Histology of the Nasal & Oral Cavities Flashcards
What type of cell layer makes up respiratory epithelium?
Pseudostratified columnar ciliated epithelium
What are the hallmarks of respiratory epithelium?
Lots of cilia, many goblet cells, thick basement membrane
What is the lamina propria?
Under the basement membrane, has a rich vascular network
Where can you find respiratory epithelium in the head?
Nasal cavities and paranasal sinuse?
What are the three divisions of the nasal cavity?
Nasal vestibule (nostrils), respiratory region (inferior 2/3), olfactory region (superior 1/3)
What type of cell layer makes up the nasal vestibule?
Keratinized stratified squamous epithelium (that part is still skin on the outside)
What type of cell layer makes up the respiratory region of the nasal cavity?
Pseudostratified columnar ciliated epithelium
What type of cell layer makes up olfactory mucosa?
Pseudostratified ciliated columnar epithelium
What are the hallmarks of olfactory mucosa?
Much thicker/longer columnar cells, LACKS goblet cells, thin basement membrane
Why are there no goblet cells in olfactory mucosa?
Olfactory glands produce serous secretions to dissolve odorant molecules
What cell types are found in olfactory mucosa?
Olfactory receptor cells/neurons (odorant receptors), basal cells (stem cells), brush cells (ciliated), supporting/sustentacular cells (mechanical/metabolic support)
What type of cell layer makes up oral mucosa?
Stratified squamous types (varying keratinization)
What are the three types of oral mucosa?
Lining, masticatory, and specialized
What are the layers of the lamina propria?
Papillary (superficial, loose CT w/ neurovasculature) and dense (deep, dense irregular CT)
What are rete ridges?
Layer that zig-zags and keeps oral mucosa attached to underlying CT
Where is masticatory mucosa found?
Hard palate, gingiva, dorsal surface of tongue (places that need extra protection)
What type of cell layer makes up masticatory mucosa?
Keratinized and/or parakeratinized stratified squamous epithelium
What does parakeratinized mean?
Superficial cells do NOT lose their nuclei
Is there a submucosal layer under masticatory mucosa?
VERY thin layer or absent
Where is lining mucosa found?
Lips, cheeks, alveolar mucosal surface, floor of mouth, inferior tongue, soft palate
What type of cell layer makes up lining mucosa?
Nonkeratinized OR parakeratinized stratified squamous epithelium
Does lining mucosa have rete ridges?
Yes but fewer than masticatory
What are the layers of lining mucosa?
Stratum basale, stratum spinosum, stratum superficiale
Where is specialized (oral) mucosa found?
Dorsal surface of tongue
What is specialized (oral) mucosa associated with?
Sensation of taste (contains taste buds)
What type of cell layer makes up the specialized (oral) mucosa?
Keratinized stratified squamous, contains lingual papilla which can house taste buds
What are lingual papilla?
Structures of keratinized epithelium that can house taste buds
What are the types of lingual papillae?
Filiform papillae, foliate papillae, fungiform papillae, circumvallate papillae
What are filiform papillae?
Most widespread, NOT associated with taste. Give the tongue its texture, shaped like “fine-pointed cone”
What are foliate papillae?
On lateral edges of tongue, create crevices that trap partially digested food mixed with saliva. Associated with taste buds. Are rectangle/square shaped and flat on top.
What are fungiform papillae?
Associated with taste buds, lower number than foliate papillae. Are rounded like the top of a mushroom.
What are circumvallate papillae?
Large, restricted to posterior surface of tongue. Have ~7-15 of them, sit in V-shape anterior to sulcus terminalis. Associated with many deep crevice and hundreds of taste buds
What is a taste bud comprised of?
30-80 spindle-shaped cells that extend from basement membrane
What do the microvilli of the sensory cells in taste buds go through to get to the crevice?
Through taste pores
What are the 5 taste sensations?
Sweet, salty, sour/acidic, bitter, umami
What do sensory cells synapse with after sensing taste?
Afferent sensory neurons of CN VII, IX, or X
What are tonsils?
Irregular masses of aggregated lymphoid tissue that function in immune response (can be encapsulated)
What types of tonsils do we have?
True palatine tonsils bilaterally, a single lingual tonsil (posterior tongue), and pharyngeal tonsils (adenoid) (posterior nasopharynx)
What are lymphoid nodules?
Highly populated areas of lymphocytes
What type of cell layer makes up the palatine tonsils?
Nonkeratinized stratified squamous epithelium
What are the deep invaginations in the tonsils called?
Tonsillar crypts
What type of cell layer makes up the pharyngeal tonsils?
Pseudostratified columnar ciliated epithelium (associated w/ nasal cavity)
What type of cell layer makes up the lingual tonsil?
(Keratinized) stratified squamous epithelium
Which tonsils have tonsillar crypts?
Palatine tonsils have many
Pharyngeal tonsils have none (just have shallow infoldings)
Lingual tonsils have few
What are the 5 major components of teeth?
Enamel, dentin, pulp, cementum, and PDL
What is dentin?
Composes the bulk of the tooth (root and crown). Made of calcified organic matrix similar to that of bone, contains calcium hydroxyapatite. Composed of dentinal tubules.
What is enamel?
Translucent layer of parallel enamel rods that keeps dentin safe. Also composed of calcium hydroxyapatite (way more than dentin).
What is cementum?
Amorphous calcified tissue (calcium hydroxyapatite) which anchors PDL, covers dentin in root/tooth socket below gums after enamel stops
What is pulp?
Core of tooth deep to dentin, gives nutrients to dentin.
What is PDL?
Periodontal ligament that inserts into cementum and alveolar bone, composed of dense CT
