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22 Cards in this Set
- Front
- Back
sublingual gland
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positioned beneath the tongue and mbedded deepliy in the conn. tissue of the oral cavity.
- secretes thick stringy mucous |
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submandibular
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- post. poriotn of mandible lingual to mand. incisors, opens under the tongue, close to the frenulum .. walnut sized, secreates watery fluid with some mucou, more viscous than parotid gland
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parotid gland - near max. second molar - parotid duct goes
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near max. second molar and goes through, the buccinator muscles and enter the mouth opposite the max. second molars.
- largest of salivary - secretes clear and watery fluid. |
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types of these glands
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- these glands are tubulo - acinar glands
- they have secretory acini but the first part of the duct system originating from teh acini also participates in the secretory process. - the salivary glands are divided by conn. tissue septa into lobes, which are further subdivided into lobules. |
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two groups of secretory acini
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- serous - produce a liquid product
- mucous acini - produce a viscous product. |
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mucous acini
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usually ocntian flattened nuclei whih appear to be pressed against eh basel surface of the cell.
- secretory vesicles fill much of the apical cytoplasm. The secretory product has eith erbeen dissolved during the staining porcess or remains unstained. - small amounts of cytoplasm which remain between the vesicles gives the apical part of the cell a distinct spongy appearance. - ser |
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serous acini
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- round or slightly ovoid nucleus which is placed basally in the cell
- in an h and e stain the apical cytoplams may appear pinkish/ red or in well preserved tissue, contian reddish granules - the granules represent the vesicles whcih contian the secretory products of the cells - the digestion enzym alpha amylase is also secreted by the acinar cell. |
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saliva
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- lubricatdes oral cavity
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ducts of the salivary gland
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- interlobar and interlobular - function mainly in the conduit of the saliva and are formed by a stratified cuboidal or stratified columnar epithelium.
- the epithelium is replaced by the stratified squamous epithelium as they approach the opening of the oral cavity. |
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ducts of the salivary gland
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the product of serous glands is extensivlely modified by the initial part of the duct system.
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clusters of ectodermal cells form
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bud stage - tooth buds
- cap stage - enamel organs - bell stage - 4 layers more developed version of enamle organ - enamel organ - produces only enamel and intermediate cementum |
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staging method 1
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oral mesenchymal cells
- during crown formatio, become active around the bud - some cells sit inside the cap - dental papilla - produce odontoblasts, pulp and dentin - mesenchym surrounding the cap = dental sac/ dental follicle - produces cementum, alveolar bone, contents of PDL space |
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staging method 2
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initiation method - bud shaped appearance of ectoderm is the first visible sign of tooth formation
- proliferation stage - cap shaped enamel organs results from rapid cellular activity (proliferation) of teh "bud" cells - while the enamal organ is in teh bell stage - morphodifferentiation - histodifferentitation - specific cells identified - ameloblasts - odontoblasts - apposition stage - mineralization stage - mineralie immature enamel and predentin |
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4 layers of enamel organ at the bell stage
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- outer enamel epithelium
- inner enamel epithelium become ameloblasts - stellate reticulum - stratum intermedium - cervical loop - root formation activity begins here as crown formation is completed. - outer and inner epithelial cells meet - establishes the dentinoenamel junction. |
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cervical loop is the start of what
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root formation!
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establishment of DEJ
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- cell signaling
- results in the alignment of precursor cells for formation of enamel and dentin ameloblast appears BEFORE odontoblast - odontoblast produces dentin first though, then ameloblasts produces enamel. |
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teh cervical loop
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relatively inactive until the crown formation complete
- change from 4 layer structure to 2 layers - only the outer and inner enamel epithelial layers remain. - 2 layer structure known as hertwig's epithilial root sheath. - functions and activities of the root sheath. |
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root sheath funcitons and activities
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- inner enamel epithelial cells stimulate dental pappillae cells to become precursor odontoblasts --> odontoblasts --> tomes granular layer (predentin of this is produced by odontoblasts) --> this stimulaes more inner enamel epithelial cells.
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root sheath functions and activities - cementum formation process
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- the root sheath is a solid double layered wall of cells
- seperates teh dental sac from teh intermerdiate cementum - does not entirely dissapear - rather it develops large holes that allow cementogenic cells to get to teh surface of teh the intermediate cementum and deposit cementoid on that surface. |
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inner enamel epithelial cells
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stimulate dental papilla cells to become precursor odontoblasts
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precorsor odontoblasts
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cecome odontoblasts and secrete the predentin of tomes granular layer - this stimulates the inner enemel epithelium cells to secrete intermediate cementum.
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root sheath functions and activities
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- fibroblasts and myofibroblasts located in the dental sac also penetrate the sheath through the same gaps in teh root sheaths and embed themselves into the true cementum as extrinsic fibers.
- almost all the remaining parts of hertwigs root sheath disintegrate - a few remain in the apical area of the root. - seen in teh periodontal space - known as epithelial rests of malassez. |