LITR 101 Lecture Notes - Lecture 16: Basal Lamina, Spinal Cord, Microvillus
Document Summary
Groups of cells similar in structure that perform common or related function. Four basic tissue types: epithelial, connective, muscle, and nervous tissue. Upper free side, is exposed to surface or cavity: most apical surfaces are smooth, but some have specialized fingerlike projections called microvilli. Basal surface, lower attached side, faces inwards toward body: attaches to basal lamina, an adhesive sheet that holds basal surface of epithelial cells to underlying cells. Both surfaces differ in structure and function. Collagen- skin: important test question, avascular, but innervated. No blood vessels are found in epithelial tissue: must be nourished by diffusion from underlying connective tissues. First name indicates number of cell layers: simple epithelia are a single layer thick, stratified epithelia are two or more layers thick and involved in protection (example: skin) Second name indicates shape of cells: squamous: flattened and scale-like, cuboidal: box-like, cube, columnar: tall, column-like.
