Lecture 11: Histology of Nasal and Oral Cavities Flashcards
What are the hallmarks of respiratory epithelium?
- Ciliated
- Thick basement membrane
- Many goblet cells
Pseudostratified Columnar Ciliated Epithelium
What are three regions of the nasal cavities?
Nasal Vesituble: Nostril area
Respiratory Region: Inferior ⅔
Olfactory Region: Superior ⅓
What type of epithelium lines the nasal vestibule?
Keratinized stratified squamous epithelium
What are paranasal sinuses?
What is their clinical significance?
- Extensions of respiratory region of the nasal cavity
- Communicates with nasal cavities via narrow openings
- Subject to infections (URI)
What are the hallmarks of olfactory mucosa?
- Lacks Goblet Cells
- Dramatically thicker than respiratory epithelium
- Still pseudostratified ciliated columnar
- Thin Basement Membrane
What is the function of the olfactory glands?
Serous secretions that dissolve odorant molecules
Make up for lack of mucus from goblet cells
What cells have specialized, nonmotile cilia with odorant receptors?
Olfactory Receptor Cells
What type of epithelium is found in the oral cavity?
What are the three classifications of this epithelium?
Protective Mucous Membrane: Oral Mucosa
-
Stratified Squamous (w/ varying keratinization)
- Masticatory
- Lining
- Specialized Mucosa
What layer of mucosa in the oral cavity contains the neurovasculature?
Papillary Layer of Lamina Propria
If the submucosal layer is present in the oral cavity, what does it contain?
Loose CT
Adipose Tissue
Salivary glands
What epithelium makes up the masticatory mucosa?
Keratinized and/or parakeratinized stratified squamous epithelium
- Nuclei highly condensed
- Thin/absent submucosal layer*
Where can you find masticatory mucosa?
Hard palate
Gingiva
Dorsal surface of the tongue
What is the purpose of rete ridges and papillae in masticatory mucosa?
Allows mucosa to stay firmly adhered to connective tissue beneath it
Where is lining mucosa found?
- Lips
- Cheeks
- Alveolar mucosal surface: where teeth are fixed
- Floor of mouth
- Inferior surfaces of the tongue
- Soft palate
What type of oral mucosa would have a distinct submucosa?
Lining mucosa
What type of epithelium makes up lining mucosa?
Nonkeratinized stratified squamous, may be parakeratinized in some sections
Quite Thick
What are the 3 layers of the epithelium of lining mucosa?
- Stratum basale: single layer and regenerates cells
- Stratum spinosum: thick layer
- Stratum superficiale: surface cells
What sense is the oral specialized mucosa associated with?
Taste
Where is the oral specialized mucosa located?
Dorsal surface of the tongue
-contains papillae and taste buds
What type of epithelium makes up oral specialized mucosa?
Keratinized epithelium w/ lamina propria
What lingual papillae do not contain taste buds?
Filiform papillae
What is the function of the filiform papillae?
Move food towards pharynx for swallowing
Give dorsal surface of tongue velvety texture
No taste!
What structure is this?
Filiform papillae
Where are foliate papillae generally found on the tongue?
What does it do?
Posterior lateral regions
Provides taste sensation
What structure is this?
Foliate Papillae
Where are fungiform papillae generally found on the tongue?
What does it do?
Dorsal Surface
Provides taste sensation
What structure is this?
Fungiform Papillae
Where can circumvallate papillae be found?
- Few in number but has hundreds of taste buds
- Location restricted to the posterior part of tongue
What structure is this?
Circumvallate Papillae
Where else can taste buds be found that is not part of the tongue?
Mucosa
- Glossopalatine arch
- Soft palate
- Posterior surface of epiglottis
- Posterior wall of pharynx
What is the role of neuroepithelial cells in the taste buds?
- Elongated cells extending from basal lamina of epithelium to the taste pore
- Synapse with afferent sensory neurons of CN VII, IX, or X
What structure is this?
Taste bud
What are tonsils and where are they found?
Large lymphoid tissue that protects against inhaled or ingested substances
Found in: mucosa of posterior oral cavity, oropharynx, and nasopharynx
What type of epithelium is found in palatine tonsils?
What other important histological features are there?
Nonkeratinized stratified squamous
- Tonsillar Crypts: 10-20 deep invaginations
- Dense CT
What type of epithelium is found in pharyngeal tonsils?
What other important histological features are there?
Pseudostratified columnar ciliated squamous epithelium
- Posterior wall of nasopharynx
- Invaginated mucosa but no crypts
- Thin capsule
What type of epithelium is found in lingual tonsils?
What other important histological features are there?
Stratified squamous epithelium
- Base of tongue
- Crypts
- No capsule
What two parts is the teeth divided into?
What is the bulk of the tooth made up of?
Divided into:
-
Crown: projects into oral cavity and protected by enamel
- What you see in mouth
-
Root: Embedded in alveolar ridge of alveolus (tooth socket)
- Invested by a thin layer of cementum
Mostly made of dentin
Dentin
What is its composition?
What does it enclose?
What is its function?
- Composed of calcified organic matrix
- similar to bone
- Contains central pulp cavity
- Has neurovasculature, lymphatics, and mesenchymal cells
Where are dentinal tubules found?
Radiating from pulp chamber to enamel rods
What structure attaches bone to the cementum of the tooth?
Periodontal Ligament
What substance holds the enamel rods together?
Interprismatic material
Where would Lines of Retzius be found?
In the enamel
What are these structures?
What structure is this?
What are the structures labelled?
Dental Tissue
