Oral and Esophageal Histology Flashcards
Describe the general structural plan in the GI system?
- mucosa
- submucosa
- supporting wall
- adventitia/serosa
What are the three general surface areas/features for the lip?
- an outer cutaneous layer (skin)
- red area
3 oral mucosa
What’s the supporting wall for the lip?
orbicularis oris muscle
What is the supporting wall for the cheek?
the buccinator
The mucosa and submucosa of the cheek is similar to that of the lips except for what difference?
there’s more elastic tissue in the submucosa of the cheek to help reduce biting your cheeks
Where in the mouth is the stratified squamous epithelium keritinized and where is it not?
in general it’s keritinized in areas where there’s lots of stress from eating. So on the top of the tongue and on the hard palate it’s keritinized.
On the lips and lower part of the tongue it’s non-keritinized
Describe the submucosa of the hard palate and explain how it differs in different areas.
it’s absent in the midline
anterior 1/3 has lots of fat
posteiror 2/3 has lots of mucous glands
Describe the epithelium for the soft palate.
it’s stratified squamous keratinizing on the oral side and then pseudostratified columnar ciliated on the nasal side
Describe the submucosa of the soft palate.
it’s mostly mixed glands
What’s the supporting wall of the soft palate?
skeletal muscle and connective tissue
Why is the dorsal surface of the tongue’s mucosa complex?
its lamina propria is modified to form various papillae
The serous glands are beneath what papillae?
the circumvallate papillae
What do the mucous lgands empty into on the dorsal tongue?
tonsillar crypts
What nerves supply the anterior 2/3 of the tongue?
cranial nerves V and VII
What nerves supply the posterior 1/3 of the tongue?
cranial nerves IX and X
What are the 4 types of tongue papillae?
filiform
fungiform
circumvallate
foliate
What’s the most numerous papillae?
filiform
What’s the papillae that sticks up higher than the rest?
fungiform
Which are underdeveloped in humans?
foliate - located on the lateral sides of the tongue
On histology, why are filiform papillae really obvious/
they have lots of obvious keratinization
Where on the tongue are fungiform papillae most numerous?
towards the tip
What do the fungiform papillae look like?
slightly reddish club-shaped
What crnaial nerves innervates the fungiform papillae?
cranial nerve VII
What papillar are adjacent to the sulcus terminalis?
circumballate
What surrounds the circumvallate? What empties there?
a deep trench in which the serous glands of von Ebner empty
What cranial nerve supplies the circumvallate papillae?
CN IX
Taste buds are on what papillae?
circumvallate
fungiform
foliate
NOT on filiform
What layer are the taste buds embedded in?
epithelial layer
What are the three types of cells within taste buds?
sustentacular cells
taste receptor cells
basal cells (which give rise to the other 2)
WHat’s the outer layer of a tooth?
enamel?
What’s the middle layer that surrounds the pulp cavity?
dentin
What produces enamel?
ameloblasts
What produces dentin?
odontoblasts
What is the collagenous fibers with nerves that sort of act like a sling to keep the tooth in place?
the periodontal ligament
What connects the tooth to the periodontal ligament?
the cementum (formed by cementoblasts)
What type of bone does the periodontal ligament connect the tooth to?
alveolar bone - cancellous bone
What are the three major salivary glands?
parotid
submandibular
sublingual
What is the composition of saliva?
Water, cellular & bacterial debris, leukocytes, salts, salivary amylase, mucus, secretory IgA, desquamated epithelial cells
In general, what are the 4 ducts of a salivary gland?
excretory duct
striated duct
intercalated duct
alveolus
What are the specialized smooth muscle cells between serous/mucous cells and basement membrane in the secreotry unit?
myoeptihelial cells
What do myoepithelial cells do?
they contract to help discharge from the secretory cells
What epithelium is typically in the lumen of an excretory duct?
stratified columnar
How do excretory ducts differ from the striated?
excretory are bigger and striated are more eosinophilis
How do the striated duct differ from the intercalated?
intercalated area really tiny
Which are darker staining, mucous or serous alveoli?
serous are dark, mucous are light (plus mucous has nuclei at the outer edge)
What’s the cap that ou occasionally see on a mucous alveolus?
a serous demilune
What surrounds a parotid gland?
a very prominent connective tissue capsule CT separating lobes and lobules
True or false: striated and itnercalated ducts are prominent in the parotid gland.
true
Are acini primarily serous or mucous in the parotid gland
almost 100% serous
What additional tissue is found surrounding the acini and ducts of the parotid gland?
fat
Is the CT capsule more or less present in the submandibular gland compared to the parotid?
less conspicuous than the parotid
What ducts are well defined and which are scarce in the submandivulra/
striated are well defined while intercalated are scarce
What are the acini mostly in the submandibular
most are serous, but 10-25% are mucous
How does the CT capsule of the sublingual compare?
very indistinct
What ducts are prominent and what are not in the sublingual
excretory ducts prominent while striated are not prevalent and intercalated are non-existent
What are most of the acini in the subligual gland?
75% are mucous with serous demilunes and 25% are serous
What are the layers of the esophagus?
mucosa
submucosa
musclaris externa
adventitia
What glands are located in the upper 1/3 and lower 1/3 of the esophageal mucosa?
mucous glands called cardiac glands
Where are the mucous glands in the middle 1/3 of the esophagus?
in the submucosa
What else is located in the submucosal layer for the esophagus?
the submucosal nerve plexi
larger blood vessels and lymphatics
What type of muscle is in the muscularis externa?
skeletal muscle for the first 1/3, both in the middle and then smooth in the lower 1/3
What else is located in the muscularis externa?
myenteric nerve plexi
Does the esophagus have a serosa or an adventitia?
adventitia