There are four main types of human tissue: epithelia, connective, muscular, and nervous tissue. Epithelia tissue covers surfaces and forms glands. It includes several layers and cell shapes. Connective tissue is made of cells and extracellular matrix. Its types include connective, cartilage, bone, and blood. Muscular tissue is made of muscle cells and has skeletal, cardiac, and smooth types. Nervous tissue contains neurons and supports cells in the brain, spinal cord, and nerves.