Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IOE > Oral mucosa > Flashcards

Oral mucosa Flashcards

1
Q

what is oral mucosa

A
  • membrane covering entirety of the oral cavity

- vast tissue with regional variations but common structural component present in all regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

where can oral mucous membrane be found

A 
upper + lower lips
gingiva
floor of mouth
dorsal surface of tongue
hard palate
cheeks (buccal mucosa)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are 3 differences between mucosa and skin

A

1) COLOUR
- skin pigmented according to our colour
mucosa is lighter + almost always pink (except some dark skinned individuals = blackish tinge on mucosa)

2) MOISTURE
mucosa moist all time due to minory salivary gland secreting saliva continously
it can be dry but always little bit of moisture + viscous thin layer over it
skin is always dry except for sweating

3) APPENDAGES
no skin appendages in mucosa (ie hair follicles, nails, sweat + sebaceous glands)
minimal fat secretion from sebaceous glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

mucous membrane forming the lips is called…

A

VERMILION BORDER

interface between skin + oral mucosa at edge of lips

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens from the oesophagus down

A

different type of tissue (STILL mucous membrane)
continuous with the oral cavity
so continuation between lining of the oral cavity and lining of the gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what 5 functions does oral mucosa have

A

1) protection
2) sensation
3) secretion
4) absorption
5) thermal regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

explain the protective function of mucosa

A
  • protects against continuous mechanical stimulation in mouth (by mastication/chewing) that can harm tissues underlying oral mucosa
  • protects against harmful chemicals that enter the mouth
  • antimicrobial activities (saliva contains anti-microbial peptides and secretions from the gingival sulcus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

explain the sensation function of mucosa

A
  • neuroreceptors are embedded under it (sensitive to touch, pain, temperature)
  • tastebuds embedded in tongue, throat, palate help taste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

explain the secretion function of mucosa

A
  • hundreds of minor salivary glands embedded in it continuously secrete saliva
  • limited sebaceous glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

explain the absorption function of mucosa

A

floor of mouth + oral mucous membrane in certain areas have high absorptive rate SO can absord medication + release it into blood stream quickly
(ie sublingual tablets / sublingual dissolving drugs for aschemic heart disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

explain the thermal regulation function of mucosa

A

happens in animals (ie dogs) NOT humans

when they pant, the tongue is outside the mouth so saliva evaporates to regulate their body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the 3 main types of mucosa

A

1) masticatory
2) lining
3) specialised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where and what is masticatory mucosa

A
  • gingiva and hard palate
  • little bit on tongue
  • KERATINISED = has an extra protective layer (keratin) which helps protect mucous membrane and underlying structures from masticatory forces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where and what is lining mucosa

A
  • lips (labial mucosa), cheeks (buccal mucosa), floor of mouth, inferior surface of tongue
  • NON-KERATINISED = bc not subject to masticatory forces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where and what is specialised mucosa

A
  • dorsal surface of the tongue
  • anterior 2/3 = covered by (masticatory mucosa made of) specialised mucosa because it is keratinised to protect against masticatory forces + contains specialised complex structures (TONGUE PAPILLAE)
  • posterior 1/3 = still covered with oral mucosa but full of lymphoid tissue and lingual tonsils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what functions can tongue papillae have

A
  • some have mechanical functions

- some have sensory functions (contain tastebuds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the 3 main tissue components of the oral mucosa

A

1 - top) covering epithelial tissue
2 - middle) supportive lamina propria / connective tissue support
3 - bottom) submucosa (absent at certain sites)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is epithelial tissue

A
  • close packed cell layers covering a surface or lining a cavity / hollow organ
  • can be either…
  • SIMPLE = 1 layer of epithelial tissue
  • STRATIFIED = multiple layers
  • then further classified according to their shape into squamous, cuboidal, columnar, transitional
    (ie simple squamous, stratified cuboidal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which 4 types of connections can occur between epithelial cells to connect them together so tightly

A

1) GAP JUNCTION
has some cytoskeleton filaments across it so can see intercellular space but the cells are still connected = narrow gap between 2 adjacent cells

2) ADHERENS JUNCTION
anchoring junctions, hold epithelial cells together made of a certain transmembranous protein help cells attach to each other (CADHERINS)

3) TIGHT JUNCTION
also formed by cadherins, 2cells v tightly connected together

4) DESMOSOME
formed by thickening of cell membrane on each side of the cell, tonofilaments made from the cadherin protein lodge themselves into plaque thickenings and connect the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what connects basal surface of epithelial cells to their underlying basement membrane / basal lamina

A

hemidesmosomes

do this via intermediate filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is oral mucous epithelium made of

A
  • stratified squamous epithlium
  • top section = squamous so desquaming (constantly renewing, regenerated and replaced + surface always removed due to friction inside the oral cavity)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the 2 types of stratified squamous epithelium, explain these

A

1) keratinised
covers masticatory mucosa + dorsum of tongue
keratin in oral cavity is softer and called the cornified layer / stratum corneum

2) non-keratinised
lining mucosa
why ulcers form easily on inside or lip / cheek (hard to get ulcer on masticatory surfaces + painful as have scraped a tightly attached surface)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are the 2 major types of cells found in the oral epithelium

A

1) keratinocytes
- cells of keratinised and non keratinised epithelium
- form majority of layers of epithelium coverage of the oral mucosa
- contain CYTOKERATINES
- form / synthesise keratin
2) non-keratinocytes
- few in number
- present in epithelium
- specialised functions
- ie melanocytes, langerhans cell, merkel’s cell, inflammatory cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

so what is epithelium formed mainly of

A
  • keratinocytes

- a few non-keratinocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

name the 4 layers in keratinised epithelium (bottom to top)

A

1) basal layer / germanative cell layer
2) prickle cell layer / spinous cell layer
3) granular intermediate layer
4) keratinised surface layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

name the 4 layers in non-keratinised epithelium (bottom to top)

A

1) basal layer / germanative cell layer
2) prickle cell layer / spinous cell layer
3) intermediate layer (NOT granular because dont have granules of keratin)
4) surface layer (no keratin, hyalokeratin granules or formation of keratin barrier)

27
Q

describe the basal cell layer of epithelium

A
  • SMALLER in non-keratinised
  • basal cells = cuboidal
  • known as germanative cell layer as basal cells = mainly made of stem/progenitor cells which mainly do mitosis (responsible for regenerating all cell layers of epithelium)
  • when something is desquamated basal layer divides to replace it with 1 new cell remaining as a stem cell + 1 differentiating into required epithelial cell
28
Q

describe the prickle/spinous cell layer of epithelium

A
  • under microscope these cells shrink when prepared for histology making desmosomes (cellular attachments) appear MORE apparent with spine like prickles
  • in keratinised = bundles of tonofilaments + tonofibres / tonofibrils
  • non-keratinised = dispersed tonofilaments + tonofibres, not as electron dense on TEM (cant see tonofibres in non-kerat)
29
Q

describe the granular intermediate cell layer of keratinised epithelium

A
  • more tonofibres + KERATOHYALINE / HYALOKERATIN granular bodies (prelude of keratin protein)
30
Q

describe the keratinised surface layer of keratinised epithelium

A
  • final layer
  • cell layers are filled with keratin SO the organelles start shrinking until the cell is completely keratinised
  • at this layer the cell loses ALL organelles becoming dead and part of this keratin layer which forms a barrier on top of the epithelium
  • proliferation + maturation stages
31
Q

describe the intermediate layers of non-keratinised epithelium

A
  • have membrane coated bodies and glycogen
32
Q

describe the surface layer of non-keratinised epithelium

A
  • as cells mature they have LESS cell organelles BUT retain nucleus and some others
  • no keratin, no hyalokeratin granules, no formation of keratin barrier
  • cells organelles and nucleus = retained and afterwards desquamated
33
Q

what 2 levels of keratinisation can be present within keratinised epithelium in the oral cavity

A

1) para-keratin
- cells retain small nuclei + are present in middle of keratinised layer
2) ortho-keratin
- completely keratinised layer
- NO nuclei

+ non-keratinised

  • thicker
  • higher in number of layers (no keratin to protect so compensated for by this)
34
Q

list the 3 main types on non-keratinocytes

A

1) melanocytes
2) merkel cells
3) langerhans cells
lymphocytes + dendritic except merkel

35
Q

explain the location and function of

a) melanocytes
b) merkel cells
c) langerhans cells

A

a) basal cell layer of stratified epithelium
PIGMENTATION = synthesise melanin (have melanin granules in them + are more active in people of darker skin where melanin is secreted w/in the epithelium to give the gingiva + palate a darker colour)

b) basal layer which is connected to lamina propria by the MERKEL SENSORY DISK (connected to a nerve)
SENSORY = tactile sensation bc connected to a sensory neurone + merkel tactile disk

c) super basal layers
IMMUNE / DEFENSE = antigen presenting

36
Q

what is the lamina propria

A

loose connective tissue forms a papillary layer underneath the epithelium in the form of

1) interdigitation
2) invaginations of connective tissue into the epithelium

37
Q

why is the top layer of lamina propria called the papillary layer

A

the invaginations are called papillae (connective tissue papillae)
in the opposite side the epithelium forms invaginations inside of the connective tissue called Epithelial Rete Pegs / Ridges

38
Q

what is the bottom layer of lamina propria called, describe this

A

the reticular layer

  • more dense
  • full of fibres
39
Q

what are the 3 components of the lamina propria

A

1) cells
2) fibres
3) extracellular matrix

40
Q

which 5 types of cells make up the lamina propria

A

1) fibroblasts (most predominant cells)
2) endothelial cells
inflammatory cells:
3) macrophages
4) mast cells
5) lymphocytes

41
Q

what is the role of fibroblasts

A

synthesise extracellular matrix and fibres (mainly collagen)

42
Q

what is the role of macrophages

A
  • called HISTOCYTES (+ similar shape to fibroblasts) prior to activation
  • engulf foreign bodies
  • antigen presenting
  • have
    1) pseudopodia (fake feet) = allows them to move + trap bacteria / foreign bodies
    2) lysosomes containing lysozymes = kill foreign bodies
43
Q

what is the role of mast cells

A
  • responsible for cell mediated immunity (inflammatory cells)
  • ie anaphylaxis hypersensitivity from food - reaction starts in oral cavity
  • have
    1) deep blue granules = hold histamine (ie released in hayfever) + heparin
44
Q

what is the role of lymphocytes

A
  • few in number in lamina propria BUT increase during inflammation / infection
  • large round cells with large nucleus
45
Q

what fibres are found in the lamina propria and in what proportions

A

collagen type I = 90%
collagen type III = 8%
non-collagenous fibres = 2% (elastin, oxytalan)

46
Q

what is the extracellular matrix of the lamina propria

A
  • gel holding cells + fibres together

- made of glycoproteins + proteoglycans

47
Q

why are blood and sensory nerve supplies present in the lamina propria

A
  • lamina propria
    a) functions as a mechanical support for epithelial tissue
    b) allows nutrients into epithelial tissue, vascularisation + innervation
48
Q

what is the basal lamina

A

interface of connective tissue

49
Q

what structures are present in the basal lamina

A 
on surface (part of lamina propria)
1) hemidesmosomes
2) tonofilaments
2nd layer (part of epithelial tissue)
1) lamina lucida (transparent layer)
3rd layer (part of epithelial tissue)
1) lamina densa
bottom layer
1) anchoring fibrils
2) collagen fibrils
50
Q

what do the hemidesmosomes do

A
  • connect basement membrane to the lamina propria

- only thickening of cytoplasmic membrane of bottom parts of the cells and tonofilaments (extend into lamina lucida)

51
Q

what is the lamina densa

A
  • collagen fibres from lamina propria form loops of fibres that attach basement membrane to connective tissue, lamina propria + hemidesmosomes
  • loops = made from collagen type 6 + interwound with them are collagen types 1+3
52
Q

what happens when there is defect of deficiency in the basement membrane / basal lamina

A

disease and pathologies characterised by immune deficiency

ie cancer - invasion of epithelium into the connective tissue

53
Q

what is the submucosa

A
  • last part of main structure of oral mucosa

- present in almost all mucosal tissue

54
Q

what structures are present in the submucosa

A
  • connective tissue containing
    1) fibres
    2) blood vessels
    3) nerves
    4) minor salivary glands
    5) sebaceous glands (labial + buccal mucosa only)
55
Q

what are the submucosal sebaceous glands called

A

fordyce nodules / fordyce spots

56
Q

what complex and specialised structures does the specialised, keratinised mucosa covering the dorsal surface of the tongue contain and what do they do

A

LINGUAL PAPILLAE

some have tastebuds = perceive taste sensation

57
Q

what are the 4 types of tongue papillae, explain these

A

1) FILIFORM
- form major part of interior surface of tongue
- completely keratinised
- pyramidal shape
- NOT squamed regularly
- mainly mechanical + protective function
2) FUNGIFORM
- look like mushrooms
- embedded between filiform papillae
- keratinised
- appear pink as highly vascularised
- contain tastebuds
3) FOLIATE
- square / leaf shape
- tastebuds on their sides
- non-keratinised epithelium
4) CIRCUMVALLATE
- lot of tastebuds on sides
- has the opening of minor salivary glands (glands of Ebner)

58
Q

what is the outcome of filiform papillae not being squamed regularly in some disease

A

they overgrow
form the ‘hairy tongue’
tongue becomes black due to keratin on its surface

59
Q

describe the tastebuds

A
  • onion shape
  • present in tongue papillae + soft palate (between soft + hard)
  • perceive taste - sends sensation to brain via an AFFerent nerve in the submucosa
60
Q

which 3 junctions are present in the oral mucosa

A
  • mucocutaneous
  • mucodental
  • mucogingival
    theres always an intermediate layer in between junctions
61
Q

explain the mucocutaneous junction

A
  • between the vermillion border of lip and epithelium of labial lining
  • vermillion border and skin = both keratinised BUT different forms of keratin
  • merge into non-keratinised epithelium covering labial lining mucosa
62
Q

explain the mucodental junction

A
  • formed of connection between gingiva and tooth
63
Q

explain the mucogingival junction

A

junction between gingiva (orthokeratinised) and mucosa that covers the alveolar bone (nuclei in surface layers, non keratinised)

IOE (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions