Unformatted text preview: filtration. Cuboidal or columnar cells, which contain more organelles, secrete or absorb. • A smooth, free surface reduces friction. Microvilli increase surface area, and cilia move materials over the cell surface. • Desmosomes mechanically bind cells together, tight junctions form a permeability barrier, and gap junctions allow intercellular communication. • Hemidesmosomes mechanically bind cells to the basement membrane. Glands • A gland is a single cell or a multicellular structure that secretes. • Exocrine glands have ducts, and endocrine glands do not. Connective Tissue • Connective tissue holds cells and tissues together. • Connective tissue has an extracellular matrix consisting of protein fibers, ground substance, and fluid. • Collagen fibers are flexible but resist stretching, reticular fibers form a fiber network, and elastic fibers recoil. • Blast cells form the matrix, cyte cells maintain it, and clast cells break it down....
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- Fall '10
- Anthropology, Epithelial tissue, Epithelia, Stratified epithelium, Simple Epithelium, mechanically bind cells