Epithelia, tissue and growth disorders Certain cells of the body are specialised for specific functions. A tissue is defined as a group of cells with a similar structure and function, there are 4 main types of tissue: Epithelium Connective tissue Nervous tissue Muscle Epithelia Epithelia are derived from 3 layers, referred to as the germ layers; the ectoderm, mesoderm and endoderm. They line and cover all of the body's surfaces with the exception of articular cartilage, tooth enamel and the...
