Homeostasis involves maintaining the balance of internal environment. This includes the regulation of blood pH, concentration of carbon dioxide, the concentration of blood glucose, body temperature and water balance. (The internal environment consists of blood and tissue fluids. ) This is done through the nerves of the nervous system and hormones of the endocrine system. The endocrine system consists of glands that release hormones, carried by the blood. The homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms. The control of body temperature, is carried by through the endocrine hypothalamus, it triggers other responses driven through the nerves: the transfer of heat by the blood and action of the sweat glands of the skin arterioles and the presence of shaking or chills. Control of glucose in the blood, is made by and cells of the pancreas, whose secretion of glucagon, and insulin can maintain normal levels. Diabetes type I and type II. People with diabetes have hyperglycemia. There are two main types of diabetes: Type 1 diabetes is usually diagnosed in childhood, but many patients are diagnosed when they are over 20 years.In this disease, the body makes little or no insulin and require daily injections of this hormone. The exact cause is unknown, but genetics, viruses, and autoimmune problems may play a role. Diabetes type 2 : it is far more common than type 1 and corresponds to a majority of all diabetes cases. It usually occurs in adulthood, but is being diagnosed increasingly in younger people. Insulin receptors of the cells fail. Many people with this type of diabetes do not even know they have it in spite of serious illness.