If you have ever held your breath under water, the body used the circulatory, respiratory, and nervous systems to see how long you could manage without fresh air. The nervous system slowed down the respiratory system, which normally keeps the circulatory system oxygenated and running smoothly. The human body consists of eleven organ systems, but these three systems have a unique everyday connection.The circulatory systems job is to pump blood through the body. The circulatory systems has three parts. A network of blood vessels reaches out to the entire body. The blood and the other fluids help the signals or food flow to where they need to be. Lastly, the heart, the main organ, has to pump the blood. Organs do an important job, but they wouldn’t be able to do their job without the heart; therefore, the heart is really important.The heart, supplies the blood that the body needs. Some people may think the heart is large because it has such a big job, but really it’s only the size of a fist. The heart’s valves are opened by the ventricles which lead out into the arteries and into the body. The blood eventually gets to the lungs and brain. The heart is the biggest organ in the circulatory system. This cycle only takes four fifths of a second and involves six whole tablespoons of blood! The heart isn’t shaped like a heart someone would draw on valentine’s day, it looks like an oval with a bunch of tubes going through it and surrounding it. The heart is located in the middle of the body in between the two lungs and behind the sternum so this organ can be protected. The heart, like other major organ produces a key component to the entire body.If we didn’t have the respiratory system we wouldn’t have a working body. This system is in control of getting oxygen to the body. This is also known as the breathing cycle. The respiratory system’s largest organ are the lungs, but has many other key components. When a human takes a breath, the air goes down through the throat, through the trachea and the trachea filters the air. The trachea branches into two bronchial tubes that lead to the lungs. When someone breath out the body is releasing the carbon dioxide and sending the oxygen to the body. The respiratory system makes sure that the lungs have oxygen so that the blood can be oxygenated to.Lungs are what we use to breath and what the respiratory system uses to create oxygen for the whole body. The lungs are the only organs in the human body to float on water, because of the air space they have. The lung’s job is just as important as the heart’s. The heart, like the lungs, produces an element to the entire body: blood. The lungs produce oxygen. These two organs are alike in many ways. The lungs oxygenate the blood so the blood can do its job and to carry oxygen to other parts of the body. The Nerve system, also known as the Nervous system is in control of what the body’s actions are. Not how the body functions, but how the body moves, thinks and speaks. This systems main job is to give orders to the body parts and organs. People don’t realize the brain is giving the commands out because the cycle happens so fast. The commands get sent through nerves and the bloodstream carries the nerves to the correct spot. The brain sends out signals to the body which are carried out by neurons and into the bloodstream. A neuron is a cell which is a must have to the nervous system. Neurons are structured to transmit information throughout the body. The neurons are sent through the bloodstream. Whenever the brain remembers a memory or fact, the neurons have a connection. The brain is protected by the skull and has three separate parts: the forebrain, midbrain, and hindbrain. The three systems act in similar ways. The brain’s main job is to send our signals to the body.The spinal cord, or the spine plays a big part in this system. The spine does two main things. The spinal cord is a pathway for messages sent by the brain to the body, and is also a minor coordinating spot for our reflexes. The spine and the brain are what is known as the central nervous system. The spine is the base of our back and contains 33 parts, or vertebrae. Vertebrae are little connected bones which make up the spinal cord. The spine is what is holding the body’s torso upright. The spinal cord is a key component in the nervous system.The circulatory and the respiratory system work together to keep the body flowing, without these two systems we wouldn’t have the blood or oxygen our body needs. The lungs produce oxygen, and the heart pumps blood. The blood needs to be oxygenated by the lungs. After the blood is oxygenated, the bloodstream has a job: to carry food, bacteria, oxygen, or cells throughout the body. They work together to create the blood that the rest of the body needs. The blood from the circulatory system and the air form the respiratory system work together to make the bloodstream healthy and strong. The brain monitors the respiratory gas levels when these two systems work together. The nervous and the respiratory system work in a way different from the circulatory and the respiratory or the circulatory and the nervous system. The brain tells sends a signal to the lungs telling the lungs to take a breath. The lungs take a breath and get the oxygen that is needed, and exhale the carbon dioxide out of the body. The oxygen gets sent out to the body and the process repeats. When someone breath the nerves from the brain are incorporated in the process just like the circulatory system is too. The circulatory and the nervous system go together to create the blood that the body needs The circulatory, respiratory and the nervous system make a strong connection. The brain sends out a signal carried out by a neuron that tells the lungs to take a breath, the air travels to the lungs. The lungs differenciate the good air from the bad air and the body exhales the bad air out. The air that the lungs didn’t let go of becomes oxygen and goes to the blood from the heart. The heart pumps the blood that gets oxygenated by the oxygen. These three come together to to produce a key component for the body: blood, oxygen and commands. References Chudler, E. H. (1996). Neuroscience For Kids. Retrieved January 5, 2018, from https://faculty.washington.edu/chudler/organ.htmlEssenfeld, Bernice. “Brain.” The Gale Encyclopedia of Science, edited by K. Lee Lerner and Brenda Wilmoth Lerner, 5th ed., Gale, 2014. Science in Context, http://link.galegroup.com/apps/doc/CV2644030334/SCIC?u=nape28931&xid=9759b482. Accessed 22 Dec. 2017.Goserud, E. J. (2003). What Is the Connection between the Nervous System and Respiratory System? 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