BIO E121 Lecture 14: Bio_E_121_-_Class_14_(Spring)
Document Summary
Group of similar type of cells that work together to serve a common function. Discuss the cellularity, polarity, attachment, and vascularity of epithelial tissue. Cells bounded closely together to form membranes/sheets fused by junctions. Has an exposed apical surface (free surface) Has an attached basal surface (close to basement membrane) Basel layer is attached to the underlying connective tissue. Depends on diffusion of nutrients from underlying connective tissue. Describe and illustrate the four shapes of epithelial tissue. Thin, flat cells / scale-like without nuclei. Cube, found in many cells, centered, round nucleus. Columnar cells longer than they are wide, nuclear near the base, small, finger-like folds. Microvilli function: increase surface area of cell location: secretion. Stereocilia function: longer microvilli location: found in the duct. Exocrine: secrete into duct leading to body surfaces, cavities, or organs. Endocrine: lack ducts and secretes products/hormones, into space outside of the cell. Erythema: oxygenated redness of skin patchy.
