There are four main types of tissues in the body: epithelial, connective, muscle, and nerve tissue. Epithelial tissue covers surfaces and forms glands. It includes several subtypes like squamous, cuboidal, columnar, and pseudostratified epithelial cells. Connective tissue is found throughout the body and includes specialized cells and extracellular matrix. The main types are connective, adipose, bone, cartilage, and blood. Muscle tissue includes skeletal, smooth and cardiac muscle. Nerve tissue forms the brain, spinal cord and peripheral nerves.