There are four main types of tissues in the body: epithelial, connective, nervous, and muscle tissue. Epithelial tissue covers surfaces and performs functions like protection, absorption, secretion, and sensation. Connective tissue is found throughout the body and performs supporting, binding, and protective functions. Nervous tissue is composed of neurons and neuroglia that conduct electrical signals. Muscle tissue contains three main types - skeletal, cardiac, and smooth muscle - that function to produce movement.