An overview of the oral mucosa Flashcards
Define what the oral mucosa is Comprehend the functions of oral mucosal Describe the main structure of the oral mucosa Recognise the different types of oral mucosa and their regional and junctional variations
what structures are included in the oral mucosa
upper lip alveolar mucosa hard palate soft palate cheek dorsal surface of the tongue gingiva floor of mouth lower lip
what is the oral mucosa
the moist lining that covers the whole of the oral cavity
what are the differences between the oral mucosa and skin
the colour- oral mucosa lighter- the skin has keratin which is thicker and doesn’t allow blood vessels to show through as much
moisture- oral mucosa has a constant moist surface due to secretion of saliva
appendages- mucosa doesn’t have hair follicles sweat and sebaceous glands
what mechanical challenges does the oral mucosa face
chewing
what are the functions of the oral mucosa
protection sensation secretion absorption thermal regulation( in dogs) not humans
what does saliva contain
antimicrobial peptides which help battle invading microbes that enter
what does the oral mucosa protect against
mechanical
abrasive
microbial threats
what sensations can be felt in the oral mucosa
touch
temperature
taste
thirst and pain
what can be absorbed in the oral mucosa
sublingual dissolving drugs
what function occurs in dogs but not humans
thermal regulation- as dogs pant when they are too hot
what drug is used sublingually during angina attacks
GTN spray- glyceryl trinitrite spray 3x sprays sublingually
what re the types of oral mucosa
masticatory mucosa
lining mucosa
specialised mucosa
describe masticatory mucosa
areas that are subject to more mastication
more highly keratinised
describe lining mucosa
lines areas that are less subject to masticatory forces and the surface of these is less keratinised
describe specialised mucosa
subject to masticatory forces so has some keratin but has specialised tissue and structures related to taste eg the upper surface of the tongue
where is masticatory mucosa found
on the surface of the gingiva
hard palette
stiffer tissues
where can the lining mucosa be found
on the vermillion border the lining of the cheek lining of the lips floor of the mouth ventral surface of the tongue
when might the lining mucosa suffer from masticatory forces
due to malocclusion
what are the different types of papilla from anterior to posterior of the tongue
filiform papilla
fungiform papilla
circumvallate papilla
foliate papilla
describe the anterior 2/3 rds of the tongue
keratinised mucosa with specialised structures called papilla which hold tastebuds
describer the posterior 1/3 rd of the tongue
filled with lymphoid tissue and called the lingual tonsil
what is the main tissue component of the oral mucosa
epithelium lamina propia submucosa periosteum bone
what two parts make up connective tissue
lamina propia
submucosa
what is epithelial tissue
can be formed from ectoderm mesoderm or endoderm- closely packed layer of cells which line a cavity or hollow organ or body surface
what are the types of epithelial tissue
simple squamous simple cuboidal simple columnar transitional pseudo stratified columnar stratified cuboidal stratified squamous
what are the two major types of epithelial cells
simple cells- one layer of cells
stratified cells- multilayer of cells
what cells is the oral mucosa covered by
stratified squamous epithelium
what are the types of attachments between cells
tight junctions adherens junctions gap junction hemidesmosomes desmosomes
what is the desmosome
thickening plaques of the cell membrane which contains transmembrane filaments which contains cadherin protein
what protein is found in desmosomes
cadherin
describer the tight junction
specialised protein structure and tightens the gap between cells and prevents leakage and has selective permeable functions
hold adjacent epithelial structures together
describe the hemidesmosome
thickening plaques of the cell membrane which contains transmembrane filaments allows the cells to be tightly attached to the underlying basal lamina membrane and the ECM
what is the difference between keratinised and non keratinised
keratinsed- doesn’t look like cells as it is a protein and forms a thick layer on top of the cells
non keratinised- thicker and formed of more layers of cells due to the fact has to resist masticatory forces
what are the cellular components of the oral epithelium
keratinocytes and non keratinocytes
describer keratinocytes
those cells of keratinised and non keratinised epithelium
give examples of non keratinocytes
melanocytes
langerhans cell
merkels cells
and inflammatory cells
what is the difference between the prickle cell layer in keratinised cells and non keratinised cells
in keratinised- has more tonobrils and
what is found in the granular cell layer
keratohyaline granules- precursor of keratin
what is the order of layers of cells in keratinocytes (keratinised)
keratinised surface layer
granular intermediate layer
prickle cell layer
basal cell
what is the order of layers of cells in keratinocytes (non keratinised)
surface layer
intermediate layer- doesn’t contain granules of keratohyaline so it is not granulated intermediate
prickle cell layer
basal layer
what are the different levels of keratin maturation
ortho keratin- no nuclei in superficial layer
par keratin- remnants in the super facial layer
non keratinised- nuclei in the superficial layer
what is completely matured keratin called
ortho keratin
where are langerhans cells found
in the prickle cell layer of non keratinised cells
where are merkel cells found
in the basal layer of non keratinised cells
where are melanocytes found
in the basal layer of non keratinised cells
give examples of dendritic cells
langerhans cells
merkel cells
melanocyte cells
what do langerhans cell do
immune/defence: antigen presentation
what do melanocytes do
pigmentation:synthesis of melanin
what do merkel cells do
sensory: tactile sensation
what is the lamina propria formed of
the papillary layer and the reticular layer
describe the cells the lamina propria is made out of
fibroblasts endothelial cells inflammatory cells: macrophages mast cells lymphocytes
what are mast cells called before activation
histolytic cells- develop pseudopodia which helps them move around and surround bacteria and engulf via endocytosis
what is the structure of the lamina propria
fibres
ECM- contains glycoproteins and proteoglycans
blood supply
nerve supply
what fibres is the lamina propria made from
collagen type 1
collagen type 3
2% non collagenous fibres( elastin oxytalan)
what percentage of type 1 fibre collagen is the lamina propria made from
90%
what percentage of type 3 fibre collagen is the lamina propria made from
8%
what is the basal layer made from
the lamina lucida first then
the lamina densa
what connects the epithelial cell to the basal layer
the hemidesmosomes which are connected to the lamina lucida and densa and an anchoring fibril is connected to the connective tissue
what are the anchoring fibres made from
collagen type 6
what structures are found in the submucosa
gland
nerves
artery
vein
describe the filiform papilla
pyramidal and are highly keratinised cover almost all surfaces of the tongue
no tastebuds
what condition can be seen which involves the filiform papilla
the papilla can become overgrown and overkeratinisation this in turn can cause a hairy tongue (harbours bacteria and fungi)
describe fungiform papilla
look like a mushroom shape
contain tastebuds
describe the foliate papilla
they are leaf shaped
describe the pathway of taste buds
Taste buds detect chemicals dissolved in saliva from food in the mouth and throat. Then, these taste buds send their sensory information through neurons to the gustatory centre of the brain.
what are the different junctions in the oral mucosa
mucocutaneous
mucodental
mucogingival
