The term tissue is used to describe a group of cells that are similar in structure and perform a specific function. The four primary types of tissues in the human body are:

• Epithelial tissue covers the exterior surfaces of the body, line internal cavities and passageways, and form certain glands. Epithlial tissue protects, absorbs, and secretes substances, and detects sensations.
• Connective tissue binds the cells and organs of the body together. Connective tissue provides support and holds body tissues together.
• Muscle tissue has the ability to contract and provides movement.
• Nerve tissue conducts electrical impulses and conveys information from one area of the body to another.