The autonomic nervous system is part of the peripheral nervous system, being divided into sympathetic pathways, which prepare the body for action, and parasympathetic pathways, which prepare the body for rest. This automatically regulates the functions of the body and some muscles. Sympathetic pathways modify nervous activity during times of stress, exercise, low blood glucose, excitement, or fear, due to the flight or fight response. These changes can have an effect on homeostasis by increasing heart rate, increasing blood flow, dilating pupils, sweating, releasing glycogen, increasing oxygen intake, and diverting blood flow away from the gastrointestinal tract. The parasympathetic pathways are important for digesting and absorbing nutrients, slowing them down and allowing for a recovery process. The parasympathetic pathways work in the opposite way to the sympathetic pathways, after a stressful situation they stop the release of adrenaline and allow the body to relax by reducing the heart rate, slowing breathing and contracting the pupils. Homeostasis involves the entire body, but some organs have more important roles in maintaining scale balance. The liver and pancreas maintain adequate levels of glucose in the blood, while the kidneys remove metabolic waste products and maintain adequate levels of salt and water in the blood. The skin and liver help maintain body temperature, while the lungs control oxygen and carbon dioxide levels in the blood, and the blood itself transports nutrients and waste products throughout the body. For homeostasis to function, the transportation, respiratory, gastrointestinal, renal, and cardiovascular systems must function together. Homeostasis works primarily through negative feedback, this is where the response of the effectors diminishes the effects of the original stimulus...... middle of paper ...... on the dioxide, within the body, influencing the pH balance of the blood. This will then affect proteins within the body, known as enzymes, which can only function if the surrounding environment is in balance. Any alteration to this environment will prevent the enzymes from functioning effectively. The extra heat produced during metabolic exchange again increases body temperature by influencing enzymes and the heat is then eliminated by sweating. If the body is not kept hydrated during exercise, dehydration will occur, causing the blood to become concentrated. When the blood becomes concentrated, the cells no longer have enough water to function. If homeostasis is not maintained, this will result in disease and even death, since without each functional part of the body working together efficiently, the body cannot perform at a sufficient level. level to maintain survival.