The respiratory system uses positive and negative feedback loops. An example of a positive feedback loop is coughing. When you cough you are getting rid of any waste that your body does not need. On the other hand, an example of a negative feedback loop is when you have an increased breathing rate. It commands your breathing and energy that your muscles have to use when you are exercising (Respiratory System, Amy Nicholson). Additionally, homeostasis is maintained in the respiratory system by gas exchange and regulation of blood potential hydrogen or ph (Human Physiology/The Respiratory System). Many things can go wrong in the respiratory system. People can experience asthma, bronchitis, common colds, a cough, cystic fibrosis, laryngitis, tonsillitis, influenza, lung cancer, or pneumonia (Teens Health). There is no way to completely eliminate disease, infection, or illness in the respiratory system, but their are some ways you can decrease the risk of getting one. You can wash your hands often, keep your hands away from your mouth, nose and eyes as much as possible because this is where viruses come from the most. You should also not smoke your use tobacco. You should keep your body fit, so try to exercise regularly. You should most importantly get any vaccines needed to help prevent these sorts of diseases like the flu (Respiratory Problems, Age 12 and Older – Prevention). The circulatory system must keep blood constantly circulating. The main parts are the heart, blood, and blood vessels. The heart is about the size of your fist. It is a muscular pump that keeps the blood circulating through every part of the body. The average adult body contains about 5 liters or more than 5 quarts of blood. About every 60 seconds your blood circulates from your heart, all the way through your body, and back to your heart (Biology textbook, 854). There are three different types of blood vessels in the circulatory system. The “arteries are blood vessels that carry blood away from the heart to the rest of the body.” The “veins are blood vessels that carry blood from the rest of the body back to the heart.” In this picture to the left, it shows that “arteries carry oxygen-rich blood,” which is the red, and “veins carry oxygen-poor blood,” which is the blue. Your blood is not blue, even the oxygen-poor blood. Every part of your body’s blood, oxygen-rich or oxygen-poor is red or a darker red. “Arteries and veins are connected by a system of capillaries. Capillaries are tiny blood vessels that transport blood to and from the cells of the body” (Biology textbook, 855). These vessels are very, very small. The circulatory system can signal positive and negative feedbacks to the body. An example of a negative feedback would be when your body gets too hot, you will start to sweat and when your body gets too cold, you will start to shiver (Heart Circulatory System, Yibelis Abreu). Also, an example of a positive feedback loop would be blood clotting. When “a blood vessel is damaged, chemicals begin a chain reaction that causes platelets to stick to the vessel wall. The platelets release more chemicals that accelerate the clotting process. This process ends once the vessel wall has been repaired by a clot” (Positive Feedback: Blood Clotting). In addition, the circulatory system has two other significant functions that help maintain homeostasis. First, this system gathers waste materials made by digestion and cell metabolism. This gets delivered to the liver and kidneys to be drained out of the body. Second, the circulatory system helps maintain body temperature by dispersing heat that cells generate in the muscles and internal organs (Biology textbook, 855). Many things can go wrong in the circulatory system. People can get congenital heart defects, arrhythmia, heart failure, cardiomyopathy, atherosclerosis, strokes, Abdominal aortic aneurisms, Peripheral artery disease, coronary artery disease, hypercholesterolemia, hypertension, heart attacks, or rheumatic heart disease. There are some ways you can prevent yourself from getting a circulatory disease. You can exercise daily and keep your body at a normal weight. You should not smoking or drink too much alcohol. You should try to keep your stress levels down, and keep a good healthy diet. If you are at risk of any of these conditions you should contact your doctor about how to prevent your blood pressure getting too high, or having high cholesterol levels. Even on how to avoid getting diabetes (Circulatory System Diseases: What You Should Know).In conclusion, the respiratory and circulatory systems are very important in the human body.