Oral Mucosa I&II Flashcards
what is the oral mucosa
soft tissue lining the oral cavity
what are the main components of oral mucosa
epithelium and ct
where does oral mucosa extend from and to
vermillion border to fauces (oropharyngeal isthmus)
what type of surfaces does oral mucosa line
wet surfaces of oral cavity
clinical features of oral mucosa
- smooth in most areas
-stippled gingiva (attached gingiva stippled due to its firm attachment to underlying bone)
-papillated tongue (dorsum is papillated housing taste buds and providing texture
-ridged hard palate
-moist due to minor salivary glands
-pink / red depending on blood supply and keratinization (ex the red has high blood supply and few collagen fibers and pink opp)
-variable thickness
-fixed( attached to bone ex. gingiva) and mobile (not attached to bone ex. soft palate)
what are the functions of oral mucosa
-protection
-sensation
- secretion
-immune
how does oral mucosa protect
acts as a barrier between underlying tissue and external environment protecting against mechanical forces, abrasion, heat, water loss and microorganisms
how does oral mucosa sense
contains nerve endings that detect temperature, touch , thirst and we have receptors helps with reflexes like swallowing, gagging, and salivation
how is the oral mucosa always moist
due to minor salivary glands which continuously release mucus and saliva
also we have sebaceous gland eg fordyceβs spots
how does oral mucosa fight infections
contains immune cells in epithelium and CT
what is a fordyceβs spots
pale yellow spots that are normal variation found in lip, buccal mucosa and tonsillar pillar
what are types of oral mucosa
-lining mucosa
-masticatory mucosa
-specialized mucosa
Lining Mucosa
- flexible , nonkeratinized
- areas where there is no mastication
-in inner lip and cheek, ventral surface of tongue, soft palate
Masticatory Mucosa
- tough, keratinized
- in areas exposed to mechanical stress
- in hard palate and gingiva
Specialized Mucosa
in dorsum of tongue and rest is lining mucosa
where is lining mucosa found
lining the oral cavity where flexibility and movement is required
what type of epithelium is lining mucosa
stratified squamous nonkeratinized
which mucosa has the epithelium thicker
A- lining
B- masticatory
A- lining mucosa
describe the epithelial CT junction of lining mucosa
connective tissue papillae are slender and extend only slightly into the epithelium because the rete pegs are not very deep so this creates a smoother interface compared to masticatory mucosa
whatβs a lamina propria
connective tissue layer beneath the epithelium of the oral mucosa
in the lining mucosa the lamina propria has beneath it what
submucosa making the mucosa more flexible and movable (not tightly attached to bone)!!!!
in the masticatory mucosa the lamina propria has beneath it what
bone without a submucosa this makes the mucosa firm and immovable
lamina propria is thicker in
A-lining
B- masticatory
A- lining
where is masticatory mucosa found
regions of mouth where we have compressive and shear forces as we said like hard palate and gingiva
describe the epithelial CT junction of masticatory mucosa
highly folded with deep interdigitating rete pegs and connective tissue papillae. providing mechanical strength to resist friction and forces from chewing
what type of epithelium does the masticatory mucosa have
stratified squamous Para keratinized
describe the lamina propria in masticatory mucosa
thick but not as lining and it has large collagen bundles
why is the specialized mucosa named that
because it has taste buds
what kind of epithelium does the specialized mucosa have
stratified squamous parakeratinized
what structure is found in the specialized mucosa
lingual papillae which includes both sensory and mechanical functions
the epithelium of lining mucosa has 3 layers
1- stratum basal
2- stratum spinosum
3-startum superficial
stratum basal
-cuboidal cells
-nuclie oval
-sets on BM
-cells are attached to BM by hemidesmosmes
stratum spinosum
contains keratinocytes connected by desmosomes, giving it a spiny appearance
what are Tonofilaments, and what is their role in the Stratum Spinosum
Tonofilaments are keratin intermediate filaments inside keratinocytes.
They extend toward desmosomes, helping to connect cells.
how does spinosum appear under LM
desmosomes appear as βpricklesβ between cells, giving the layer its spiny look.
how does spinosum appear under TEM
prickles are tonofilaments extending from the cells and attaching to desmosomes.
why spiny appearance
desmosomes holding cells together after shrinking during slide preparation
stratum superficial
-Cells are squamous (flat) and alive, containing nuclei.
-May have small, flattened nuclei but lacks a keratinized surface layer.
-Example: Buccal mucosa (lining mucosa) is non-keratinized.
list the epithelium layers of masticatory mucosa
1- startum basal (germinativum)
2- stratum spinosumI( prickle cell layer)
3- stratum granulosum
4-stratum superficial (parakeratinzed)
orthokeratinized
surface cells have lost nuclie and found in skin
parakeratinzed
cells retain dead nuclie and found in gingiva
what are the two layers of lamina propria
- papillary layer
- reticular layer
papillary layer
layer closet to epithelium and its between epithelial pegs (ridges) and it shows regional variation in mouth
loose arrangement of collagen fibers
reticular layer
between papillary layer and submucosa
got bundles of collagen fibers
submucosa
-its a fibrous CT
-some areas have loose submucosa others dense
-has minor salivary glands
-the collagen and elastic fibers attach it to the underlying bone or muscle
what type of epithelium is found in skin
keratinized squamous epithelium
what type of epithelium is found in the oral mucosa (lining of the lips)
nonkeratinized squamous epithelium
what kind of salivary glands we have in lips
minor mucoserous salivary gland
what does the skin of lip contain
sweat glands, sebaceous glands , hair follicles
what does the vermillion zone and labial mucosa contain
orbicularis oris muscle
which pharyngeal arches contribute to the development of the tongue
the tongue develops from arches 1, 3, and 4
Anterior 2/3 (body) β from 1st arch
Posterior 1/3 (base) β from 3rd and 4th arches
what kind of mucosa covers tongue
βοΈ Specialized mucosa (dorsal surface)
βοΈ Lining mucosa (ventral surface)
what divides the tongue into symmetrical halves
midline septum
which part of the tongue is flexible and responsible for movement
βοΈ Anterior 2/3 (body) β moves for speech, mastication, and swallowing
βοΈ Posterior 1/3 (base) β anchored to the pharynx, less mobile
which papillae contain taste buds
βοΈ Fungiform
βοΈ Foliate
βοΈ Circumvallate
β Filiform papillae do NOT contain taste buds (they provide friction for food handling)
tongue known as
flexible muscular structure
what functions do the tongueβs movements help with
βοΈ Suckling (infants)
βοΈ Mastication (chewing)
βοΈ Mixing food with saliva
βοΈ Positioning food between teeth
βοΈ Formation of food bolus
βοΈ Swallowing (oral phase)
βοΈ Cleansing oral vestibule & sulci
βοΈ Speech articulation
βοΈ Gagging / retching
what divides the dorsal surface of the tongue into anterior 2/3 and posterior 1/3
sulcus terminalis β a V-shaped groove
what are the functions of lingual papillae
βοΈ Mechanical function β Helps in food manipulation
βοΈ Sensory function β Contains taste buds (except filiform)
what structure is found in the posterior 1/3 of the tongue
lingual tonsil β extensive nodules of lymphoid tissue
which papillae have a mechanical function and do not contain taste buds
βοΈ Filiform papillae
located in dorsum anteriorly
White in color
Most numerous
Flame-shaped
Keratinized epithelium
Create a tough, rough surface
Which papillae are scattered anteriorly, smooth, and red
βοΈ Fungiform papillae
Smooth and rounded
Contain taste buds in their thin, non-keratinized epithelium
why do filiform papillae appear shorter than fungiform papillae in histological sections
Due to the plane of sectioning
location of fungiform papilla
between filiform papilla
most numerous near tip of tongue
why is fungiform papilla red
due to their highly vascular CT core
where are foliate papillae located
lateral border of tongue post appearing as parallel ridges
are foliate papillae well developed in humans
βοΈ No, they are poorly developed in humans but in animals its well developed
βοΈ Contain only a few taste buds
what is found near foliate papillae
lymphoid tissue
where are circumvallate papillae located
βοΈ Located in a V-shape at the posterior tongue
βοΈ 8-12 large, rounded structures
βοΈ Surrounded by a circular sulcus/groove
what type of epithelium is found on different parts of circumvallate papillae
βοΈ Oral surface β Keratinized
βοΈ Lateral/vertical surface (inside sulcus) β Non-keratinized (contains numerous taste buds)
what is the function of minor serous salivary glands near circumvallate papillae
Von Ebner glands which open into sulcus β Secrete serous fluid to wash away bitter taste
what is the shape of taste bud
onion
where are taste buds found
βοΈ Tongue
βοΈ Soft palate
βοΈ Other areas of the oral cavity & pharynx
what type of cells make up taste buds
βοΈ Taste cells (neuroepithelial cells)
βοΈ Basal (stem) cells
how many cells make up a taste bud
30-100 spindle-shaped cells in epithelium
what structures connect taste bud cells
Junctional complexes
what is a taste pore
apical tip of the taste bud that opens into the oral cavity
what kind of receptors are the taste buds
specialized chemoreceptors
what are the three types of cells in a taste bud
βοΈ Sensory cells β Detect taste and send signals to nerves
βοΈ Basal cells β Replace old taste bud cells
βοΈ Supporting cells β Provide structural support
how does taste sensation work
1οΈβ£ Food dissolves in saliva
2οΈβ£ Stimulates sensory cells in taste buds
3οΈβ£ Sensory cells release neurotransmitters
4οΈβ£ Signals travel via Cranial Nerves VII facial nerve, IX glosso , & X vagus to taste ganglia
5οΈβ£ Signals reach the brainstem β thalamus β cortex
what are the five basic taste sensations
βοΈ Sweet β Sugars & artificial sweeteners
βοΈ Sour β Acids (H+ ions)
βοΈ Salty β Sodium (Na+) & other salts
βοΈ Bitter β Alkaloids (e.g., caffeine, quinine)
βοΈ Umami β Glutamate (found in meat, cheese, MSG)
what are the 3 types of gingival epithelium
free gingival epithelium , attached gingiva , crevicular epithelium (junctional epithelium)
why is JE imp for gingival integrity
forms a seal between tooth and gingiva preventing bacterial invasion and maintaining tissues
what makes JE unique
its non keratinized , squamous cells stratified but thin, and soft tissue attached to hard tissue by hemidesmosomes
what is the role of hemidesmosomes
attach JE to basal lamina providing smooth junction between epithelium and lamina propria no invagination
JE rests on
basement membrane
can the junctional epithelium regenerate
yes, it can regenerate from adjacent oral epithelium when damaged
why is the junctional epithelium (JE) interface straight
lacks rete pegs because it does not experience masticatory forces
is the junctional epithelium involved in mastication
no, it is a delicate, non-keratinized epithelium attached to the tooth
is attached gingiva involved in mastication
yes , Para keratinized , thick and convoluted for better attachments
what makes the dentogingival junction a unique junction in the human body
only place where soft tissue (gingiva) attaches directly to a hard structure (tooth enamel/dentin/cementum)
how does dentogingival junction protect oral environment from body internal environment
provides a seal
why is the basal lamina in dentogingival junction atypical
because it attaches epithelium to hard tissue (tooth) using hemidesmosomes, making it easier to break
