All the systems in the human body are vital to our survival and well-being. If you take away the functions of just one of these systems our whole body will cease to work properly. The main systems of the human body are the nervous, endocrine respiratory, circulatory, immune, digestive, excretory, skeletal, muscular, and the reproductive systems. They all work together in harmony and unison to keep us alive. The nervous and endocrine systems are what control most of the body. The nervous system includes the brain, spinal, cord and nerves. The endocrine system consists of various hormonal glands such as the pituitary. These two systems interact closely since they both have a part in controlling the body. They work together to aid the body in performing its numerous functions and giving it commands. The respiratory and endocrine system works with all the system by controlling their actions and how they perform their tasks. It moves the muscles of the muscular system and controls all motor movements. The endocrine builds up the bones of the skeletal system and produces the hormones that make the reproductive system mature. The nervous system helps the circulatory system by controlling the amount of glucose in blood and blood pressure. It also regulates breathing for the respiratory system. The digestive system is also aided by the sensory nerves in the mouth which help it decide if food should be released back upward. The nervous and endocrine systems are the "control centers" of the body. The respiratory system is also interacts with other organs. It is made up of the lungs, nose, trachea, and mouth. This system supplies the body with a steady flow of oxygen. The respiratory system helps its circulatory counterpart by providing the blood with oxygen. It also rids the blood of carbon dioxide. The brain of the nervous system is also