In this second lab the main emphasis is on connective tissue and epithelium. The connective tissues are characterized by cells that produce and maintain a wide variety of extracellular material around themselves.
Extracellular material can be fluid, fibers, ground substance molecules, and minerals.
It is the extracellular matrix that determines the physiological and physicochemical properties of the connective tissue, e.g., the difference between bone, cornea, and blood. The connective tissue literally holds our bodies together. The main cell types in connective tissue proper include fibroblasts, macrophages, mast cells, plasma cells, fat cells and blood leukocytes. Epithelia line all of the cavities and free surfaces of the body. The cells are tightly bound together to form barriers to water, solutes and cells, thus separating one body compartment from another.