How do cells connect to other parts of your body?

You are made up of cells. So are dogs and cats and trees and fish. Everything that lives is made up of cells. They are the basic building blocks of life. But all cells are not the same. Human cells are different from cow cells or tree cells.

Even inside us, the cells are different. Your body alone has about two hundred different kinds of cells. You actually have trillions of cells, made from those two hundred or so kinds of cells. There are brain cells and bone cells and stomach cells. Each kind of cell has its own specific purpose. There are acid secreting cells inside your stomach to help you break down the food you eat, and cells in your intestines that absorb the food that your stomach helped you to break down earlier. All cells from the stomach to the intestines, work together to form a living organism. Some organisms are made up of just one cell, and others, like you, are made up of trillions. Two very important things are needed to keep all cells alive.

Even single celled organisms must have at least these two things. Bacteria is the only exception. First, all cells need organelles (little internal laboratories with lots of chemicals inside). Bacteria actually lack true organelles. Secondly they need a way to transport the products made in those organelle laboratories.