Histology Of Nasal And Oral Cavities Flashcards
What is the histology and hallmarks of the:
Respiratory Epithelium?
Pseudostratified columnar ciliated epithelium
With lamina propria
- cilia
- goblet cells
- thick b.m.
What is a “lamina propria”?
Found in respiratory epithelium, lingual papilla, and oral mucosa
Rich, vascular network of complex set of capillary loops
What are the 3 regions of the nasal cavity?
Nasal vestibule
Respiratory region
Olfactory region
What is the nasal cavity divided by?
Nasal septum
What is the histology and hallmarks of the:
Nasal vestibule
Keratinized stratified squamous epithelium
Inside nostrils, lined by skin
What is the histology and hallmarks of the:
Respiratory region
Pseduostratified columnar ciliary epithelium
Inferior 2/3 of nasal cavities and is lined with respiratory mucosa
What is the histology and hallmarks of the:
Olfactory region
Pseudostratified ciliated columnar epithelium
Thick
Thin b.m.
No goblet cells (NONE NONE NONE)
Located at apex and lined w/ specialized olfactory mucosa
What is the function of the nasal cavity?
Adjust temperature and humidity of inspired air
What are the Paranasal sinuses?
What are the lined with?
Air filled spaces in bones of the walls of the nasal cavity;
An extension of the respiratory region of the nasal cavity
Respiratory epithelium (pseudostratified columnar ciliated epithelium)
How do the sinuses communicate w/ nasal cavities?
Tru narrow opening onto respiratory mucosa via ciliary movements
What are sinuses subject to ?
Subj. to acute infection after viral infection of UR tract
What is the oral cavity lined with?
Protective mucous membrane - oral mucosa
What is the histology and hallmarks of the:
Oral mucosa
Stratified squamous w/ varying keratinization
3 divisions: lining, masticatory, specialized mucosa
What is the oral mucosa supported by? And what is that composed of?
Supported by dense collagenous tissue (lamina propria)
CT composed of Fibroblasts, WBCs, Collagen fibers
What are the two layers of CT for oral mucus a?
Papillary layer
Dense layer
What is the Papillary layer of oral mucosa CT composed of?
Superficial, loose CT
W/ NV
What is the Dense layer of oral mucosa CT composed of?
Deep, dense, irregular CT w/ large amts. of fibers
What is the function of Rete Ridges ?
Keep underlying mucosa attached in oral cavity
What is the submucosal layer composed of? When is it present?
Present depending on location (cheeks)
Loose ct, adipose tissue, salivary glands
What is the histology and hallmarks and location of the:
Masticatory Mucosa
Keratinized and/or parakeratinized stratified squamous epithelium
On hard palate, gingival, and dorsal surface of tongue
Superficial cells will still have highly condensed nuclei that will remain until the cell is exfoliated
Highly intergitiated with Rete ridges and papillae
Thin or absent submucosa (no fat on hard palate)
What is the histology and hallmarks and location of the:
Lining Mucosa
NON keratinized stratified squamous epithelium
Inner lip, cheeks, alveolar mucosal surface, floor of mouth, inferior surface of tongue,
Soft palate
Few Rete ridges and ct papillae
Has DISTINCT submucosa
Thicker than keratinized
Has 3 layers (stratum basale, stratum spinosum, stratum superficiale)
What are the 3 layers of lining mucosa?
Stratum basale - singly layer of cells on basal lamina (deepest)
Stratum spinosum - several cells thick
Stratum superficiale - most superficial layer
What is the histology and hallmarks and location of the:
Specialized mucosa
Specialized assoc. with taste
Tongue: keratinized stratified squamous
Lingual papillae: keratinized epithelium w/ lamina propria
Only on dorsal surface of tongue
What two layers of mucosa does the dorsal surface of the tongue have?
What does it contain?
Masticatory mucosa
Specialized mucosa
Covers the muscular surface
Contains lingual papillae and taste buds
What are lingual papillae?
Small elevated structures of specialized mucosa; some assoc. w/ taste buds
Keratinized epithelium w/ lamina propria
What are the different types of papillae?
Filiform
Foliate
Fungiform
Circumvallate
What are the characteristics of the
Filiform papillae
Move food toward pharynx to swallow
Gives tongue velvet texture, most widespread
Shaped like a FINE POINTED CONE
NO TASTE BUDS
What are the characteristics of the
Foliate Papillae?
Vertical ridges on lateral tongue surface
Rect. Shape
Have TASTE
What are the characteristics of the
Fungiform papillae
On dorsal surface of tongue in lesser #s
Provide TASTE
Look like little rounded cone
What are the characteristics of the
Circumvallate papillae
Only 7-15 of them in front of sulcus terminalis
Raised mushroom shaped structures
W/ sunken appearance
100s of TASTE buds present
What is the basic structure of a taste bud?
Barrel shaped organs that perceive food molecules composed of 30-80 spindle shaped cells extending from b.m.
What are the 5 taste sensations provided by taste buds?
Sweet Salty Sour/acidic Bitter Umami
Besides the tongue, where else could you find taste buds?
Palatoglossus arch
Soft palate
Posterior surface of epiglottis
Posterior wall of pharynx
What are neuroepithelial (sensory) cells?
What do they synapse w?
Elongated cells that extend from basal lamina of epithelium to taste pore
Extend microvilli thru pore
Synapse w/ afferent sensory neurons of CN 7,9, 10
What are supporting cells of taste buds?
What do they synapse with?
Elongated cells extending from basal lamina to taste pore
Contain microvilli on apical surface
DO NOT SYNAPSE w/ N. CELLS
What are basal cells of taste buds?
Small cell near basal portion of taste bud near basal lamina
Stem cells for two other cells types (supporting and neuroepithelial)
Which tonsil is located in the Oropharynx?
Palatine tonsil
Which tonsil is located in the Nasopharynx?
Pharyngeal tonsil
What is the histology and hallmarks of the
palatine tonsils?
NON-keratinized stratified squamous epithelium
Has 1020 tonsillar crypts (deep invaginations)
Epithelial lining densely populated w/ lymphocytes (spherical, for viral and fungal)
Has dense CT acting as partial capsule
What is the histology and hallmarks of the and location
Pharyngeal tonsil?
Pseudostratified columnar ciliated epithelium
On posterior wall of nasopharynx
NO CRYPTS (but invaginated mucosa w/ shallow infolding), thin capsule
What is the histology and hallmarks of the and location
Lingual tonsil?
Stratified squamous epithelium
Along base of tongue
Has terminal centers, varying # of crypts, NO CAPSULE
What is the crown of a tooth?
What protects it?
Projects into oral cavity
Protected by enamel
What is the root of a tooth?
What invests into it?
Embedded in alveolar ridge of alveolus
Invested by thin layer of cementum
What is the bulk of a tooth composed of?
Dentin
What does dentin enclose?
What is dentin?
What are dentinal tubules?
Central pulp chamber
Calcified organic matrix w/ calcium hydroxyapatite crystals
Parallel tubes that go to edge of dentin
What is enamel composed of?
parallel enamel rods (prisms) of calcium hydroxyapatite
How are rods(prisms) of enamel held together?
Cemented together by calcified inter prismatic material
What do the diagonal lines that cross enamel represent?
Incremental growth lines
Why is enamel so much harder than bone?
Greater ratio of calcium hydroxyapatite
What produces Dentin?
Odontoblast
What produces enamel?
Ameloblast
What is cementum?
What does it do?
Amorphous calcified tissue at base of tooth, covering dentin of root
Anchors Peridontal ligament
What composes pulp?
Characteristics?
Function?
Loose, mesenchymal CT w/ collagen fibers, fibroblasts, mesenchymal stem cells
Highly vascular, well innervated
Provides nutrition to dentin and can form reactive dentin upon injury
If a tooth is “dead” what is damaged?
Pulp
How is a tooth anchored in alveolar bone?
Anchored via cementum and periodontal ligament
Where does the periodontal ligament insert? What is it composed of?
Inserts into cementum and alveolar bone
Composed of collagen fibers
What does the periodontium consist of? what is it basically?
Cementum
Periodontal L.
Alveolar bone
Gingival
Where teeth are anchored
How do you lose a tooth?
Osteoblasts chew up periodontal L.
