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Oral Histology > Oral Mucosa > Flashcards

Flashcards in Oral Mucosa Deck (71):
1

What is the mouth, nasal passages, and GI tract lined by?

Mucous membrane

2

What 2 tissues make up a mucous membrane?

Epithelium
Underlying Connective tissue

3

What makes up the underlying connective tissue?

Lamina propria
Sometimes the submucosa

4

What layer are blood vessels located in the mouth?

Lamina propria or Submucosa

5

What layer are minor salivary glands located?

Submucosa

6

Where are ducts from minor and major salivary glands located?

Travel through the connective tissue to communicate with the mucosal surface

7

What are the functions of oral mucosa?

Protection
Aid in digestion
Sensory innervation

8

What are the types of protection the Oral mucosa provieds?

Barrier
Anti-microbial

9

Barrier defense of oral mucosa

Epithelium provides a physical barrier for things to not come into contact with deeper underlying tissues

10

Anti-microbial defense of the oral mucosa

Immune cells are found mostly in the lamina propria, but also found in the epithelium

11

B-defensins

Anti-microb secreted by teh superficial epithelium of the oral cavity
Large amount is secreted when there is an infection
Cysteine-rich, cationic molecule that binds to negative charges on bacterial membranes

12

How does the oral mucosa aid in ingestion?

Provides flexibility and a moist surface, making chewing and swallowing easier

13

Which is capable of more type sensation, oral mucosa, PDL, or pulp?

Oral mucosa

14

What types of fibers innervate pulp/dentin and what type of sensation do they provide?

C, A-delta, A-beta = mostly pain

15

What types of fibers innervate the PDL, and what type of sensation do they provide?

C and A-delta = pain
A-beta = proprioceptive

16

What types of fibers innervate the oral mucosa and what type of sensation do they provide?

A-beta = touch
A-delta and C = pain
A-delta and C = thermal
A-delta = taste

17

What type of cells are found in oral mucosa epithelium

Stratified Squamous epithelium

18

What occurs in the deep layers of the oral mucosa epithelium?

Location of cell division

19

What occurs at the superficial layers of oral epithelium?

This is where cells migrate, mature, become part of the surface, and then slough off

20

What is the turnover time for gingiva epithelium?

41-57 days

21

What is the turnover time for cheek epithelium?

25 days

22

What is the turnover time for taste buds?

10 days

23

What is the turnover time for junctional epithelium?

5-10 days

24

What is the cost/benefit of having fast turnover in epithelium

They can heal faster, but it also makes the tissues more vulnerable to conditions that affect cell division (chemotherapy, radiation, ulceration)

25

What are the most numerous cells of the oral mucosa?

Keratinocytes (aka epithelial cells)

26

What are the non-keratinocytes found in the oral mucosa?

Merkel cells
Melanocytes
Langerhans (dendritic cells)

27

Merkel cells

Sensory cells in the basal layer of the epithelium

28

Melanocytes

Pigment cells in the basal layer of the epithelium

29

Langerhans (dendritic) cells

Immune cells in the supra-basal layers

30

T/F - Different oral regions are lined by keratinized v non-keratinized epithelium

True

31

Describe keratinized epithelium

No organelles
Dehydrated
Tougher

32

Describe non-keratinized epithelium

Has organelles
Felixble

33

What do all epithelial cells/keratinocytes contain?

Cytokeratin

34

Cytokeratins

Large multigene family of proteins
Assemble into intermediate filaments to provide cytoskeletal support - mechanically tough

35

What are the two major groups of cytokeratines?

Type I (acidic)
Type II (basic)

36

Cytokeratin structure

Central helical core surrounded by non-helical ends
Each cell expresses at least 2 cytokeratins (one of each type)
They assemble into coiled heterodimers

37

What are the strongest cytokeratin structures?

Intermediate filaments

38

What are the intracellular components cytokeratins?

Desmosomes and Hemidesmosomes

39

What do keratin mutations create

Mutations to cytokeratins, which can lead to blistering in response to minor trauma

40

T/F - Different epithelial layers and tissues contain the same cytokeratins

False - Cytokeratins are characterisitic of the different layers and tissues

41

What can changes cytokeratin expression?

Cytokeratin expression can change with disease state
Mutations in cytokeratin genes can produce regionally specific diseases

42

Which is more permiable, keratinized or non-keratinized epithelium?

Non-keratinized

43

T/F - The amount of cytokeratin only increases in the supericial layers keratinized epithelium

False - The amount of cytokeratin increases towards the superficial layers of both types of epithelium

44

What are the biochemical properties of Keratinized cytokeratins

They promote aggregations
They promote binding to another molecule (fillagrin)

45

Describe the superficial layers of Keratinized epithelium

Very flat cells
Dehydrated
No organelles
Packed with cytokeratin and fillagrin complexes

46

What are the biochemical properties of non-keratinized cytokeratins?

Do not promote aggregation
Can't complex with fillagrin

47

Describe the superficial layers of non-keratinized epithelium

Cells are not flat or dehydrated
Retain nuclei
Cytokeratin tonofilaments

48

T/F - The permiability differences between keratinized and non-keratinized are due to cytokeratins

False - desmosomes contribute and are somewhat more numerous in keratinized epithelium

49

Membrane coating granules

Membrane bound organelles in the cell, filled with glycoproteins
1st appear in upper prickle layer
Released in more superficial layers to coat the cell
Found in both keratinized and non-keratinized cells to serve as an intercellular barrier to aqueous substances (more effective in keratinized)

50

Describe Membrane thickening

Envelope of 15nm cross-linked protein sheath comprised of loricrin and other proteins
Impermiable
On the inner face of keratinocytes in the upper layers of both types of epithelium

51

What takes up the most volume of the lamina propria?

ECM

52

What cells are present in the lamina propria

Fibroblasts
Macrophages
Mast cells
Other inflammatory cells

53

What makes up the ECM of the lamina propria

PGs, and PAGs
Glycoproteins (fibronectin)
Collagen (types I and III)
Elastin

54

Describe the epithelial/connective tissue interface

Scalloped
-has epithelial rete pegs, connective tissue papillae, and paipillary and reticular layers

55

Lining mucosa epithelium type

Non-keratinized

56

Describe the thickness of the epithelium in the buccal mucosa v the floor of the mouth

Buccal = thick (.5mm)
Floor of mouth = thin (.1mm)

57

Clinical implications of lining mucosa

Incisions more likely to gape and need to be sutured
Injections are less painful

58

Masticatory mucosa epithelium type

Keratinized

59

T/F - Lining epithelium has submucosa

True - it usually does

60

T/F - Masticatory mucosa has submucosa

False - it varies, but usually only in the hard palate

61

Clinical implications of the masticatory mucosa

Incisions don't gape and may not require suturing
Injections are more painful

62

What are the three areas of the lip region?

Exterior skin
Vermillion zone
Labial mucosa

63

Exterior skin of lip

Keratinized
Thinnest
Sweat glands
Hair follicles

64

Vermillion zone

Keratinized
Thin
Blood vessels close to surface
No sweat or mucous glands

65

Labial mucosa

Non-keratinized
Thicker
Mucous glands

66

Sulcular epithelium

Part of free gingiva, which faces the tooth
Gernerally not keratinized

67

Junctional epithelium

Forms a ceal around the tooth
Oriented along the long axis of the tooth
Highly permiable

68

What are the 2 basal lamina of the junctional epithelium

External (JE/lamina propria)
Internal (JE/tooth)

69

What supplies vasculature for the maxilla?

Superior alveolar and palatine arteries

70

What supplies vasculature for the mandible?

Inferior alveolar a
Buccal a
Mental a
Sublingual aa

71

What are the 3 routes blood can reach its destination in a tooth?

PDL
Interdentinal septa
Oral mucosa