Histology of the Oral and Nasal Cavity Flashcards
Respiratory mucosa = _____ epithelium
Pseudostratified columnar ciliated
The respiratory mucosa rests on a thick basement membrane as well as a lamina propria rich in blood vessels, serous glands, and mucous glands. The mucous is propelled by ____ toward the pharynx
Cilia
Cell types associated with respiratory mucosa
Ciliated columnar cells
Brush cells (short columnar cells with blunt microvilli)
Lymphocytes
Non-ciliated stem cells
What is the most abundant cell type associated with respiratory mucosa?
Ciliated columnar epithelial cells
What parts of the nose are lined by respiratory mucosa?
Nasal cavities
Paranasal sinuses
The ability of the nasal cavity and nasal mucosa to adjust temperature and humidity of inspired air is enhanced by the large surface area provided by the _______ bones
Turbinate
Vestibule of the nasal cavity is lined by ____ epithelium
Keratinized stratified squamous
Posterior to the vestibule, the nasal cavity is lined by _____ epithelium
Pseudostratified columnar ciliated
Olfactory mucosa = _____ epithelium
Pseudostratified
Types of cells associated with the pseudostratified olfactory epithelium (olfactory mucosa)
Basal stem cells
Columnar support cells
Bipolar olfactory neurons
What glands are associated with the olfactory mucosa and what is their function?
Bowman’s glands = specialized olfactory glands that produce serous secretion that dissolves odor molecules so that we can better sense them
The dendrites of olfactory neurons have ‘olfactory hairs’ which are nonmotile cilia that serve what purpose?
Nonmotile cilia have specialized membrane receptors for odorant molecules
Ligand binding causes signals to be sent to olfactory bulb
T/F: olfactory epithelium is dramatically thickened and contains goblet cells
False; it IS dramatically thickened, but olfactory epithelium LACKS goblet cells
3 layers of olfactory epithelium
Basal cells (deep) within basement membrane
Olfactory neurons in the middle
Supporting/sustentacular cells and mucous layer
T/F: the nasopharynx is lined with respiratory epithelium
True
The nasopharynx is lined with respiratory epithelium. Patches of ______ epithelium occur with increasing age. This occurs near the ______ end and most extensively in smokers
Squamous; inferior
The nasopharynx also contains a lamina propria with serous and mucous glands. The predominant feature is the presence of large masses of _____ tissue. This forms a component of ______ ______, which protects the entry portals of the respiratory and GI tracts
Lymphoid; Waldeyer’s ring
Lymphoid tissue of the nasopharynx is particularly prominent in children; it bulges into the lumen of the nasopharynx forming the __________
Pharyngeal tonsil (adenoid)
The epithelium of the oral mucosa is _________ type, but it has varying _______
Stratified squamous; keratinization
The oral mucosa is subdivided into what 3 categories?
Lining mucosa
Masticatory mucosa
Specialized mucosa
The oral mucosa is supported by a dense collagenous tissue, the lamina propria. This contains connective tissue with what components?
Fibroblasts
White blood cells
Collagen fibers
2 layers of lamina propria in oral mucosa
Papillary layer = superficial, loose CT with neurovasculature
Dense layer = deep, dense irregular CT with large amounts of fibers
A submucosal layer is present in the oral mucosa depending on location. This is comprised of what 3 components?
Loose CT
Adipose tissue
Salivary glands
When the oral mucosa is nonkeratinized, what are its 3 layers?
Basal layer: deepest layer of cuboidal cells that undergo mitosis
Intermediate layer: stacked, polyhedral shaped cells that no longer undergo mitosis
Superficial layer: stacked polyhedral shaped cells with outer cells flattened into squames
When the oral mucosa is keratinized, what are its 4 layers?
Basal layer: single layer of cells undergoing mitosis
Prickle cell layer: bulk of tissue, lose ability to undergo mitosis
Granular layer: flat, stacked cells with prominent keratohyaline granules
Keratin layer: flat cells that lack nuclei, full of keratin (has squames)
Keratinized stratified squamous epithelium associated with the oral mucosa contains keratohyaline granules in the granular layer. What are keratohyaline granules?
Precursor form of keratin
The lining mucosa (oral mucosa subtype) has soft surface texture, moist, and the ability to stretch/compress surface. This comprises the _____, _____, and ______ mucosa, as well as the mucosal lining of the floor of the mouth, and the ventral surface of the ______ and ______
Buccal; labial; alveolar
Tongue; soft palate
Is the lining mucosa (subtype of oral mucosa) keratinized or nonkeratinized? Is there an underlying submucosa?
Nonkeratinized; commonly has underlying submucosa
[the interface with the LP is generally smoother in appearance with fewer rete ridges and connective tissue papillae]
Is the masticatory mucosa (subtype of oral mucosa) keratinized or nonkeratinized? Is there an underlying submucosa?
Keratinized; submucosa is thin or absent
The masticatory mucosa (subtype of oral mucosa) has a rubbery surface with good resiliency. Where is it found?
Found on the hard palate, attached gingiva, and dorsal surface of tongue
The masticatory mucosa is highly interdigitated with _____ _____ and papillae
Rete ridges
Is the specialized mucosa (subtype of oral mucosa) keratinized or nonkeratinized?
The specialized mucosa is made up of discrete structures composed of KERATINIZED epithelium and lamina propria
Where is the specialized mucosa (subtype of oral mucosa) found?
Dorsal and lateral surfaces of the tongue in the form of lingual papillae
The tongue is a mass of striated skeletal muscle covered by oral mucosa. The surface is composed of ______ and ______ mucosa.
________ epithelium covers the muscular surface
Masticatory; specialized
Keratinized stratified squamous
Lingual papillae may contain ____ ______, which are barrel-shaped organs that perceive food molecules
Taste buds
Taste buds are comprised of 30-80 spindle-shaped cells that extend from the basement membrane. Taste cells contain taste receptors that make contact with food molecules via the ____ ______. Supporting cells support the taste bud, surrounding the taste cells on the outer part of the bud
Taste pore
4 types of taste buds
Foliate
Filiform
Fungiform
Circumvallate
Which of the following are the most common form of papillae, moving food toward the pharynx for swallowing?
A. Foliate
B. Filiform
C. Fungiform
D. Circumvallate
B. Filiform
These give dorsal surface of tongue a velvety texture and are shaped like a fine-pointed cone
Which of the following forms vertical ridges on the lateral surfaces of the tongue in more posterior regions and provides taste sensation?
A. Foliate
B. Filiform
C. Fungiform
D. Circumvallate
A. Foliate
Which of the following is found on the dorsal surface of the tongue in lesser numbers and provides taste sensation?
A. Foliate
B. Filiform
C. Fungiform
D. Circumvallate
C. Fungiform
Which of the following consists of 7-15 raised mushroom-shaped structures anterior to sulcus terminalis, have a sunken appearance surrounded by a trench, and has hundreds of taste buds present?
A. Foliate
B. Filiform
C. Fungiform
D. Circumvallate
D. Circumvallate
What are all the taste sensations that can be detected by the cells of the tongue? What region do they correspond to?
Sweet (sugars) = tip of tongue
Salty (sodium) = anterior and lateral to tip of tongue
Sour (acidic) = lateral margin of tongue
Bitter = posterior tongue
Umami (savory) = MSG
T/F: each taste bud can discern all five tastes
True; but they appear to concentrate on 2/5
Taste buds on the palate register primarily what 2 tastes?
Bitter
Sour
Taste buds of the _____ and ______ register all 5 taste modalities
Posterior pharynx; epiglottis
______ = aggregates of lymphoid nodules clustered around posterior opening of oral and nasal cavity, organized into waldeyer’s ring
Tonsils
The palatine tonsil is positioned bilaterally in the oropharynx. It is covered by _____ epithelium and surrounded by _____ _____
Stratified squamous; tonsillar crypts
The palatine tonsil epithlelial lining is densely populated with _______; its dense connective tissue acts as a partial capsule, and they contain _____ ______
Lymphocytes; germinal centers
The pharyngeal tonsil is a single structure along the posterior wall of the nasopharynx. It is covered with a _____ epithelium
it has a thin underlying capsule, invaginated mucosa with shallow infoldings, and no crypts.
Pseudostratified columnar ciliated
The lingual tonsil is positioned along the base of the tongue, covered with ______ epithelium similar to palatine tonsils. There are associated ____ ____ with varying numbers of crypts. However, the lingual tonsil lacks a distinct ______
Stratified squamous; germinal centers; capsule
Teeth are grossly divided into crown and root. The crown projects into the oral cavity and is protected by _____; the root is embedded in the alveolar ridge of an _______ (tooth socket)
Enamel; alveolus
The bulk of the tooth (root and crown) is made up of _______ which encloses a central cavity/chamber containing _____
Dentin; pulp
What is the pulp of the tooth made up of?
Supporting tissue containing neurovasculature, lymphatics, and mesenchymal cells
The root of the tooth is invested by a thin layer of ________
Cementum
Dentin is composed of a calcified organic matrix similar to that of bone. It contains inorganic components in its matrix called ____ ____ crystals.
Calcium hydroxyapatite
____ ___ = parallel tubes that radiate to the periphery of the dentin
Dentinal tubules
On histological slides: fine, long tubules can be observed in the _______
Prominent lines that cross ______ diagonally represent incremental growth lines
Dentin
Enamel
Enamel is made up of translucent substance composed of parallel enamel rods (prisms) of _____ ______.
The rods are cemented together by an almost equally calcified ____ material
Calcium hydroxyapatite
Interprismatic
______ is an amorphous calcified tissue (calcium hydroxyapatite) into which the periodontal ligament is anchored
Cementum
T/F: the cementum is thicker towards the apex of the root of the tooth
True
The pulp of teeth is highly vascular and well-innervated. Why is this important?
The pulp provides nutrition to the dentin
[can also form reactive dentin d/t chronic injury]
Production of dental tissue comes from what 3 cell types? Which of these is lost during tooth eruption?
Odontoblasts: secrete pre-dentin
Ameloblasts: secrete enamel matrix
Cementoblasts: secrete cementoid matrix
[ameloblasts are lost during tooth eruption]
Within approximately 1 day of secretion from odontoblasts, predentin mineralizes to dentin. Cells extend an odontoblast process, which is surrounded by new matrix and becomes entrapped in ____ ____
Dentinal tubules
Ameloblasts are tall cells in contact with dentin. The enamel matrix they secrete will mineralize into enamel. The enamel matrix itself is secreted from ______ process.
Tome’s
Cementoblasts secrete cementoid matrix which mineralizes to cementum. Cells then become trapped forming ________
Cementocytes
The periodontium consists of what 4 structures?
Cementum
Periodontal ligament
Alveolar bone
Gingiva
The periodontal ligament inserts into _____ and ______ that lines the alveolus; it is composed of _____ fibers
Cementum; alveolar bone; collagen
