Oral Bio Exam 2

Front 1

sublingual gland

Back 1

positioned beneath the tongue and mbedded deepliy in the conn. tissue of the oral cavity.

- secretes thick stringy mucous

Front 2

submandibular

Back 2

- 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

Front 3

parotid gland - near max. second molar - parotid duct goes

Back 3

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.

Front 4

types of these glands

Back 4

- 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.

Front 5

two groups of secretory acini

Back 5

- serous - produce a liquid product

- mucous acini - produce a viscous product.

Front 6

mucous acini

Back 6

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

Front 7

serous acini

Back 7

- 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.

Front 8

saliva

Back 8

- lubricatdes oral cavity

Front 9

ducts of the salivary gland

Back 9

- 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.

Front 10

ducts of the salivary gland

Back 10

the product of serous glands is extensivlely modified by the initial part of the duct system.

Front 11

clusters of ectodermal cells form

Back 11

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

Front 12

staging method 1

Back 12

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

Front 13

staging method 2

Back 13

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

Front 14

4 layers of enamel organ at the bell stage

Back 14

- 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.

Front 15

cervical loop is the start of what

Back 15

root formation!

Front 16

establishment of DEJ

Back 16

- 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.

Front 17

teh cervical loop

Back 17

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.

Front 18

root sheath funcitons and activities

Back 18

- 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.

Front 19

root sheath functions and activities - cementum formation process

Back 19

- 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.

Front 20

inner enamel epithelial cells

Back 20

stimulate dental papilla cells to become precursor odontoblasts

Front 21

precorsor odontoblasts

Back 21

cecome odontoblasts and secrete the predentin of tomes granular layer - this stimulates the inner enemel epithelium cells to secrete intermediate cementum.

Front 22

root sheath functions and activities

Back 22

- 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.