to early facial develop-
ment- Answers - the frontonasal (frontal) process and the 1st branchial arch
24. when is the lip complete during prenatal development- Answers - by the end of the
second month (7-8 weeks)
25. what is the treatment consideration for ankyloglossia if it does not adjust
over time- Answers - surgical cutting of the frenum is considered
26. what does the oropharyngeal membrane consist of- Answers - it consists of only
ectoderm exter- nally and endoderm internally, without any intermediate mesoderm
27. in what direction does palatal fusion usually occur- Answers - in an anterior to posterior
direction
28. what does endo mean in relation to the endoderm- Answers - inside
29. what major congenital malformation can occur due to disturbances in meio-
sis during fertilization in the preimplantation period- Answers - major congenital
malformations such as ectopic pregnancy and down syndrome
30. what causes tetracycline stain in childrens teeth- Answers - tetracycline antibiotic therapy of
