This document discusses the four major types of adult tissues - epithelial, connective, muscle and nervous tissue. It provides details on the classification, structure and functions of each type of tissue. The key points are: 1) Tissues are classified based on structure, composition and function. The four major types are epithelial, connective, muscle and nervous tissue. 2) Epithelial tissues cover surfaces, line organs and form glands. They protect, absorb, secrete and transport. Connective tissues connect, support and protect other tissues. Muscle tissues contract to cause movement and pumping blood. Nervous tissues transmit electrical signals. 3) Each tissue contains different cell types and extracellular matrix to suit their functions.