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Histopath > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

what are the three stages of human development

A

-proliferation period
-embryonic period
-fetal development period

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2
Q

when does the proliferation period take place

A

0-3 weeks

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3
Q

when does the embryonic period take place

A

3-8 weeks

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4
Q

when does the fetal development period take place

A

9 weeks to term

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5
Q

what occurs during the proliferation period

A

-fertilization of ovum yields zygote
-mitotic cleavage of zygote forms blastomeres
-> or = to 32 blastomeres is called a morula
-64 cell stage called blastocyst
-blastocyst then developes inner cell mass and is called embryoblast
-embryoblast implants in uterine wall

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6
Q

fertilization of the ovum yields the

A

zygote

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7
Q

mitotic cleavage of the zygote forms the

A

blastomeres

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8
Q

more or equal to 32 blastomeres forms what

A

morula

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9
Q

the morula then develops into

A

blastocyst

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10
Q

at 64 cells it is called

A

blastocyst

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11
Q

why is a blastocyst called a blastocyst

A

morula develops an internal blastocystic cavity

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12
Q

what does the blastocyst become

A

embryoblast

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13
Q

what does the blastocyst develop to become the embryoblast

A

inner cell mass

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14
Q

when is the inner cell mass formed

A

days 6-7

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15
Q

Implantation of the embryoblast in the uterine wall begins and finishes when

A

begins at day 4 and is complete at day 10

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16
Q

The inner cell mass of the embryoblast transitions into what

A

bilaminar embryonic disc

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17
Q

what does the outer cell mass become

A

cytotrophoblast and syntrophoblast

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18
Q

what are the cytotrophoblast and syntrophoblast layers the precursor for

A

the placenta

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19
Q

what are the layers of the bilaminar embryonic disc

A

epiblast and hypoblast

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20
Q

what makes up the epiblast layer

A

ectoderm and mesoderm

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21
Q

what makes up the hypoblast layer

A

endoderm

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22
Q

name all 6 structures associated with the bilaminar embryonic disc

A

-epiblast layer
-hypoblast layer
-amniotic cavity
-blastocyst cavity
-syntrophoblasts
-cytotrophoblasts

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23
Q

enlargement of the amniotic cavity and migration of cells out of the hypoblast forms what

A

Heuser’s membrane

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24
Q

what will Heuser’s membrane form

A

the internal lining of the blastocyst cavity

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25
Q

once the Heuser’s membrane forms the internal lining of the blastocyst cavity, what is the blastocyst cavity called

A

the yolk sac

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26
Q

once the yolk sac has been formed, what are the cell layers

A

-epiblast
-embryonic mesoderm
-hypoblast

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27
Q

once the yolk sac has been formed, what are the embryonic cavities that are present

A

-amniotic
-yolk sac
-chorionic

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28
Q

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

A

-primitive streak
-Notochord
-Neural tube

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29
Q

Name the three distinct embryonic germ layers of the bilaminar disc during the 3rd week of development

A

-ectoderm
-mesoderm
-endoderm

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30
Q

what are the three parts of the primitive streak

A

-pit
-node
-groove

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31
Q

what is the development of the notochord

A

-primitive node -> notochordal process -> notochord

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32
Q

Describe the process of the formation of the notochord

A

-prenotochordal cells invaginate within the primitive node and migrate towards the cephalad until they reach the prechordal plate
-they then detach themselves from the ectodermal layer to line within the mesoderm forming the notochord

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33
Q

the ______ functions as a primitive skeletal support of the embryo around which the axial skeleton later forms

A

notochord

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34
Q

the notochord induces the formation of

A

somites

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35
Q

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

A

somites

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36
Q

what is the notochord formed from

A

ectodermal cells from the primitive node

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37
Q

what are the three derivatives of mesoderm

A

-paraxial mesoderm
-intermediate mesoderm
-lateral plate mesoderm

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38
Q

what does paraxial mesoderm give rise to

A

somites

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39
Q

what does intermediate mesoderm give rise to

A

urogenital system

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40
Q

what does lateral plate mesoderm give rise to

A

-parietal mesoderm
-visceral mesoderm

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41
Q

what does parietal mesoderm become

A

mesothelial (serous) membranes that cover the peritoneal, pleural, and pericardial cavities

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42
Q

what does visceral mesoderm become

A

forms the thin serous membranes that cover individual organs EX) stomach, pancreas, spleen, etc

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43
Q

name the derivatives of ectoderm

A

-epidermis, hair and nails
-epithelium of oral and nasal cavities and paranasal sinuses
-salivary and endocrine glands
-nervous system
-enamel

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44
Q

what are derivatives of endoderm

A

GI tract epithelium and associated glands

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45
Q

Name 5 neural tube related developmental defects

A

-spina bifida
-meningocele
-meningomyelocele
-meningoencephocele
-anencephaly

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46
Q

what causes spina bifida

A

folic acid deficiency

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47
Q

what is meningocele

A

extrusion of dura and arachnoid mater

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48
Q

what is meningomyelocele

A

extrusion of neural tissue plus all 3 meninges

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49
Q

what is meningoencephalocele

A

extrusion of a ventricular cistern plus neural tissue

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50
Q

what is anencephaly

A

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

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51
Q

what are examples of mild defects of neural tube closure

A

spina bifida and meningocele

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52
Q

what are the intermediate defects of neural tube closure

A

-meningomyelocele
-meningohydroencephalocele (worse)

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53
Q

what is the fatal defect of neural tube closure

A

anencephaly

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54
Q

what is another name for neural crest cells

A

ectomesenchyme neuroectoderm

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55
Q

what 5 things make up the brachial/pharyngeal arches

A

-1st brachial groove
-1st brachial pouch
-2nd brachial pouch
-3rd brachial pouch
-4th brachial pouch

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56
Q

what does the 1st brachial groove form

A

external auditory canal

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57
Q

what does the 1st brachial pouch form

A

eustachian tube

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58
Q

what does the 2nd brachial pouch form

A

palatine tonsils

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59
Q

what does the 3rd brachial pouch form

A

inferior parathyroids and thymus

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60
Q

what does the 4th brachial pouch form

A

superior parathyroids and ultimobrachial body

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61
Q

what period of development are neural crest cells and the brachial/pharyngeal arches associated with

A

embryonic period

3-8 weeks

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62
Q

during what period of time does the growth of the babies body cath up to the growth of the head

A

fetal development

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63
Q

what are the four processes that make up the development of the face

A

-mandibular process
-maxillary process
-lateral nasal process
-median nasal process

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64
Q

what is the precursor for the oral cavity called in the embryo

A

stomodeum

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65
Q

defective fusion of what results in cleft lip

A

defective fusion of the median nasal process with the maxillary process

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66
Q

when do the median nasal process and maxillary process normally fuse

A

5-6 weeks of gestation

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67
Q

defective fusion of what results in cleft palate

A

defective fusion of the palatine shelves

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68
Q

when does fusion of the palatine shelves normally begin and reach completion

A

begins during 8th week and is completed by the 12th week

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69
Q

what percent of all clefts are combined cleft lip and palate

A

45% most common

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70
Q

what percent of clefts are isolated cleft palate

A

30%

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71
Q

what percent of clefts are isolated cleft lip

A

25% Least common

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72
Q

the incidence of cleft lip/palate is highest in what ethnicites

A

-chinese, japanese, native americans, and afroamericans

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73
Q

is cleft lip more common in white populations

A

no

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74
Q

if one child is born with cleft lip, there is a _____ chance of a second child exhibiting the same defect

A

40%

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75
Q

what are some known teratogens involved in congenital malformations

A

-drugs
ethanol, tetracycline, dilantin, lithium, methotrexate, warfarin, thiolidomide, androgens, progesterone, and retinoic acid

-chemicals
methylmercury, polychlorinated biphenyls

-radiation

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76
Q

where does a nasopalatine duct cyst develop

A

at the line of fusion between the palatine shelves and the primary plate

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77
Q

what occurs when a lateral cervical cyst/ brachial fistula forms

A

cervical sinus remains past the 7th week

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78
Q

what is the embryonic precursor associated with thyroid ectoderm and the anterior 2/3 of the tongue

A

brachial arch 1

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79
Q

what are the intermediate structures associated with brachial arch 1

A

-median tongue bud
-foramen cecum
-lateral lingual swellings

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80
Q

what is the intermediate structure associated with the 2nd brachial arch

A

copula/tuberculum impar

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81
Q

does the 2nd branchial arch give rise to an adult structure

A

yes but overgrown by the hypobranchial eminence

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82
Q

what is the intermediate structure associated with the 3rd brachial arch

A

hypobranchial eminence

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83
Q

what adult structure does the 3rd branchial arch give rise to

A

post 1/3 of tongue

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84
Q

what are the intermediate structures of the 4th branchial arch

A

minor contributions to the hypobranchial eminence

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85
Q

does the 4th branchial arch give rise to an adult structure

A

no

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86
Q

what cranial nerve is associated with branchial arch 1

A

trigeminal

sensory to ant 2/3 of tongue

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87
Q

what cranial nerve is associated with branchial arch 2

A

facial

special sensory (taste) to ant 2/3 via the chorda tympani branch

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88
Q

what cranial nerve is associated with branchial arch 3

A

glossopharyngeal

sensory to post 2/3 of tongue

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89
Q

what cranial nerve is associated with branchial arch 4

A

vagus

sensory to extreme post 1/3 via the superior laryngeal branch

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90
Q

what is the cranial nerve associated with branchial arch 6

A

hypoglossal

motor to all tongue muscles

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91
Q

what is median rhomboid glossitis

A

was thought to represent a portion of the tuberculum impar of branchial arch 2, now considered a result of a fungal infection

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92
Q

what causes a thyroglossal duct cyst

A

failure of thyroglossal duct to involute

located at midline of neck

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93
Q

what cartilage forms from branchial arch 1

A

-Merkels Cartilage
mandible
maleus
incus

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94
Q

what cartilage forms from branchial arch 2

A

-Reicharts cartilage
stapes
styloid process
stylohyoid ligament
lesser horn of hyoid

95
Q

what cartilage forms from branchial arch 3

A

greater horn of hyoid

96
Q

what cartilage forms form branchial arch 4

A

thyroid cartilage

97
Q

how many hillocks lead to development of the ear

A

6

98
Q

when does the ear develope

A

embryonic period
3-8 weeks

99
Q

what tissues make up a tooth

A

-enamel
-dentin
-cementum
-pulp

100
Q

what tissues make up peridontium

A

-gingiva
-PDL
-cementum
-alveolar bone

101
Q

How many stages of tooth development are there

A

6

102
Q

what are the 6 stages of tooth development

A
  1. initiation
  2. Bud stage
  3. Cap stage
  4. Bell stage
  5. Apposition
  6. Maturation
103
Q

what occurs during the initiation stage of tooth development

A

cellular induction

104
Q

what occurs during the bud stage of tooth development

A

cellular proliferation

105
Q

what occurs during the cap stage of tooth development

A

proliferation, differentiation, and morphogenesis

106
Q

what occurs during the bell stage of tooth development

A

proliferation, differentiation completed, and morphogenesis (can see all cell layers at this point)

107
Q

what occurs during the apposition stage of tooth development

A

induction and proliferation

108
Q

what occurs during the maturation stage of tooth development

A

maturation

109
Q

Epithelium plays an instructional role during what stage of tooth development

A

pre-tooth bud stage

110
Q

what specifies the dental nature of neural crest cells

A

epithelium

111
Q

once neural crest cells fate has been determined to be tooth, they then specify what

A

tooth type and the nature of the product produced by the epithelium

112
Q

Primitive oral ectoderm becomes what

A

enamel organ

113
Q

what does the enamel organ differentiate into

A

-outer dental epithelium
-stellate reticulum
-stratum intermedium
-inner dental epithelium

114
Q

what differentiates into ameloblasts

A

inner dental epithelium

115
Q

in terms of tooth development, what do neural crest cells differentiate into

A

dental follicle and dental papilla

116
Q

what does the dental follicle differentiate into

A

-PDL
-Cementum
-Alveolar bone

117
Q

what does the dental papilla differentiate into

A

pulp

118
Q

when does the induction stage take place

A

6-7 weeks

119
Q

ectoderm invaginates into what

A

mesenchyme

120
Q

describe the induction stage of tooth development

A

-ectoderm invaginates into mesenchyme and is now called the dental lamina

121
Q

the dental lamina is separated from the surrounding mesenchyme by what

A

a basement membrane

122
Q

when does the bud stage of development occur

A

8th week of development

123
Q

describe the bud stage of tooth development

A

proliferating oral ectoderm make the transition into dental lamina

124
Q

when is the early cap stage of tooth deveopment

A

9-10 week

125
Q

at what stage of tooth development can you differantiate all layers of the enamel organ

A

bell stage

126
Q

what is the function of cells of the outer enamal epithelium

A

protective barrier

127
Q

what is the function of cells of the inner enamel epithelium

A

differentiate into ameloblasts

128
Q

what is the function of cells of the stellate reticulum

A

supportive function in enamel production

129
Q

what is the function of cells in the stratum intermedium

A

differentiate into cementum, PDL, and bone

130
Q

what is the function of cells of the dental papilla

A

outer cells differentiate into odontoblasts and inner cells differentiate into pulp tissue

131
Q

what is described as the junction of the outer and inner enamel epithelia

A

cervical loop

132
Q

what is the site of cemento-enamel junction in the adult tooth

A

cervical loop

133
Q

what is Hertwig’s Epithelial root sheath

A

the fusion and apical extension of the outer and inner enamel epithelia

134
Q

what does Hertwig’s Epithelial root sheath determine

A

the outline of the root dentin and the number of roots a tooth will have

135
Q

when is hertwig’s root sheath removed

A

before the cementum is laid down

136
Q

where does enamel formation stop

A

at the termination of the enamel organ

137
Q

dentin formation continues past the termination of the enamel organ and does what

A

pushes the tooth occlusally

138
Q

when is root length completed

A

1-4 years after the tooth has erupted

139
Q

what does stratum intermedium produce

A

alkaline phosphatase

140
Q

what is the first formed dentin

A

mantle dentin

141
Q

what does mantle dentin contain

A

type I and III collagen

142
Q

collegen fibers in dentin matrix are oriented ________ to the DEJ

A

perpendicular

143
Q

what does mantle dentin stimulate

A

ameloblasts

144
Q

actively secreting ameloblasts are ________ __________ cells

A

tall columnar

145
Q

inactive ameloblasts are _____ __________ or elongated cuboidal

A

short columnar

146
Q

what is the primary cuticle

A

at the final stage of mineralization, the reduced ameloblasts with the remaining cells of the outer epithelium, stellate reticulum, and stratum intermedium form a membrane on the enamel

147
Q

what is anodontia

A

total lack of tooth development

148
Q

what is hypodontia

A

the lack of development of one or more teeth

149
Q

what is oligodontia

A

the lack of development of 6 or more teeth

150
Q

what is hyperdontia

A

the development of an increased number of teeth

151
Q

what are extra teeth called

A

supernumerary teeth

152
Q

when in tooth development do supernumerary teeth develope

A

a defect that originates in the initiation stage

153
Q

what is the most common manifestation of supernumerary tooth formation

A

mesodens

154
Q

what is an odontoma

A

growth of dental materials with no distinct aznatomy

155
Q

when in tooth development does an odontoma form

A

during the initiation stage

156
Q

what does an odontoma consist of

A

dentin, cementum, enamel

157
Q

what is a complex odontoma

A

a conglomerate mass of enamel an dentin that bears no anatomic resemblance to a tooth

158
Q

what is a compound odontoma

A

multiple small tooth like structures

159
Q

what casues root abnormalities

A

an issue with the epithelial diaphragm in Hertwigs Root Sheath

160
Q

what is taurodontism

A

an enlargement of the body and pulp chamber of multirooted teeth with apical displacement of the bifurcation

(very long root trunk and very short roots)

161
Q

what is a dilaceration

A

an abnormal angulation or bend in the tooth root

162
Q

what does gemination result in

A

a large single rooted tooth with one pulp cavity and exhibits twinning in the crown area

163
Q

when in tooth formation does gemination occur

A

during the cap stage

164
Q

what is the tooth count in the case of gemination

A

tooth count is normal when the double tooth is counted as one

165
Q

what is the tooth count in fusion

A

refers to a double tooth in which the tooth count reveals a missing tooth when the double tooth is counted as one

166
Q

what is concrescence

A

union of root structure of two or more teeth by cementum

167
Q

when does concrescence occur

A

during the apposition and maturation stages

168
Q

what is tubercule formation

A

a defect that results in an extra cusp due to effect on enamel organ

169
Q

when does tubercule formation occur

A

during the cap stage

170
Q

what is a dentigerous cyst

A

originates by separation of the dental follicle from the crown of the unerupted tooth

the cyst is attached at the CEJ

171
Q

what type of cyst comprises 20% of all jaw cysts

A

dentigerous cysts

172
Q

what does a odontogenic keratocyst arise from

A

cell rests of the dental lamina (rests of Serres)

173
Q

OKC consist of _____ of all odontogenic cystst

A

3-11%

174
Q

what age group is most diagnosed with OKC

A

10 and 40 years old make uo 60% of all cases

175
Q

where are OKC found most commonly

A

65% in mandible

176
Q

OKC are ______ ___________ cysts

A

bone expanding

locally invasive

177
Q

OKCs located in the posterior mandible often present as

A

multilocular lesions

178
Q

what is the tx for OKCs

A

surgical removal

179
Q

what is the recurrence rate of OKCs

A

30%

180
Q

describe the histology of an OKC

A

6-8 cell layer of SSE with parakeratosis at the luminal surface. lumen is often filled with keratin

181
Q

what is the most common neoplastic lesion arising from odontogenic epithelium

A

ameloblastoma

182
Q

describe the histology of an ameloblastoma

A

slow growing and locally invasive tumor

multilocular soap bubble appearancew

183
Q

when looking at a radiograph of a ameloblastoma how will th etumor appear

A

multilocular

184
Q

ameloblastomas are resistant to what form of tx

A

radio-resistant

185
Q

is enamel cellular or acellular

A

acellular

186
Q

does enamel have collagen in its matrix

A

no

187
Q

how much harder than dentin is enamel

A

5x

188
Q

what is the hardest tissue in the body

A

enamel

189
Q

what is the stucture enamel is packaged into

A

ca HA crystals in enamel rods

190
Q

what percentage mineral is enamel

A

96%

191
Q

what percentage water is enamel

A

1%

192
Q

what percentage of enamel is made up of organic components

A

3%

193
Q

what protein constitutes 90% of protein in enamel

A

amelogenin

194
Q

what makes up 5% of enamel proteins

A

enamelin

195
Q

what enamel protein is found in enamel tufts at CEJ

A

tuftelin

196
Q

what physical properties does amelogenin exhibit

A

thixotropic

197
Q

what does thixotrophic mean

A

the ability to flow under pressure

198
Q

what is the largest enamel protein

A

enamelin

199
Q

where is enamelin restricted to

A

enamel rod areas

200
Q

where is tuftelin restricted to

A

the DEJ in enamel tufts

201
Q

what is thought to be the role of enamelin

A

plays a role in crystal growth and nucleation

202
Q

what is thought to be the role of tuftelin

A

play a role in induction, the initiation of mineralization, and possibly functions as a junctional protein linking enamel and dentin

203
Q

where is sheathlin found

A

througout the rod and interrod enamel

preferentially in the rod sheaths

204
Q

neural crest cells induce the formation and proliferation of

A

the dental lamina

205
Q

inner enamel epithelium induces the differentiation of

A

odontoblasts

206
Q

what are the 5 stages of ameloblast function

A
  1. morphogenic stage
  2. differentiation stage
  3. secretory stage
  4. maturation stage
  5. protective stage
207
Q

how many ameloblasts contribute to the compostion of one enamel rod

A

4

208
Q

name the 7 structural features of enamel

A

-striae of Retzius
-Perikymata
-Hunter-Schreger bands
-Gnarled enamel\
-Enamel lamellae
-enamel tufts
-enamel spindle

209
Q

what are striae of retzius

A

incremental lines produced by periodic constriction of tomes process associated with corresponding increase in the face forming the interrod enamel

210
Q

cross striations on each rod represent _____ hours of enamel matrix production

A

24

211
Q

what are perikymata

A

external manifestations of the striae of Retzius

212
Q

what are Hunter Schregar bands

A

an optical phenomenon produced by changes in direction of enamel rods

213
Q

what is gnarled enamel

A

enamel rods appear to be twisted in a complex arrangment

very resistant to fracture and abbrasion

214
Q

where is gnarled enamel most commonly found

A

cusp tips

215
Q

what is enamel lamellae

A

hypomineralized areas of enamel extending from the DEJ for considerable distnaces into the enamel

216
Q

what may be involved in smooth surface caries

A

enamel lamellae

217
Q

what is an enamel crack

A

cracks extending from the enamel surface to variable distances into the enamel

may extend into the dentin

218
Q

what are enamel tufts

A

hypomineralized areas of enamel at the DEJ that are rich in enamelin and tuftelin

219
Q

what are enamel spindles

A

extensions of odontoblastic processes and tubules across the basal lamina during tht inital stages of matrix formation

220
Q

what is hypomineralization primarily related to

A

delay in the removal of amelogenin during maturation

birthing difficulties and nutritional deficiencies also commonly disturb development

221
Q

what is hypoplasia of enamel generally induced by

A

infectious diseases of childhood

measles, rhematic fever, mumps

which leave a defect in the parts of the teeth activley developing at the time of infection

222
Q

what is fluorosis

A

mottled enamel occurs as a result of a diet containing high levels of fluoride

223
Q

what is amelogenesis imperfecta

A

defective enamel matrix deposition, which in turn voids the possibility of enamel mineralization

224
Q

what is the more common type of amelogenesis imperfecta

A

autosomal dominant

225
Q

what are enamel pearls and cervical enamel projections

A

defects that occur during the apposition and maturation stages due to displacement of ameloblasts to the root structure

226
Q

what teeth are enamel pearls most often seen in

A

max molars

227
Q

what teeth are CEPs most often involved in

A

mand molars

228
Q

what is a dens in dente

A

a deep invagination of the crown or root that is lined with enamel

229
Q

what tooth is most commonly affected by dens in dente

A

max incisor

230
Q

what is the range of enamel thickness over the cusps

A

2-2.5 mm

231
Q

what is the neonatal line

A

represents an exaggerated hypomineralized striae of retzius that forms at birth

232
Q

what is another name for perikymata

A

imbrication lines of pickerill

233
Q

what is the enamel cuticle composed of

A

remnants of the reduced enamel epithelium

234
Q

what is the enamel pellicle comprised of

A

glycoprotein precipitates derived from saliva and or gengival crevicular fluid

Histopath (1 decks)

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