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UKCD Histo Oral Muco
Test objective answers for oral mucosa
Question | Answer |
---|---|
List 3 types of mucosa that are found within the oral cavity | Lining, masticatory and specialized. |
State a specific location of where each type would be found | Lining - under the tongue, floor of mouth, lining the cheek; Masticatory - hard palate, gingiva; Specialized - dorsum of the tongue. |
How is lining mucosa characterized? | Stratified squamous non-keratinizing epithelium, low CT papilla at the dermal-epithelium junction; cells retain nuclei through the uppermost layer and the cytoplasm is occupied with a large fluid-filled vacuole. |
How is masticatory mucosa characterized? | This staritified squamous epithelium is keratinized and has high CT papillae at the dermal-epithelium junction |
How does masticatory mucosa differ from lining mucosa? | The surface layers of masticatory mucosa are keratinized. The CT papillae of masticatory mucosa are generally higher. Masticatory mucosa generally exhibits a mucoperiosteum. |
What is the specific feature of the specialized mucosa that sets it apart from the other types? | Presence of specialized papillae. |
How does parakerantinized epithelium differ from orthokeratinized and/or non-kerantinized types? | Parakeratinized epidoes keratinize but no cellular destruction not forming squames as in ortho These cells retain their pyknotic (dead) nuclei through to the uppermost layers. In addition the stratum granulosum is absent or remains indistinct. |
Where is parakeratinized epithelium found? | On the regions of the attached gingiva. |
How is the structure of parakeratinized epithelium related to its function? | It has a smooth surface and is firmly attached to the underlying bone by a mucoperiosteum. This allows material to slide over the surface of the gingiva yet resist masticatory pressures. |
What three cell types are collectively referred to as intraepithelial nonkeratinocytes? | Merkel cells, Langerhan’s cells and melanocytes. |
Where in the epithelial layer are these 3 cell types located? | In or just above the stratum germinativum (basale). |
What is the function of each of these 3 cell types? | Merkel cells are unencapsulated mechanoreceptors; Langerhan’s cells are antigen presenting cells; melanocytes are cells that produce melatonin to shield the replicating DNA of underlying proliferative cells. |
List the 4 types of lingual papillae | Filiform, fungiform, foliate and (cirum)vallate. |
Where is each type primarily located on the tongue? | Filiform cover the dorsum of the tongue; fungiform are located on the tip and scattered over the dorsum, foliate are found along the lateral aspects while circumvallate are found in a V-shaped line just anterior to the sulcus terminalis of the tongue |
What are the distinguishing features of each type of lingual papilla? | Filiform- a sharp tip and minimal CT core; foliate are broad with an elaborately branched CT core; fungiform are mushroom-shaped with a vascular CT core; circumvallate are countersunk into the tounge, surrounded by a moat-like groove and have a core of CT |
Which papillae exhibit keratinization? | Filiform with fungiform becoming slightly keratinized in older age. |
Which papilla exhibit taste buds? | Predominately the circumvallate papillae although they may occasionally be found on the lateral aspects of foliate and fungiform. They are never found on filiform papillae. |
What three cell types compose a taste bud? | Basal cells, taste receptor cells and sustentactacular (supporting) cells. |
Which cell of the taste bud is responsible for receiving the taste stimuli? | Taste receptor cell |
Which cell, if any, is a bipolar neuron? | None. The taste receptor cells is a special sense receptor cell which is uncharacteristically NOT a bipolar neuron. |
How are taste stimuli washed from the taste pore? | The glands of von Ebner, located in the lamina propria as well as between the muscle bundles of the tongue secrete voluminous amounts of serous fluid that passes over the taste pores, flushing old taste stimuli from the hairs of the taste receptor cells. |