what are the 4 main types of body tissues?

Question

list and describe

Answer 1

* Epithelium - Tissues composed of layers of cells that cover organ surfaces such as surface of the skin and inner lining of digestive tract: the tissues that serve for protection, secretion, and absorption.
* Connective tissue - As the name suggests, connective tissue holds everything together. Some people consider blood a connective tissue. It should be noted that blood is not 'considered' connective tissue, it is connective tissue. (i.e. cells of connective tissue (blood) separated by an inorganic material (plasma). Plasma is the extracellular matrix that includes everything but the red/white blood cells. These tissues contain extensive extracellular matrix.
* Muscle tissue - Muscle cells contain contractile filaments that move past each other and change the size of the cell. Muscle tissue also is separated into three distinct categories: visceral or smooth muscle, which is found in the inner linings of organs; skeletal muscle, which is found attached to bone in order for mobility to take place; and cardiac muscle which is found in the heart.
* Nervous tissue - Cells forming the brain, spinal cord and peripheral nervous system.

Answer 2

http://en.wikipedia.org/wiki/Body_tissue