Extracellular material and mixtures of cells and extracellular material that are produced, excreted or accreted by an Organism. Included here are Substances such as saliva, dental enamel, sweat, hormones, and gastric acid.
||connective tissue||Connective tissue is one of the four basic types of animal tissue, along with EpithelialTissue, MuscleTissue, and NervousTissue. It develops from the mesoderm. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central nervous system, the three outer membranes (the meninges) that envelop the brain and spinal cord are composed of connective tissue. All connective tissue consists of three main components: fibers (elastic and collagen fibers), ground substance and cells. Not all authorities include Blood or lymph as connective tissue because they lack the fiber component. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes.[from Wikipedia]|
| ||epithelial tissue||Epithelium is one of the four basic types of animal Tissue, along with ConnectiveTissue, MuscleTissue and NervousTissue. It is a thin, continuous, protective layer of cells. Epithelial tissues line the outer surfaces of organs and BloodVessels throughout the body, as well as the inner surfaces of cavities in many internal Organs. An example is the epidermis, the outermost layer of the Skin. [from Wikipedia]|
| ||MuscleTissue||Nonrigid Tissue appearing only in Animals and composed largely of contractile cells.|
| ||nervous tissue||The type of Tissue that makes up NerveCells.|
| ||tendon||Tissue that connects Muscle to Bone.|
| ||wood||Tissue that comprises the inner trunk of BotanicalTrees. It is often used in constructing Buildings and other Artifacts. Wood is the principal substance making up a tree, and is distinguished from the bark, roots, flowers, seeds, fruit and leaves.|