Week 1 - Intro to Oral Histopathology of Oral Tissues

Question 1

What are the 3 stages of human development?

Answer 1

Proliferation period (0-3 weeks)
Embryonic period (3-8 weeks)
Fetal development period (9 weeks to term)

Question 2

What is fertilized during the proliferation period and what does it yield?

Answer 2

Fertilization of ovum yields zygote

Question 3

What does the mitotic cleavage of zygote form?

Answer 3

Blastomeres

Question 4

> 32 blastomeres is called ______

Answer 4

morula

Question 5

The 64 cell stage morula develops an internal blastocystic cavity referred to as ______

Answer 5

blastocyst

Question 6

When the blastocyst develops an inner cell mass at days 6-7, what is this referred to?

Answer 6

Embryoblast

Question 7

When does implantation of the embryoblast in the uterine wall begin and complete?

Answer 7

Day 4; Day 10

Question 8

What does the inner cell mass of the embryoblast transition into?

Answer 8

The bilaminar embryonic disc (Two layers)

Question 9

What do the outer cell masses become?

Answer 9

Cytotrophoblast and syntrophoblast layers which are precursor to the placenta

Question 10

What are the layers of the bilaminar embryonic disc?

Answer 10

Epiblast layer
Hypoblast later

Question 11

What makes up the epiblast layer?

Answer 11

Ectoderm
Mesoderm

Question 12

What makes up the hypoblast layer?

Answer 12

Endoderm

Question 13

What structures are associated with the bilaminar embryonic disc?

Answer 13

Epiblast layer
Hypoblast layer
Amniotic cavity
Blastocyst cavity
Syntrophoblasts
cytotrophoblasts

Question 14

The enlargement of the amntiotic cavity and migration of cells out of the hypoblast form?

Answer 14

Heuser’s membrane

Question 15

What does the Heuser’s membrane form?

Answer 15

Internal lining of the blastocyst cavity - now called the yolk sac

Question 16

What are the three cell layers of the proliferation period?

Answer 16

Epiblast
Embryonic mesoderm
Hypoblast

Question 17

What are embryonic cavities of the proliferation period?

Answer 17

Amniotic
Yolk sac
Chorionic

Question 18

During the 3rd week of development, the bilaminar embryonic disc is characterized by formation of the:

Answer 18

Primitive streak
Notochord
Neural tube

Question 19

During the 3rd week of development, the bilaminar embryonic disc is characterized by formation of what three distinct embryonic germ layers?

Answer 19

Ectoderm (formerly the epiblast layer)
Mesoderm
Endoderm (formerly the hypoblast layer)

Question 20

What is a primitive streak? and what is visible during the time it is being formed?

Answer 20

Cells from the epiblast invaginating in forming the 3rd layer (mesoderm)

Pit
Node
Groove

Question 21

Describe the steps of how the notochord is created

Answer 21

Primitive node -> notochordal process -> notochord

Question 22

What invaginates within the primitive node?

Answer 22

Pre-notochordal cells

Question 23

Cells invaginate until they reach the?

Answer 23

Prechordal plate “road block”

Question 24

When the cells detach themselves from the ectodermal layer to line within the mesoderm, it forms the?

Answer 24

Notochord

Question 25

What does the notochord function as?

Answer 25

A primitive skeletal sipport of the embryo around which the axial skeleton later forms

Question 26

What does the notochord induce formation of?

Answer 26

Somites, the precursors of the vertebral column, ribs, associated back muscles and overlying dermis

Question 27

What cells is the notochord made from and what is it derived from?

Answer 27

Ectodermal cells; primitive node

Question 28

What does the notochord establish?

Answer 28

Symmetry and polarity of development

Question 29

What does the notochord induce?

Answer 29

Somites

Question 30

What two parts make up the lateral plate mesoderm?

Answer 30

Parietal Visceral

Question 31

What does the paraxial mesoderm form?

Answer 31

Somites

Question 32

What does the intermediate mesoderm form?

Answer 32

Urogenital system

Question 33

What does the parietal mesoderm form?

Answer 33

MEsothelial (serous) membranes that cover the perutoneal, pleural and pericardial cavities

Question 34

What does the visceral mesoderm form?

Answer 34

The thin serous membranes that cover individual organs, stomach, pancreas, spleen

Question 34

What are derivatives of ectoderm?

Answer 34

Epidermis, hair and nails Epithelium of the oral and nasal cavities and paranasal sinuses Salivary and endocrine glands Nervous system Tooth enamel

Question 34

What are derivatives of endoderm?

Answer 34

GI tract epithelium and associated glands

Question 35

What are neural tube related developmental defects?

Answer 35

Spina bifida Meningocele Meningomyelocele Meningoencephalocele Anencephaly

Question 36

What is a spina bifida?

Answer 36

Folic acid deficiency

Question 37

What is meningocele?

Answer 37

Extrusion of dura and arachnoid mater

Question 38

What is meningomyelocele

Answer 38

Extrusion of neural tissue plus all three meninges

Question 39

What is meningoencephalocele?

Answer 39

Extrusion of a ventricular cistern plus neural tissue

Question 40

What is anencephaly?

Answer 40

Fetal defect characterized by lack of development of the cranium and brain

Question 41

What are examples of minor neural tube defects?

Answer 41

Spina bifida Meningocele

Question 42

What are severe neural tube defects?

Answer 42

Meningomyelocele Meningohydroencephalocele

Question 43

What are fatal defects of the neural tube?

Answer 43

Anencephaly

Question 44

What are different names for neural crest cells?

Answer 44

Ectomesencyme Neuroectoderm

Question 45

What are different names for neural crest cells?

Answer 45

Ectomesenchyme Neuroectoderm

Question 46

What does the 1st branchial groove develop into?

Answer 46

External auditory canal

Question 47

What does the 1st branchial pouch develop into?

Answer 47

Eustachian tube

Question 48

What does the 2nd branchial pouch develop into?

Answer 48

Palatine tonsils

Question 49

What does the 3rd branchial pouch develop into?

Answer 49

Inferior parathyroids/thymus

Question 50

What does the 4th branchial pouch develop into?

Answer 50

Superior parathyroids/ultimobranchial body

Question 51

What are processes of the face?

Answer 51

mandibular process maxillary process lateral nasal process median nasal process

Question 52

When does development of the face and oral cavity occur?

Answer 52

Fetal development period - 9 weeks to term

Question 53

Where is the development of the palate?

Answer 53

Hard palate and closes posteriorly

Question 54

What results in a cleft lip?

Answer 54

Defective fusion of the medial nasal process with the maxillary process

Question 55

When do the medial nasal process with the maxillary process fuse?

Answer 55

5-6 weeks of gestation

Question 56

When does fusion of the palatine shelves begin and complete?

Answer 56

During 8th week of gestation and completed by the 12th week

Question 57

Name the percents of frequency of combined cleft lip/palate and isolated cleft lip and palate

Answer 57

45% combined 30% isolated cleft palate 25% isolated cleft lip

Question 58

What is the frequency of cleft lip/palate among populations?

Answer 58

1 in 500 chinese, japanese, native american 1 in 700 caucasian 1 in 500 afro-american

Question 59

How prevalent is cleft palate?

Answer 59

1 in 2,500 births

Question 60

If one child is born with cleft lip, there is a _____ change of a second child exhibiting the same

Answer 60

40%

Question 61

What teratogens are involved in congenital malformations

Answer 61

Drugs- Ethanol Tetracyclcine Dilantin Lithium Methotrexate Warfarin Thalidomide Androgens Progesterone Retinoic Acid Chemicals- Methylmercury Polychlorinated biphenyls Radiation- high levels of ionizing radiation

Question 62

Where does the nasopalatine duct cyst develop at?

Answer 62

Line of fusion between palatine shelves and primary plate

Question 63

When does the cervical sinus remain past and doing so what can it cause?

Answer 63

Remains past 7th week; can cause lateral cervical cyst aka branchial cleft cyst aka branchial fistula

Question 64

What does the branchial arch #1 create?

Answer 64

Anterior 2/3 of the tongue

Question 65

What does the branchial arch #2 create?

Answer 65

Overgrown by the hypobranchial eminence

Question 66

What does the branchial arch #3 create?

Answer 66

posterior 1/3 of the tongue

Question 67

What does the branchial arch #4 create?

Answer 67

Minor contributions

Question 68

What cranial nerve and tongue structure is related to arch #1?

Answer 68

Trigeminal (C-V); sensory to the anterior 2/3

Question 69

What cranial nerve and tongue structure is related to arch #2?

Answer 69

Facial (C-VII); taste to anterior 2/3

Question 70

What cranial nerve and tongue structure is related to arch #3?

Answer 70

Glossopharyngeal (C-IX); sensory to the posterior 1/3

Question 71

What cranial nerve and tongue structure is related to arch #4?

Answer 71

Vegas (C-X); sensory to the extreme posterior 1/3 via the superior laryngela branch

Question 72

What cranial nerve and tongue structure is related to arch #6?

Answer 72

Hypoglossal (C-XII); motor to all tongue muscles

Question 73

What is median rhomboid glossitis a result of?

Answer 73

Fungal infection

Question 74

What is a failure of thyroglossal duct to involute?

Answer 74

Thyroglossal duct cyst

Question 75

Where is the thyroglossal duct cyst located?

Answer 75

Midline of neck

Question 76

What part of the face does the 1st arch make?

Answer 76

Mandible, maleus, incus

Question 77

What part of the face does the 2nd arch make?

Answer 77

Stapes, stylodi process, stylohyoid ligament, lesser horn of hyoid

Question 78

What part of the face does the 3rd arch make?

Answer 78

Greater horn of hyoid

Question 79

What part of the face does the 4th arch make?

Answer 79

thyroid cartilage

Question 80

How many auricular hilocks form the ear?

Answer 80

6