How does the pancreas control blood sugar levels?

In humans, the pancreas can sometimes be described as an endocrine gland. This means it releases some of its substances staight into the bloodstream; this is the mechanism used to secrete the hormones controlling blood sugar. If we zoom into a pancreas, we can see tissue made of sections called the 'Islets of Langerhans'. The outer surface is lined with cells that secrete digestive enzymes and tubules leading to the main pancreatic duct (exocrine function). Within the islet there are alpha and beta cells, along with capillaries (this is the route through which hormones enter the blood). High blood sugar levels are detected by beta cells, which release insulin. Insulin travels in the blood to various target cells (in the liver, muscle and brain). Insulin works by: 1) activating adenyl cyclase (which converts ATP to cAMP); this will increase glycogenesis (conversion of glucose to glycogen) in the cells, 2) increasing conversion of glucose into fats and 3) increasing the consumption of glucose via respiration, 4) increasing glucose channels in cell membranes. These all act to reduce the circulating blood glucose concentration If the blood sugar levels are too low, this is detected by the alpha cells. The alpha cells will release glucagon in response to this, which act on target cells in the liver. Glucagon 1) promotes the conversion of glycogen into glucose, 2) increases the consumption of fatty acids in respiration and 3) increases gluconeogenesis (conversion of amino acids and fats into glucose). An easy way to remember when insulin and glucagon are released: when there is too much glucose IN the body, we release INsulin. When the glucose is almost GONE, we release glucaGON(E)