How do all the body systems interact with each other?
Our body carries out a large number of processes continuously, even when we are sleeping. These processes may be dependent on each other and work together in concert. Our central nervous system (CNS) controls many of these processes. In fact, our brain is the main information and decision center. It receives information from various parts of our body and it interprets the information and decides on a course of action, finally sending a decision, thereby having control over the function of the body parts. Think about what happens when we touch a hot surface. The skin cells feel the heat, which generates a signal to our brain that generates a response and we move our hand away. Similarly, we eat food and it gets digested by the digestive system, using the oxygen gained from the respiratory system. The circulatory system transfers metabolic products and waste materials to requisite parts of our body. We also get a brain signal to stop eating, since we are feeling full.
Hope this helps.