Histology of Nasal & Oral Cavities Flashcards
What type of epithelium is respiratory epithelium made of?
Pseudostratified Columna Ciliated Epithelium
What are the “hallmarks” of respiratory epithelium?
- Cilia
- Goblet cells
- Thick basement membrane
Just beneath the respiratory epithelium, there is the ________ ________ which has a rich, vascular network with a complex set of capillary loops.
Lamina Propria
Respiratory epithelium also has non-ciliated ______ ______, which are stem cells.
Basal cells
The nasal cavities are divided by what?
Nasal Septum
There are 3 regions within the nasal cavity, which are…
Nasal Vestibule
Respiratory Region
Olfactory Region
This region of the nasal cavity is just inside the nostrils, lined by skin.
Nasal Vestibule
This region of the nasal cavity is the inferior 2/3. It is lined with respiratory mucosa (epithelium).
Respiratory Region
This region of the nasal cavity is located at the apex (upper 1/3), and is lined by specialized olfactory mucosa (epithelium).
Olfactory Region
What is the function of the nasal cavities?
Adjusts temperature and humidity of inspired air.
***Warms air, because if we took in cold air it could cause tissue damage over time.
What enhances the ability of the nasal cavities to adjust air temperature and humidity?
Turbinate bones (conchae) – provide larger surface area
These are air-filled spaces in the bones of the walls of the nasal cavity.
Paranasal Sinuses
Paranasal Sinuses are extensions of the _________ region of the nasal cavity, lined by _________ epithelium.
Respiratory
Respiratory
Sinuses communicate with nasal cavities via narrow openings into the respiratory mucosa. Mucous produced in the sinuses is swept into the nasal cavities by ________ movements.
Ciliary
***Remember, respiratory epithelium is ciliated
________ are often subject to acute infection after viral infections of the upper respiratory tract. Severe infection may require physical drainage.
Sinuses
What type of epithelium is within the Nasal Vestibule?
Keratinized Stratified Squamous Epithelium (skin)
***This is external opening, nares/nostrils
Olfactory mucosa (epithelium) is very similar to respiratory epithelium, except for what “hallmarks”?
- Dramatically thicker
- Lacks Goblet cells
- Thin basement membrane
Olfactory mucosa (epithelium) is made of what type of epithelial tissue?
Pseudostratified Ciliated Columnar Epithelium
***Same as Respiratory Epithelium
Olfactory mucosa (epithelium) contains receptors for what?
Sense of smell
In place of Goblet cells, Olfactory mucosa has these.
Olfactory Glands – serous secretions that dissolve odorant molecules
Why is the Olfactory mucosa in the superior 1/3 of the nasal cavity?
Because it has receptors for smell, and it needs to be close to the Olfactory bulb and brain so it can relay information.
These cells have a single dendritic process and have specialized, nonmotile cilia with odorant receptors.
Olfactory receptor cells
***Also called Olfactory receptor nerves (ORNs)
In Olfactory receptor cells, ligand binding to odorant receptors causes signals to be sent to the…
Olfactory Bulb
Why type of receptor are the odorant receptors?
GPCRs
***Has secondary messenger
Olfactory Glands secrete mucous across the epithelium, which allows ________ molecules to get trapped. Based on the molecule trapped, specific ORNs will be stimulated.
Odorant
These are stem cells for Olfactory Receptors and supporting cells.
Basal cells
These are ciliated, columnar epithelial cells that are in contact with CN V.
Brush cells
These cells provide mechanical and metabolic support to the Olfactory Receptor cells.
Supporting/Sustentacular cells
The oral cavity is lined by a protective mucous membrane, called the ________ ________.
Oral mucosa
What type of epithelium is within the oral cavity?
Stratified Squamous with varying keratinization (depending on location in mouth)
The oral mucosa is supported by dense collagenous tissue, called the…
Lamina Propria
The Lamina Propria in the oral cavity is connective tissue composed of…
Fibroblasts
WBCs
Collagen fibers
What are the two layers of the Lamina Propria?
Papillary Layer
Dense Layer
This layer of the Lamina Propria is superficial, loose CT with neurovasculature.
Papillary Layer
This layer of the Lamina Propria is deep, dense irregular CT with large amounts of fibers. This is the more supportive layer.
Dense Layer
In the oral cavity, a _________ layer is present depending on the location. It is comprised of loose CT, adipose tissue, and salivary glands.
Submucosal
This provides a protective surface for the hard palate, gingiva, and dorsal surface of the tongue (i.e., when biting apple with front teeth).
Masticatory Mucosa
What type of epithelium is Masticatory Mucosa made of?
Keratinized OR Parakeratinized Stratified Squamous Epithelium
What is the difference between Keratinized and Parakeratinized epithelium (as in Masticatory Mucosa)?
Parakeratinized still have their nuclei, while keratinized do not.
In Masticatory Mucosa, superficial cells do not lose their nuclei and cytoplasm does not stain intensely with eosin. The nuclei are _________ (highly condensed) and remain until the cell is exfoliated.
Pyknotic
The Masticatory Mucosa is highly interdigitated with _______ _______ and _________.
Rete Ridges
Papillae
***Very similar to Dermal Papillae and Ridges in epidermal skin and dermis!
T/F. Masticatory Mucosa has a very thick, prominent submucosa.
False. Masticatory Mucosa has a thin or absent submucosa.
This type of mucosa (epithelium) is found on the lips, cheeks, alveolar mucosal surface, floor of the mouth, inferior surfaces of the tongue, and soft palate.
Lining Mucosa
This type of mucosa has fewer Rete Ridges and CT Papillae, and has a distinct submucosa.
Lining Mucosa
What type of epithelium is Lining Mucosa?
Nonkeratinized Stratified Squamous Epithelium – may be parakeratinized in select locations
This mucosa is thicker than keratinized epithelium (Masticatory Mucosa) and consists of three layers.
Lining Mucosa
What are the three layers that make up the Lining Mucosa?
1) Stratum Basale
2) Stratum Spinosum
3) Stratum Superficiale
This layer of the Lining Mucosa is a single layer of cells resting on the basal lamina. Deepest layer.
Stratum Basale
This layer of Lining Mucosa is several cells thick, and is the middle layer.
Stratum Spinosum
This layer of Lining Mucosa is the most superficial layer of cells (aka the surface layer of the mucosa).
Stratum Superficiale
Specialized mucosa is associated with the sensation of ________ and is restricted to the ________ surface of the tongue.
Taste
Dorsal
The tongue has Masticatory and Specialized Mucosa, which are what type of epithelium?
Keratinized Stratified Squamous
The tongue has Masticatory and Specialized Mucosa that covers the muscular surface. It contains ________ ________ and taste buds responsible for gustation.
Lingual Papillae
These are structures of keratinized epithelium with Lamina Propria. They small, elevated structures of specialized mucosa and some of which are associated with taste buds.
Lingual Papilla
This type of papillae are the most wide-spread. They move food toward the pharynx for swallowing a gives the dorsal surface of the tongue a velvety texture. Shaped like fine-pointed cones and has NO taste buds!
Filiform Papillae
This type of papillae are vertical ridges on the lateral surface of the tongue in more posterior regions. They provide taste sensation.
Foliate Papillae
This type of papillae is on the dorsal surface of the tongue, and is found in lesser numbers. Provides taste sensation.
Fungiform Papillae
This type of papillae consists of 7-15 mushroom-shaped structures, anterior to sulcus terminalis. They have a sunken appearance and are surrounded by a trench. Hundreds of taste buds are present. Most posteriorly located papillae.
Circumvallate Papillae
These are barrel-shaped organs that perceive food molecules. They are comprised of 30-80 spindle-shaped cells that extend form the basement membrane.
Taste Buds
What are the 5 taste sensations taste buds can detect?
Sweet Salty Sour/Acidic Bitter Umami
Each taste bud can discern all five tastes but appear to concentrate on ______ of the five.
Two
In what other locations are taste buds present besides the tongue?
Glossopalatine Arch
Soft Palate
Posterior surface of Epiglottis
Posterior wall of Pharynx
The sensory cells within taste buds give off microvilli called…
Taste hairs
These are elongated cells that extend from the basal lamina of the epithelium to the taste pore. They have microvilli that will extend through the pore.
Neuroepithelial (sensory) cells
Neuroepithelial (sensory) cells synapse with afferent sensory neurons of which cranial nerves?
CN VII
CN IX
CN X
These are elongated cells that extend from the basal lamina to the taste pore and contain microvilli on their apical surface. They do NOT synapse with the nerve cells.
Supporting cells
These are small cells located in the basal portion of the taste bud, near the basal lamina. Stem cells for neuroepithelial (sensory) cells and supporting cells.
Basal cells
These are large, irregular masses of aggregated lymphoid tissue. Nodules are typically dispersed singly in a random manner.
Tonsils
Where are tonsils located?
Mucosa of posterior oral cavity, oropharynx, and nasopharynx
_______ help protect against inhaled or ingested substances and can be partially encapsulated. Function in immunology.
Tonsils
This is the component of the tonsils where pathogens get stuck, and the lymphatic nodules then attack the pathogens because they are highly populated with lymphocytes.
Tonsillar Crypts
This tonsil type is lined with nonkeratinized stratified squamous epithelium and possesses 10-20 deep invaginations called Tonsillar Crypts. Epithelial lining is densely populated with lymphocytes and dense CT acts as a partial capsule.
Palatine Tonsil
This tonsil type is a single structure on the posterior wall of the nasopharynx. It is covered with Pseudostratified Columnar Ciliated Epithelium. It has a thin underlying capsule and invaginated mucosa with shallow inholdings. NO crypts.
Pharyngeal Tonsil
This tonsil type is positioned alongside the base of the tongue. It is covered with Stratified Squamous Epithelium and possesses germinal centers. Has varying number of crypts. Lacks a capsule.
Lingual Tonsil
The teeth are divided into what two major components?
Crown
Root
The tooth crown projects into the oral cavity and is protected by ________. The root is embedded in the alveolar ridges of an ________ (tooth socket).
Enamel
Alveolus
The bulk of the tooth (root and crown) is made up of ________, which encloses a central chamber that contains ________.
Dentin
Pulp
The root of the tooth is invested by a thin layer called…
Cementum
Dentin is composed of a calcified organic matrix similar to that of bone, as well as inorganic components in its matrix such as…
Calcium Hydroxyapatite Crystals
These are parallel tubes that radiate to the periphery of the dentin.
Dentinal tubules
This is a translucent substance composed of parallel enamel rods (prisms) of calcium hydroxyapatite. The rods are cemented together by an almost equally calcified interprismatic material. Hardest material in the body!
Enamel
***Superficial to dentin
Prominent lines that cross enamel diagonally represent incremental ________ lines.
Growth
This is a very thin, amorphous calcified tissue (calcium hydroxyapatite) into which the Periodontal L. is anchored. It covers the dentin in the root and is thicker towards the apex of the root.
Cementum
*** “Cements” tooth in sockets
This is the core of the tooth, deep to dentin. It consists of loose, mesenchymal CT which has collagen fibers, fibroblasts, and mesenchymal stem cells.
Pulp
T/F. Pulp is highly vascular, well-innervated, and provides nutrition to dentin. It can form a reactive dentin due to chronic injury.
True
***It’s what gives dark appearance of tooth when it “dies” due to damage
This consists of the Cementum, Periodontal L., Alveolar bone, and Gingiva.
Periodontium
This ligament inserts into the Cementum and Alveolar bone that lines the Alveolus. It is comprised of collagen fibers.
Periodontal Ligament (PDL)
When we lose teeth as a child, the PDL becomes detached via what cells?
Osteoclasts
