Tissue(s): the material of which an animal or plant body, or any of its parts or "organs," is composed. (Oxford)

In the case of “multicellular”  “organisms” such as plants and animals, many cells of the same type associate with each other to form tissues. An example is “muscle” tissue. (Brooker, 4) The body has 4 main tissue types - connective tissue, epithelium, muscle, and nervous. Tissues intertwine and layer to form the organs of the body, which in turn connect into organ systems. (Lewis, 5-6)


Connective Tissue: clusters of cells that connect, anchor, and support the structures on an animal’s body. (Brooker, G-8) The tissue that supports, binds, or separates more specialized tissues and organs or functions as a packing tissue of the body. (OxfordMed)

Fascia: connective tissue forming layers of variable thickness in all regions of the body. (OxfordMed)

Deep Fascia: envelops organs and tissues. Includes sheet and soft fibrous tissue that enclose muscles and muscle groups and separate them into layers. (OxfordMed)

Superficial Fascia: found immediately beneath the skin. (OxfordMed)

Trabecula: any of the bands of tissue that pass from the outer part of an organ to its interior, dividing it into separate chambers. (OxfordMed) Plural - ‘trabeculae.’ Adjective - ‘trabecular.’

Epithelium: composed of cells that are joined together via “tight junctions” and form continuous sheets. Covers or forms the lining of all internal and external body surfaces, including skin. (Brooker, 203) Covers the external surface of the body and lines hollow structures (except blood and lymphatic vessels.) It is derived from embryonic “ectoderm” and endoderm. (OxfordMed) Adjective - ‘epithelial.’

Capsule: a “membrane,” sheath, or other structure that encloses a tissue or organ. (OxfordMed)

Endothelium: the single layer of cells that lines the heart, blood vessels, and lymphatic vessels. Derived from embryonic “mesoderm.” (OxfordMed)

Muscle Tissue: any of the fibrous bands or bundles of tissue which act to produce movement in or maintain the position of parts of the human or animal body. (Oxford)

Nervous Tissue: clusters of cells that initiate and conduct electrical “signals” from one part of an animal’s body to another part. (Brooker, G-24)