BICD 110 Lecture Notes - Lecture 21: Tight Junction, Gap Junction, Intermediate Filament
Document Summary
5 basic tissue types: blood cells, muscles, neuronal, epithelial, flat layer of cells, connective, few cells in the extracellular matrix, rest are fibers/packing material. Cell cell junctions exist between cells but most obvious between an epithelial sheet of cells. Bad if all cells in tight contact, nutrients o2 immune system cells cant get in. Instead most cell sheets separated by ecm (exn provides a solution to get nutritnets and. Only cells found in ecm are fibroblasts (secrete ecm components) and lymphocytes (macrophages, dendritic cells) Provides strength tendon: strong , weak up and down; strength in one direction cornea: thick, non deformable, clear light can go through: normal cornea: layers of collagen laid down at right angles, cataracts random assembly. Bone: laid down at right angles, then ca2++ precipitate added strong in all directions and hard stretch and relax with cross links (5x as stretchy as a rubber band) 1) skin shape retention [sun breaks]
