The Basale Surface is the opposite end of the apical surface The basale surface

The basale surface is the opposite end of the apical

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-The Basale Surfaceis the opposite end of the apical surface. The basale surface is always attached to the basement membrane. All epithelial tissues are bound to a basement membrane.LATERAL SURFACE MODIFICATIONS-Lateral surface modifications are different kinds of attachment proteins that hold cells together. This is how we achieve multicellularity. The common motif is a junctional complex.
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-The junctional complex contains three components: Tight Junctions, Adhering Junctions, Desmosomes. Most apically located are transmembrane proteins that are attaching together between two cells to form tight junctions. This junction is a water tight barrier to prevent unwanted things to bypass the semi-permeable membrane.-Transmembrane proteins link together in the interstitial environment. The length that linking transmembrane proteins form is dependant on calcium. To split up a multicellular clump, just take away calcium and the cells will fall apart.-Just beneath the tight junctions are adheringjunctions(beltjunctions) which work as major structural structures to hold the cells together. They prevent the cells from being torn or ripped apart.-Just beneath adhering junctions are desmosomeswhich are individual little structures found throughout the cell that attach two cells together.-Gap junctionsare hydrophilic pores in the plasma membrane that are connected to one another. There’s a channel between one membrane to another which allows the cells to exchange chemicals to one another. This is how the cells communicate with one another. Cells communicate with their cytosolic molecules through gap junctions.-Gap junctions are not part of the junctional complex, but can interconnect cells together laterally, however that is not their primary function. Gap Junctions are there to allow cells to communicate with one another through their cytosols. BASAL SURFACE MODIFICATIONS-Basal surface modifications include attachment proteins called hemi-desmisomes (half of a desmisome). The hemidesmosome connects the cell basalely to the protein matrix called the basement membrane (basal lamina).-Epithelial tissue are classified in three ways: 1.Shape of the individual cells that make up the tissue(what they look like). Simple Squamousis a thin layer of flat cells. They are involved in secretion of serous fluid and are found as linings. Every single cell is attached to a basement membrane. The biggest function of a simple squamous epithelium is involved in diffusion. Diffusion is distance limited. The thin layer of a simple squamous epithelium allows for diffusion to occur quickly. (Ex:exchange of oxygen in the alveoli of the lungs).Mesophilia refers to simple squamous epithelium that line a body cavity. Endothelium refers to simple squamous epithelium that are the internal lining of blood vessels.
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