There are four primary tissue types in the body: epithelial, connective, muscular, and nervous tissue. Epithelial tissue forms sheets that cover surfaces and line cavities. There are two types - simple epithelial tissue which is one cell thick, and stratified epithelial tissue with multiple cell layers. Connective tissue is found throughout the body and has three main components - connective tissue proper, dense connective tissue, and specialized connective tissues like blood, bone, and cartilage. Muscular tissue is responsible for body movement and has two types - voluntary muscle like skeletal muscle, and involuntary muscle such as smooth and cardiac muscle. Nervous tissue is made of neurons and regulates and controls the body.