Flashcards in Oral Cavity Histology Week 1 Deck (48):
Heinrich Waldeyer first described embryological, anatomical and functional studies about _________ and also named the chromosome
naso-oropharyngeal lymphatic tissue
True/False: The lumen of the GI tract is physically and functionally external to the body
True/False: The alimentary canal mucosa is the surface across which most substances enter the body
Describe the two parts of the oral cavity
1) Oral cavity proper - opening between teeth
incl tongue, major and minor salivary glands, tonsils
2) vestibule = the area in between the teeth and cheeks
Describe the three types of mucosa associated with the oral cavity and where they are located
1) Masticatory mucosa
2) Lining mucosa
3) Specialized (gustatory) mucosa
The masticatory mucosa is found in the gingiva and hard palate.
The lining mucosa is found everywhere else except the tongue.
The specialized mucosa is on the tongue.
What type of epithelia are found on the mucosa associated with the oral cavity? Any special structural features?
The masticatory and lining mucosae containing stratified squamous epithelium.
Both have parakeratinized type, masticatory mucosa also has keratinized type. Lining mucosa does not have keratinized type.
The specialized mucosa (gustatory) contain papillae and taste buds on its dorsal surface.
What two types of epithelium are found on the lip and where?
Stratified squamous on skin of lip
Parakeratinized stratified squamous on outside of lip (vermillion) [hair follicles are on vermillion]
Where on the lip are labial glands found?
What makes up the core of the lip?
skeletal muscle - called orticularis oris
What are the two types of teeth? How many of each are present?
deciduous (baby) - 20
permanent - 32
What are the three components of the tooth and where are they found?
Enamel, dentin, cementum
enamel is outermost, and dentin is just deep to enamel
The three components of the tooth are produced by different cells with different embryological origins. Describe.
Enamel is produced by ameloblasts, derived from the ectoderm.
Dentin is produced by odontoblasts, derived from neural crest cells.
Cementum produced by cementoblasts
What are the three sections of the tooth? Describe their components.
All three components contain dentin.
The crown and neck contain enamel.
The neck and root contain gingival epithelium.
The crown contains dentinal tubules, whereas the root contains the pulp chamber [nerves and vessels] and cementum.
What happens when gingival epithelium recedes?
dentin is exposed, acts like a sieve, liquids can flow right in and hit nerves
The tongue is divided into dorsal and ventral surfaces. Describe what is commonly found on the dorsal surface. [basics]
On the anterior 2/3 of the dorsal tongue, there are four types of lingual papillae
On the posterior 1/3, it contains a lingual tonsil which is part of Waldeyer's ring
On the anterior 2/3 of the dorsal surface of the tongue, there are four types of lingual papillae. Describe each.
1) Circumvallate papillae
2) Foliate papillae
3) Fungiform papillae
4) Filiform papillae
The circumvate are in front of the V-shaped sulcus terminalis.
The fungiform are on the marigin of the tongue and the filiform are on the surface.
Foliate are not abundant and seen primarily in newborns.
All contain taste buds except the filiform papillae.
The filliform papillae increase friction between the tongue and food (think cats).
The circumvate papillae are associated with Ebner's glands.
Describe the features on the ventral surface of the tongue
The ventral surface contains the lingual frenulum.
The deep lingual veins can be seen on both sides of the frenulum, allows sublingual admin of drugs
In addition to the three papillae of the dorsal tongue, taste buds are also found in which three regions?
posterior surface of epiglottis
What are the three types of cells that make up taste buds?
neuroepithelial sensory cells
What are the two types of palate? Where are they located and what type of epithelium do they contain? What is their main component?
1) Hard palate
2) Soft palate
Hard palate is the anterior 2/3 and soft palate is the posterior 1/3.
Bone is the main component of the hard palate, and skeletal muscle is the main of the soft palate.
The hard palate contains keratinized stratified squamous epithelium, whereas the soft palate contains respiratory and oral epithelium.
What happens to the soft palate when a person swallows?
It contracts, closing off the nasopharynx.
What are the two types of salivary glands? Describe overall features.
Major salivary glands are paired and contain long ducts that empty into the oral cavity. They contain serous and/or mucous cells in acini or tubules.
Minor salivary glands are located in the submucosa of different parts of the oral cavity.
Major salivary glands secrete saliva into three types of ducts. What are they?
intercalated ducts, striated ducts, interlobar ducts
What are the three major types of salivary glands?
Describe the types of secretion and how much saliva they produce.
2) Submandibular (submaxillary)
Parotid glands are the largest.
Parotid glands are strictly serous.
The other two are mixed; submandibular is primarily serous whereas sublingual is primarily mucous
Submandibular produce the most saliva at 60%, followed by parotid at 30% and sublingual at 10%
Submandibular and sublingual salivary glands make up a structure that is now known to be artifact but will probably still be on our board exams. What structure is this?
What are the three main cell types associated with salivary glands?
1) serous and mucous cells
2) myoepithelial cells (myosin/actin)
3) plasma cells/IgA
Describe the functions of saliva. How much is produced per day?
moistens food, lubricates GI tract, begins enzymatic digestion of carbs
1-1.5 L produced per day
Salivary glands release ______ and _____ into saliva
What modulates salivary composition and osmolarity?
What modulates salivary volume?
autonomic nervous system
The three types of lymphatic tissue in the GI tract are collectively called the Gut Associated Lymphatic Tissue (GALT) and found extensively throughout the tract. What are they?
1) Diffuse lymphatic tissue
2) Lymphatic nodules
Where are lymphatic nodules found in the GI tract? (2 layers)
submucosa and lamina propria
What are the four types of tonsils that make up Waldeyer's ring?
palantine, tubal, pharyngeal (adenoids), lingual
Describe the four histological layers of the GI tract
The mucosa contains epithelium, lamina propria, and muscularis mucosae.
Peyer's patches are found in the mucosa of the _____
The submucosa only contains gland in what two parts of the GI tract?
Describe the structure of the muscularis layer in the colon
True/False: Throughout the GI tract, the adventitia is the outermost layer.
FALSE - in some regions, serosa is outermost
Describe the histological structure of the esophagus
Mucosa, Submucosa, Muscularis externa
What type of epithelium is found in the mucosa of the esophagus?
stratified squamous epithelium
What is unique about the muscularis mucosae in the esophagus?
single longitudinal layer, robust smooth muscle
There are lots of esophageal glands. In what layer are they found? What types of glands are they and how do they drain?
Arranged in small lobules
Drained by a single duct
There are three regions of muscularis externa of the esophagus classified by the type of muscle found in each. Describe.
Upper 1/3 contains skeletal muscle
Middle 1/3 is mixed, but primarily smooth muscle
Lower 1/3 is smooth
What is the outermost layer of the muscularis externa of the esophagus?
Adventitia above diaphragm
Serosa below the diaphragm
Describe the structure of the muscularis externa of the esophagus
inner circular, outer longitudinal
The __________ is a ring of smooth muscle fibers connecting the esophagus to the stomach.
The upper sphincter (UES) is identified anatomically as the __________