In this video we look at the levels of organization in the body, starting with the chemical level all the way to the organism level. Levels of organization of body structure and function. How are body parts organized and how do they work so well together? In order to understand anatomy it is a good to break things down into levels. We are going to look at 7 levels of organization. The chemical level starts with atoms, which makes up every material thing in the universe including our bodies. Atoms can bond together to form molecules, which are larger chemical groupings, and molecules can combine with more atoms to from macromolecules. The next level of organization in the body is the organelle level. Organelles are tiny organ like things that are in cells. Organelles have specific functions in cells, and they cannot live outside of cells, and without organelles, cells cannot survive. The cellular level is next. Cells are the smallest unit in the body that shows the basic characteristics of life. It is estimated that the body has around 100 trillion cells, and each cell is made up of a membrane, a nucleus, and a cytoplasm that houses the organelles that are required for the cell to function properly. There are many different types of cells in the body that perform different functions in the body. The next level is the tissue level. Tissue is a group of similar cells that developed from the same part of the embryo, and all perform a certain function. Tissue cells are surrounded by the matrix, or nonliving intercellular substances. There are 4 major types of tissue in the body, connective tissue, muscle tissue, nervous tissue and epithelial tissue. Next up is the organ level. Organs are made up of different kinds of tissues that together can perform different functions in the body. Give an example of an organ here, with the different tissue types and what the organ does. The next level of organization in the body is the system level. Systems are comprised of organs, that by working together can perform more complex types of functions in the body. There are 11 major systems in the body, of which we cover in detail later. Many times systems work together to accomplish different needs of the body, such as the respiratory system takes oxygen in, and the cardiovascular system transports the oxygen to various parts of the body. The organism level is at the last level. The overall human organism is made up of all of the previous levels we just covered.