Light microscope: The deepest layer of the epithelium, a layer of cubic or dwarf columnar cells; the nucleus is round, dark stained, and relatively few cytoplasm. Electron microscope: Hemidesmosomes are formed at the connection with connective tissue and are attached to the substrate.

Light Mirror (1) Polygonal cells located on the upper layer of the basal layer and have the most layers in the epithelium. (2) The nucleus is round, located in the center, with 1-2 nuclei (3) Intercellular bridge, gingival and hard palate epithelium are obvious

Electron microscopy: intercellular bridge, that is, intercellular desmosome connection

Proteins that make up desmosomes: (1) Desmosomal calcium-dependent mucin (transmembrane protein) -------Desmosomal core protein, desmosomal protein (2) Proteins that adhere to foul-attached in the membrane (conjunctive protein)------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Destroyed---Pemphigus vulgaris.

Light microscope: 2~3 layers of cells form the cytoplasm and contain basophilic transparent keratin particles, which are darkly stained and the nucleus is concentrated. If the surface is positive and angular, this layer is obvious; if the surface is not complete, this layer may not be obvious.

Function: The main component of transparent keratin particles is filament agglomeration, which is a protein formed in the spinous cell layer, which is conducive to the storage of calcium in the cell.

Light microscope: Located at the top of the epithelium, the cells are flat and the size is large

Orthokeratology: The organelles and nucleus disappear, the cytoplasm is filled with keratin, and the intercellular bridge disappears; red-stained cords.

Incomplete nuclei containing concentrated undisappeared

Keratinated scaly epithelium

Nonkeratinized scaly epithelium

Located on the base layer Embryos migrate from neural crest cells at week 11

Light microscope: cytoplasm is transparent, nucleus is round or oval;

Special staining: The cytoplasm has dendritic protrusions that penetrate deep into the basal cells.

Clinical: Melanin deposition is common in gingivals, hard palate, cheeks and tongue, and is also a good site for melanin lesions.

Mainly located in the spinous layer, a small number are located in the basal layer, also in the shape of dendritic, from hematopoietic tissue

Light microscope: cytoplasmic transparency, nuclear deep staining

Function: related to mucosal immunity, local lymph nodes can be accessed through the lamina propria lymphatic vessels

From the neural crest, located in the basal layer, is more common in the chewing mucosal epithelium A stress or tactile sensory cell

Light Mirror: Light dyeing

Electron microscope: generally no dendritic protrusions;

The electron-density membrane is covered with vesicles and contains neurotransmitters. This vesicle is common in the cytoplasm adjacent to the synaptic-like connection formed with nerve endings, which releases neurotransmitters and triggers impulses.

Halfbridge

Basement membrane: membrane structure between the epithelium and the layer propria. Three parts----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Deep part of fiber

Features: Electron-tight attachment fog can be seen on the inner side of the cell membrane of basal cells, and thin keratin filaments are inserted into the attachment fog.

composition: Focal-attached protein----BP230 and reticulin Transmembrane protein---------BP180 and integrin a6, *4

1. Transparent board lamina lucida It is about 45nm thick, close to the epithelial basal cells, and is a plate-like structure with low electron density. High electron density in regions corresponding to basal cell hemidesmosomes

2. Patch lamina densa It is about 50nm thick and is located on the deep side of the transparent plate, and is a granular or filamentous substance. High electron density. Substrate: transparent plate, sealed plate; from epithelial basal cells.

3. Screen board lamina reticularis Close to the propria, the electron density is lower than that of the dense plate Thicker transparent and dense plates, made of anchor fibers