The flat line is the optimal<unk><unk>  level (i.e. the homeostatic set point).<unk><unk>  levels are balanced by the tug-of-war between 2 functionally opposite hormones, glucagon and insulin.<unk><unk>  levels are regulated by negative feedback in order to keep the body in balance. The levels of glucose in the<unk>  are monitored by many tissues, but the cells in the pancreatic islets are among the most well understood and important. Granule docking is an important glucose-dependent step in human insulin secretion that does not work properly in type 2 diabetes. Glucagon If the<unk>  glucose level falls to dangerously low levels (as during very heavy exercise or lack of food for extended periods), the alpha cells of the pancreas release glucagon, a hormone which travels through the<unk>  to the liver, where it binds to glucagon receptors on the surface of liver cells and stimulates them to break down glycogen stored inside the cells into glucose (this process is called glycogenolysis). The cells release the glucose into the<unk> stream, increasing<unk><unk>  levels. Hypoglycemia, the state of having low<unk><unk> , is treated by restoring the<unk>  glucose level to normal by the ingestion or administration of dextrose or carbohydrate foods. It is often self-diagnosed and self-medicated orally by the ingestion of balanced meals. In more severe circumstances, it is treated by injection or infusion of glucagon. Insulin When levels of<unk><unk>  rise, whether as a result of glycogen conversion, or from digestion of a meal, a different hormone is released from beta cells found in the islets of Langerhans in the pancreas. This hormone, insulin, causes the liver to convert more glucose into glycogen (this process is called glycogenesis), and to force about 2/3 of body cells (primarily muscle and fat tissue cells) to take up glucose from the<unk>  through the GLUT4 transporter, thus decreasing<unk><unk> . When insulin binds to the receptors on the cell surface, vesicles containing the GLUT4 transporters come to the plasma membrane and fuse together by the process of endocytosis, thus enabling a facilitated diffusion of glucose into the cell. As soon as the glucose enters the cell, it is phosphorylated into glucose-6-phosphate in order to preserve the concentration gradient so glucose will continue to enter the cell. Insulin also provides signals to several other body systems, and is the chief regulator of metabolic control in humans. There are also several other causes for an increase in<unk><unk>  levels. Among them are the 'stress' hormones such as epinephrine (also known as adrenaline), several of the steroids, infections, trauma, and of course, the ingestion of food. Diabetes mellitus type 1 is caused by insufficient or non-existent production of insulin, while type 2 is primarily due to a decreased response to insulin in the tissues of the body (insulin resistance). Both types of diabetes, if untreated, result in too much glucose remaining in the<unk>  (hyperglycemia) and many of the same complications. Also, too much insulin and/or exercise without enough corresponding food intake in diabetics can result in low<unk><unk>  (hypoglycemia).
Blood sugar regulation
Treatment of cancer
Wound healing
Bleeding
Digestion
Bodily integrity
Drug metabolism
Neuroprotection