The cell is the smallest building part of every living being. The simplest plants and animals consist only of one cell. In more complex living beings the cells work together, organized into groups, each of which has its own task.

Tissue is a group of cells of the same species that perform a certain task. There are, for example, bone tissue, etc. Tissues are joined to do a particular job; such a group of tissue is called an organ. For example, the human hand consists of different tissues; bones, muscles, nerves, etc.

There are five important types of cells in the human body. Epithelial or capillary cells build the skin, the glands, and cover the blood vessels. Muscle cells build three types of muscles. Nerve cells constitute the brain, spinal cord, and nerves. The blood cells are in the lymphoma. The connective tissues of the human body form the connective tissue, which is the supporting tissue.