Histology Of Oral Cavity

Question 1

1. Oral cavity is lined by which of 3 epithelium?

2. What is parakeratinized mean?

Answer 1

1. Keratinized, parakeratinized, or nonkeratinized stratified squamous
2. Surface cells are keratinized, but retain their nuclei

Question 2

Keratinized stratified squamous:

1. Function
2. What 2 places of the oral cavity have it
3. Location of lamina propria in these regions?

Answer 2

1. Resists damage from abrasion
2. Masticatory mucosa of gingiva and hard palate
3. Directly on periosteum of underlying bone

Question 3

Nonkeratinized stratified squamous

1. In lining mucosa of what 5 regions?
2. Lining mucosa overlies what in these regions?

Answer 3

1. Soft palate, cheeks, inner lips, inferior surface of tongue and floor of mouth
2. Submucosa containing many minor salivary glands

Question 4

Outer surface of lips contains what 3 things?

Answer 4

Sweat glands, hair follicles, and sebaceous glands

Question 5

1. Where is vermilion zone?
2. Type of epithelium
3. Contains
4. Lacks what 2 things
5. How is it kept moist?

Answer 5

1. Between skin and oral mucosa of lips
2. Lightly keratinized
3. Rich microvasculature (imparts pink color)
4. Salivary or sweat glands
5. Saliva

Question 6

Dorsal mucosa on anterior 2/3 of tongue contains? Which are?

Which type is the most numerous?

Answer 6

Hundreds of papillae; elevations of mucus membrane

Filiform

Question 7

Filiform papillae:

1. Shape
2. Epithelium
3. Function

Answer 7

1. Elongated cones
2. Heavily keratinized
3. Provide rough surface that facilitates handling of food

Question 8

Fungiform papillae:

1. Location
2. Shape?
3. __ and __ cores of lamina propria

Answer 8

1. Interspersed among filiform papillae
2. Mushroom shaped
3. Well vascularized and innervated

Question 9

Foliate papillae:

1. Location

Answer 9

1. Ridges on lateral side of tongue

Question 10

Vallate (circumvallate) papillae:

1. Location
2. Each papilla is surrounded by a groove; significance?
3. Function of these glands?

Answer 10

1. These are the largest; located anterior to terminal sulcus
2. Ducts of serous salivary glands (von Ebner glands) empty into this groove
3. Wash away food particles so taste buds can receive/process new stimuli

Question 11

Posterior to sulcus terminalis there is a large amount of ?

Answer 11

Diffuse lymphoid tissue/nodules with germinal centers which constitute the lingual tonsil

Question 12

1. Lingual tonsil is part of?

2. Consists of what 4 tonsils?

Answer 12

1. Waldeyer tonsillar ring

2. Palatine, lingual, tonsil, and pharyngeal (adenoid)

Question 13

Taste buds:

1. Function
2. Located on all papilla except?
3. What other 3 places are they located

Answer 13

1. Sample general chemical composition of ingested material
2. Filiform
3. Mucosa of epiglottis, soft palate, and posterior wall of pharynx

Question 14

Taste buds have what 3 types of cells?

Base of taste buds are located? What happens here?

Answer 14

Gustatory, supportive and basal (stem) cells

On basal lamina; entered by nerve fibers that form synapses with gustatory cells

Question 15

1. Where is the taste pore located?
2. What projects into taste pores?
3. What are tastants? Where do they bind?

Answer 15

1. Apical end of taste bud
2. Microvilli from apical ends taste cells
3. Molecules that generate taste; bind to receptors in plasma membrane of microvilli taste cells

Question 16

1. Children have how many teeth?

2. 2 incisors, 1 canine, and 2 molars are located where?

Answer 16

1. 20

2. In each half of maxillary and mandibular dental arches

Question 17

1. Adults have how many teeth?

2. Which extra teeth are located in each half of maxillary and mandibular dental arches

Answer 17

1. 32

2. This space has 3 molars instead of 2 and also contains 2 premolars

Question 18

Describe each part of the tooth:

1. Crown
2. Root
3. Neck

Answer 18

1. Projects into oral cavity from gingiva
2. Fixed in alveolus by periodontal ligament/membrane
3. Between crown and root (slightly constricted part)

Question 19

Most of the tooth is composed of? What is it covered by in crown and root?

Answer 19

Dentin; covered by enamel over crown and cement over root

Question 20

Pulp cavity contains?

Root canal transmits nerves and vessels where? Thru?

Answer 20

LCT, blood and lymph vessels, and nerves

To and from pulp cavity thru apical foramen

Question 21

Dentin:

1. What about its composition makes it harder than bone
2. Produced by? How?

Answer 21

1. Dentin is 70% hydroxyapatite; bone is 50-65%

2. Odontoblasts; secrete predentin matrix that is mineralized to become dentin

Question 22

Odontoblasts:

1. Derived from?
2. Location
3. Location of its processes?
4. Processes are important for
5. Why do they continue predentin production into adult life?

Answer 22

1. Neural crests
2. Line tooths pulp cavity
3. Extend from apical surface of odonoblasts and penetrate thickness of dentin within dentinal tubules
4. Maintenance of dentin matrix
5. Gradually reduce size of pulp cavity and can repair dentin if tooth is damaged

Question 23

Dentin:

1. Unmyelinated nerve fibers extend from where to where?
2. Stimulated by?

Answer 23

1. Pulp cavity into dentinal tubules along odontoblast processes
2. Stimuli like cold, heat, and acidic pH - produce tooth sensitivity

Question 24

1. Why is enamel the hardest component of human body
2. Enamel containing fluoride is more resistant to?
3. What else contributes to enamels hardness/resistance?

Answer 24

1. 96% hydroxyapatite
2. Acidic dissolution caused by microorganisms (without fluoride, tooth is more likely to decay)
3. Consists of uniform interlocking columns that extend thru entire thickness of enamel layer

Question 25

1. What produces enamel? 2. Derived from? 3. Why cant enamel be replaced

Answer 25

1. Ameloblasts 2. Ectodermal lining of embryonic oral cavity 3. Ameloblasts are lost once tooth erupts (because they are located on the surface, not on the bottom)

Question 26

Periodontium: 1. Includes what 4 structures? 2. Responsible for?

Answer 26

1. Cementum, periodontal ligament, alveolar bone, and gingiva 2. Maintaining teeth in maxillary and mandibular alveolar processes

Question 27

Cementum: 1. Location 2. Similar to bone except? 3. Produced by

Answer 27

1. Covers dentin of root of tooth 2. Avascular 3. Cementoblasts

Question 28

Cementoblasts: 1. Secrete? 2. During cementum formation, what happens to cementoblasts? 3. What contains cementocytes and their processes?

Answer 28

1. ECM that undergoes mineralization 2. They are incorporated into cementum and become cementocytes 3. Lacunae and canaliculi in cementum

Question 29

Difference between cementocytes in lacunae vs canaliculi

Answer 29

In lacunae, they are irregularly distributed. In canaliculi they do not form an interconnected network like in bone

Question 30

Peridontal ligament (membrane): 1. Composed of 2. Has bundles of __ that bind what 2 things? 3. Why is it unlike typical ligaments?

Answer 30

1. Fibrous connective tissue 2. Collagen (Sharpey fibers) that bind cementum and alveolar bone 3. It is highly cellular and has a rich supply of blood vessels/nerves

Question 31

Salivary glands: 1. Type of glands 2. Empty into? 3. Has what 3 types of functions 4. 3 major salivary glands 5. Secretes

Answer 31

1. Exocrine 2. Oral cavity 3. Digestive, lubricating, and protective 4. Parotid, submandibular and sublingual 5. Saliva

Question 32

Each major salivary gland is surrounded by? Be specific

Answer 32

Connective tissue capsule - parenchyma consisting of secretory units and branching duct system arranged in lobules separated by septa of connective tissue

Question 33

Saliva from parotid is __; submandibular/sublingual saliva is__; salvia from minor salivary glands is mostly __

Answer 33

Serous (watery); seromucus; mucus

Question 34

Salivary secretory units consist of what 3 cell types

Answer 34

Serous cells, mucus cells, and myoepithelial cells

Question 35

Serous cells: 1. Secrete? 2. Shape/structure?

Answer 35

1. Proteins/enzymes | 2. Pyramidal with round basal nuclei and well developed rER and apical secretory granules

Question 36

Mucus cells: 1. Shape/structure 2. Have poorly staining?

Answer 36

1. Pyramidal with a more compressed basal nuclei | 2. Apical mucin granules

Question 37

Myoepithelial cells: 1. Located where? 2. Surrounds what 3 things? 3. Have contractile processes around secretory unit/duct that are important for?

Answer 37

1. Basal lamina 2. Acini, tubules and proximal ends of duct system 3. Moving secretory products into and thru ducts

Question 38

1. __ empty into short intercalated ducts 2. Short intercalated ducts are lined by what type of cells? 3. These ducts join to form _

Answer 38

1. Secretory acini 2. Cuboidal epithelial cells 3. Striated duct

Question 39

Striated ducts: 1. Lined by what type of cells; have numerous 2. Cells absorb __ and folded cell membrane provides __; this facilitates?

Answer 39

1. Columnar epithelial cells; mitochondria 2. Na ions and cell membrane provides large surface area for ion transporters; rapid ion transcytosis and makes secretions slightly hypotonic

Question 40

IgA 1. What cells release it/where are these cells located 2. Where does it bind 3. How is it internalized 4. What is its function

Answer 40

1. Plasma cells in CT surrounding secretory units and small ducts 2. Receptor in basal plasma membrane 3. Receptor-mediated endocytosis; carried thru cell to apical plasma membrane then released to lumen 4. Provides defense against specific pathogens in oral cavity

Question 41

Excretory ducts: 1. Ultimately connect to? 2. Epithelium of small excretory ducts? 3. Epithelium gradually changes to? 4. Epithelium then changes to __ as it approaches oral cavity

Answer 41

1. Oral cavity 2. Simple cuboidal 3. Stratified cuboidal or pseudostratified columnar 4. Stratified squamous

Question 42

1. Which gland exclusively has serous acini | 2. What does serous acini secrete? Why?

Answer 42

1. Parotid | 2. Alpha amylase to initiate hydrolysis of carbs and proline-rich proteins with antimicrobial properties

Question 43

Submandibular gland is mostly serous acini, but also has __ | Secretes alpha amylase and proline rich proteins as well as __, why?

Answer 43

Mucus secretory units capped by serous demilunes | Lysozyme for hydrolysis of bacterial walls

Question 44

What predominates in sublingual gland? | What is rarely present?

Answer 44

Mucus secretory units | Pure serous acini is rarely present