Oral Cavity and Tooth Development Flashcards
1
Q
What bounds the oral cavity superiorly?
A
- hard and soft palate
2
Q
What binds the oral cavity inferiorly?
A
- tongue and floor of mouth
3
Q
What binds the oral cavity anterior and lateral?
A
- teeth
4
Q
What binds the anterior cavity posteriorly?
A
- oropharynx
5
Q
What is the area enclosed between lips and teeth
A
- vestibule
6
Q
what is transitional zone between external haired skin and internal oral mucosa?
A
- vermillion border
7
Q
Where does the color in the oral cavity come from?
A
- derived from highly vascular dermis and thin overlying keratinized epidermis
8
Q
Do the lips have sweat and sebaceous glands?
A
- nope
9
Q
Why are the lips highly sensitive?
A
- due to a rich sensory innervation
10
Q
What is the oral cavity responsible for?
A
- ingestion
- fragmentation
- moistening of food
11
Q
______ involves cutting, chewing, and grinding of food by occlusal surfaces of teeth
A
- Mastication
12
Q
What forms the dental arcade?
A
- teeth
13
Q
What are some other functions the oral cavity is involved in?
A
- speech
- facial expression
- sensory perception
- respiration
14
Q
what are the lips themselves know as?
A
- vermillion border
15
Q
Why do lips require constant moistening to prevent cracking?
A
- lack sweat and sebaceous glands
16
Q
What is the salivary glands role in digestion?
A
- moistening the food to create bolus for swallowing (deglutition)
17
Q
What assists the oral cavity in mastication?
A
- lips
- tongue
- salivary glands
18
Q
_____ non - keratinized mucosa found on inner cheeks, floor of mouth, inferior surface of tongue and soft palate
A
- lining mucosa
19
Q
What does non-keratinized mean?
A
- lacks a stratum corneum
20
Q
______ present in areas of high abrasion, eg gingiva (gums) and hard palate
A
- masticatory mucosa
21
Q
IS the masticatory mucosa keratinized?
A
Yes or
parakeratinized
22
Q
_____ is when cells of stratum corneum do not lose nuclei
A
- parakeratinized
23
Q
What is thicker, parakeratinized or non keratinized?
A
- parakeratinized
24
Q
Do the cells at the surface remain living in parakeratinized epithelium?
A
- yes
25
_______ mucosa is restricted to dorsal surface of tongue
- specialized mucosa
26
Is specialized mucosa keratinized?
- Yes
27
What is the tongue composed of?
- it is a muscular organ composed of interlacing skeletal muscle fibers
28
_____ is specialized for manipulation of food and sensation of taste
- tongue
29
Does the the tongue have accessory salivary glands scattered throughout the tongue musculature?
- YES
30
Where are the salivary glands in the tongue located?
- within lamina propria and between muscle layers
31
Why does the tongue have such a wide range of movement?
- the orientation of muscle fibers
32
what innervates the tongue?
-various cranial nerves
33
What nerves innervate the tongue?
- V
- VII
- IX
- X
- XII
34
What nerve is responsible for general sensation anterior to sulcus terminalis?
- V
35
What nerve is responsible for taste?
- VII
36
What nerve is responsible for general sensation and taste posterior to sulcus terminalis?
- IX
37
What nerve is responsible for taste and potentially motor?
- X
38
What nerve is responsible for motor function in the tongue?
- XII
39
What supports the tongue inferiorly?
- frenulum
40
_____ is a thin band of connective tissue anchoring tongue to floor of mouth
- frenulum
41
The anterior 2/3 of the tongue is derived from?
- ectoderm
42
The posterior 1/3 of the tongue is derived from?
- pharynx (mesoderm)
43
What separates the anterior 2/3 and post. 1/3 of the tongue?
- a groove called sulcus terminalis
44
What epithelium covers the tongue?
- stratified squamous epithelium
45
Is the epithelium of the tongue keratinized?
- only in the anterior 2/3
46
What shape is the sulcus terminalis?
- V shaped
47
What is the most numerous lingual papillae?
- filiform papillae
48
_____ papillae is keratinized, short bristles, distributed in parallel rows
- filiform papillae
49
Do filiform papillae have taste buds?
- no they are primarily tactile
| ( prominent in cats) reason cats tongues are so rough
50
What is the function of filiform papillae in carnivores?
- scrape meat off of bone
51
______ papillae are mushroom shaped scattered among filiform papillae
- fungiform
52
What papillae are located in furrows/ridges on lateral portion of tongue?
- foliate papillae
53
Which papillae is associated with lateral taste buds?
- foliate papillae
54
What papillae has taste buds in children but degenerates with age?
- foliate papillae
55
What papillae is associated with salivary glands (von ebner's glands) at base of papilla?
- foliate papillae
and
- circumvallate papillae
56
_________ papillae - row of 8-12 large dome shaped papillae?
- circumvallate papillae
57
What papillae is located immediately anterior to sulcus terminalis?
- circumvallate papillae
58
What papillae is surrounded by moat like sulcus, containing large #'s of taste buds laterally around base?
- circumvallate papillae
59
Where are taste buds located in humans?
- on papilae of tongue (except filliform)
60
Where else are taste buds located?
- over palate, pharynx, and epiglottis
61
What is responsible for change in taste with age?
- taste buds degenerate past age 45
62
Taste buds
- consists of up to 20-30 spindle shaped central taste cells (= gustatory cells) containing terminal taste hairs
63
____ project from surface of cell into a central taste pore
- taste hairs
64
What covers taste hairs
- glycoprotein coat
65
What surrounds taste hairs?
- sustentacular cells and basal cells
66
Are taste cells continuously lost and replaced?
- YES
67
Why do you have decreased sense of taste when you burn mouth?
- you have burned off taste cells that need to regrow
68
What are the four basic tastes
- sweet, sour, bitter and salty
69
Do taste cells contain receptors for multiple tastes?
- no but taste buds contain a mixture of taste cells
70
What papillae do bitter taste receptors concentrate on?
- circumvallate
71
what acts a carrier medium and stimulates taste hairs?
- saliva
72
What is the fifth taste that was recently discovered?
- unami (savory)
73
____ detects certain amino acids including glutamate, aspartate, which is characteristic of asparagus, tomatoes, beef, cheese, and MSG
- unami (savory)
74
What papillae is umami associated with?
- circumvallate
75
IS there a genetic basis for taste?
- Yes
76
How do you taste for taste?
- PTC paper
- Tasters = bitter
- Non tasters = nothing
77
What is the decreased ability to detect taste?
- hypogeusia
78
What is the condition where taste buds are totally absent?
- Type I familial dysautonomia
79
Recent evidence for 6th taste for fat
- True
80
____ is underlying mucosa in caudal 1/3 and is a mass of lymphoid tissue
- lingual tonsil
81
What do the palatine, pharyngeal, and lingual tonsil make up?
- ring referred to as Waldeyers ring
82
what is the function of Waldeyers ring?
- to protect respiratory and digestive tract
83
______ is an extension of posterior free margin of soft palate
- Uvula
84
what is the central core of the uvula made up of?
- skeletal muscle
85
What covers the uvula?
- lining mucosa with large numbers of. submucosal (palatine) glands
86
Does the uvula prevent food from entering nasal cavity during swallowing?
- probably not because the uvula is a single midline structure and the openings to the nasopharynx are paired and lateral
87
What are the three major pairs of salivary glands?
- parotid
- submandibular
- sublingual
88
What is the largest gland that is located on the cheeks and primarily serous?
- parotid
89
_____ opens within vestibule, opposite upper 2nd molar
- parotid duct/stenson's duct
90
What gland is located below the tongue and mostly mucous?
- sublingual
91
What gland is located inferior and medial to ramus of mandible?
- submandibular
92
Is the submandibular gland a mixed gland?
- Yes
93
What duct opens at sublingual caruncle
- submandibular/Wharton's duct
94
What are some of the numerous smaller, accessory glands scattered throughout the oral mucosa?
- lingual, labial, buccal, molar and palatine glands
95
What is the function of intercalated ducts?
- secrete HCO3 and resorb Cl
96
What are intercalated ducts?
- small ducts lined by simple cuboidal epithelium
97
What type of cells surround acini and their contraction aids in secretion of saliva into ducts?
- myoepithelial cells
98
Acini are serous or mucous?
- both
99
serous scini of mixed glands often in form of _____
- demilunes
100
what is the epithelium of large striated ducts?
- simple cuboidal to columnar epithelium
101
why are they called striated ducts?
- possess basal striations due to folding of plasma membrane
102
what is the function of striated ducts?
- resorb Na, secrete K into saliva, and also secrete lysozyme and IgA
103
What do striated ducts empty into?
- large excretory ducts
104
What is the epithelium of large excretory ducts?
- stratified cuboidal
or
- pseudo stratified columnar epithelium
105
What leads to thick viscous saliva that is rich in protein (mucus)
- sympathetic stimulation
| inhibits aqueous secretion
106
What stimulation results in copious watery saliva?
- parasympathetic stimulation
107
What does saliva contain?
- water
- glycoproteins (mucus)
- proteins (enzymes and antibodies)
108
What enxyme converts starch to sugar?
- amylase
109
What enzyme is an antibacterial?
- lysozyme
110
What antibodies are present in saliva?
- IgA
| - inorganic ions (Ca, P, Cl)
111
Saliva is also high in K, low in Na, and high in bicarbonate (HCO3-)
True
112
What are the functions of saliva?
- moistens oral mucosa and dry food
- provides carrier medium for sense of taste
- buffering via high bicarbonate content
- digestion of carbohydrates via amylase
- immunologic function (secretion of IgA)
- control of bacterial flora
113
How does saliva have a role in control of bacterial flora?
- proteins in saliva cover teeth with acquired pellicle
- pellicle contains Ab's that prevent tooth decay
- decreased salivary production exacerbates tooth decay
114
What is the portion of tooth that projects into oral cavity?
- crown
115
What protects the crown?
- layer of highly mineralized enamel
116
_____ is a hard translucent substance containing less than 1% organic material and 96-98% hydroxyapatite
- enamel
117
What part of jaw is the tooth embedded in?
- alveolar ridge
118
Tooth socket
- alveolus
119
What secretes enamel?
- tall, columnar ameloblasts of enamel organ
120
What does the apical secretory end of ameloblast form?
- single large tomes process
121
Is enamel mineralization uniform?
- no it is non uniform and results in highly calcified enamel rods or prisms
122
What shape are the enamel rods?
- hexagonal
123
What separates the enamel rods?
- less mineralized interprismatic material
124
Enamel rods extend from ameloblasts at enamel surface to dentino-enamel junction
- true
125
Each prisms is product of single ameloblast T/F
- true
126
What makes up of the bulk of the tooth?
- dentin
127
Is dentin more or less mineralized than enamel?
- less
128
What secretes dentin?
- odontoblasts of dental papilla
129
Is dentin mineralized as it is secreted?
- no it is non mineralized pre-dentin
130
Dentin is more mineralized than bone (T/F)
- True
131
Dentin contains type 1 collagen and GAG's? (T/F)
- True
132
_____ is arranged in dentine tubules
- dentin
133
Dentine tubules
- hollow, parallel tubes radiating from pulp cavity
134
Dentine tubules contain
-long rod like cytoplasmic processes of odontoblasts (tomes fibers)
135
______ contains support structures like sensory nerves and blood vessels
- central pulp cavity
136
_______ is mesodermal in origin; and resembles primitive mesenchyme
- dental pulp
137
What does the dental pulp contain?
- stellate fibroblasts
- reticular fibers
- collagen
- ground substance
138
How is the pulp supplied?
- richly supplied by capillaries from arterioles running with periodontal ligament
139
Dental pulp has stem cell capabilities
- yes
140
Dentine innervated by myelinated nerves
- True
141
What covers the tooth root?
- thin layer of cementum (also mesodermal)
142
What is the composition of cementum?
- amorphous, collagen-based, calcified tissue
| - 45-50% hydroxyapatite similar to bone
143
What forms cementum?
- cementoblasts (mature into cementocytes)
144
How is the cementum layer anchored to bone of alveolus?
- with fibers of periodontal ligament or membrane
145
What is the peridontal ligament made up of?
- composed of dense collagenous fibers called sharpey's fibers
146
At what angle do the sharpeys fibers run?
- oblique angle
147
Does the peridontal ligament allow movement?
- yes during mastication if not chewing would be extremely painful
148
What are epithelial rests of Malassez?
- occasional clusters of epithelial cells within periodontal ligament
149
What is the region of tooth between root and crown?
- neck
150
What protects the neck of the tooth?
masticatory oral mucosa called gingiva (covers upper portion of alveolar ridge)
151
What gingiva covers upper alveolar bone?
- attached gingiva
152
What gingiva forms cuff around neck of tooth
- free gingiva
153
What is the space between gingiva and crown?
- gingival sulcus or crevice
154
what lines the gingiva?
- crevicular epithelium
155
______ is very thin (only 2-3 cells thick, easily breached by bacteria)
- crevicular epithelium
156
What does breaching of the crevicular epithelium by bacteria lead to?
- peridontal disease and gingivitis
157
What are the tissues that surround and support the tooth collectively reffered to as?
- peridontium
158
what includes the peridontium?
- epithelium
- cementum
- periodontal ligament and alveolar bone
159
What forms the developing tooth bud?
- ameloblasts of enamel organ and odontoblasts of dental papilla
160
Tooth is formed between opposing layers of what epithelial cells?
- ameloblasts of enamel organ
| - odontoblasts of dental papilla
161
what is the origin of enamel?
- ectodermal origin
162
What develops from the mesodermal region?
- Dentine
- Cementum
- Pulp
- Peridontal ligament
163
during what week of fetal development does a horseshoe-shaped ridge arise from oral epithelium?
- 6th week
164
what does the horseshoe epithelial ridge form?
- dental lamina in position of future jaws
165
What develops in each quadrant?
- lamina develops several globular, ectodermal swellings (one for each deciduous tooth)
166
What does the superficial half forms?
- enamel organs
167
What does the deep half form?
- dental papilla
168
Odontogenesis steps
1. Enamel organ initially cup-shaped (cap stage)
| 2. Cells of enamel organ progressively differentiate to become stellate reticulum (with extreacellular matrix of GAG's)
169
The outer convex surface of the bell shaped enamel organ becomes?
- external enamel epithelium
170
The inner concave surface of enamel organ form?
- internal enamel epithelium
171
What does the internal enamel epithelium differentiate into?
- tall columnar ameloblasts
172
Amelogenesis
- enamel formation
173
what produces enamel?
- ameloblasts
174
What does the primitave mesenchyme develop into?
- dental papilla
175
What do the cells lining the convex surface of dental papilla develop into?
- odontoglasts
176
Dentinogenesis
- dentin formation
177
What does it mean that these two cell layers in apposition
- tooth forms between them
178
What do the two cell layers form
- future incisors, canine, molars of primary dentition
179
What induces the differentiation of odontoblasts?
- development of ameloblasts
180
What induces the deposition of enamel?
- calcification of dentin
181
What initiates tooth formation?
- deposition of organic pre-dentine by odontoblasts on surface of dental papilla
182
What induces enamel production by ameloblasts?
- calcification of dentin matrix
183
What form the dentin tubules?
- odontoblasts process that are embedded in dentin matrix
184
Where does enamel form?
- enamel rods separated by interprismatic material
185
What becomes the dental pulp?
- dental papilla
186
when do enamel organ and ameloblasts degenerate?
- at time of tooth eruption
187
How does tooth erupt?
- overlying mucosa separates exposing crown
188
T/F After tooth formation is complete small amounts of 2' continue to be produced and this makes the tooth stronger.
- False it can obliterate the pulp cavity
189
What determines overall shape of tooth crown?
- enamel organ
190
Outer rim of enamel organ know as __________________ determines cross sectional outline of tooth?
- epithelial sheath of Hertwig = (Hertwig's root sheath)
191
What does the surrounding mesenchyme form?
- dental follicle (leads to periodontal ligament)
192
What do the enamel organs of permanent teeth develop as?
- buds from dental lamina and deciduous enamel organ
193
in case of molars
- dental lamina proliferates caudally to form enamel organs of 2' dentition
194
When does tooth development begin?
- 6th week of fetal development
195
When does tooth eruption occur?
- 6-30 months after birth (breast feeding stops here)
196
If administered during development of permanent dentition what leads to yellow discoloration of teeth?
- Tetracycline
197
How many primary teeth do humans have?
- 20
198
How many permanent teeth do humans have?
- 32
199
How many primary molars do humans have ?
- 2
200
Human dental formula
I 2/2 C1/1 P 2/2 M 3/3
201
When do molars erupt?
- no precursors
| - 6, 12, and 18 -21 years of age
202
Homodont dentition
- all teeth similar
203
Incisors
- modified for cutting and biting
204
Canines
- for puncturing and holding
205
Tongue stud
- has distinct arc like wear pattern on backs of incisors
206
TMJ
- allows lateral and anterior posterior motion which is important for chewing and grinding
207
Raised points on occlusal surfaces of molars and premolarls know as ____
- cusps
| - (include protocone, metacone, paracone)
208
The flattened posterior surface of lower molars know as_____
- talonid
209
Premolars and molars can be low crowned or ______ inn omnivores
- bunodont
210
May be very tall high crowned _____ as in herbivores
- hypsodont
211
Premolars variously modified shearing _______ in carnivores
- carnassials
| act like scissors to shear meat off of bone
212
How can predict age of horse?
- enamel wear pattern
213
Hadrosaur teeth
- dental batteries
- fused plates of teeth
- leaflike arrangements
- can see enamel rods
214
Multituberculates teeth
- function as grinding wheel
| - millstone function
215
How is orthodontic correction by?
- osteoblast and osteoclast activity
216
_____ results when weak acids in food and drink erode calcified enamel augmented by bacterial action
- dental caries
217
____ helps harden enamel and kills bacteria
- fluoride
218
caries may extend into dentin or pulp cavity produce abscesses or death of tooth and leads to
- root canal
219
Why are vitamin C tablets dangerous?
- they can lead to acid deposition in teeth that destroy teeth
220
_______ is caused by accumulation of calcified food and bacterial debris in gingival sulcus
- periodontal disease
221
What does periodontal disease lead to?
- widening of gingival sulcus, possible inflammation and destruction of periodontal ligament
222
Gingivitis
- inflammation of gums
223
Periodontitis
- inflammation of periodontal ligament
