Organs and organ systems in organelles The human body is made up of many different organs and organ systems, made up of billions of cells. Inside these cells are "tiny organs" or organelles. These organelles act in many ways like the organs and systems of the body. To better understand the relationship between them, I will compare and contrast their differences and similarities. The brain is the control center of the human body. It sends and receives messages to the rest of the body. The brain is made up of many different parts, and each part has its own job. The nucleus of a cell is very similar to the brain because it is the control center of the cell. It also sends and receives messages, only through the cell. The core is made up of many other parts, all with special tasks. The brain and nucleus are similar in many ways, but contrast in one primary area. The brain sends messages via neurons and electrical impulses, while the nucleus does so via messenger RNA. The body has a shape to which the muscular and skeletal systems contribute. Bones provide the structure of the body and muscles allow movement. The cell has similar organelles, the cytoplasm and microtubules, which provide the cell with shape. Microtubules are tubular structures that act like bones in humans, giving shape and support to the cell. Cytoplasm is a gel-like substance that holds things in place and limits the movement of organelles in the cell. The main difference between them is the fact that microtubules are not joined by something like a ligament or tendon, and the cytoplasm does not contract like muscles do. The human body's digestive system is made up of several organs that work together to break down food so it can be used in the body. Similar organelles in the cell are the endoplasmic reticulum, ribosomes, and the golgi body. The endoplasmic reticulum is used in the synthesis of molecules that enter the cell. Ribosomes make proteins and send them to places in the cell that need them. The Golgi body is the “packaging site”. All three of these organelles play an important role in the processing of molecules in the cell.