How does the pancreas affect levels of glucose in the body?

The pancreas is a gland consisting of both exocrine and endocrine tissue. It is responsible for secreting enzymes which are involved in the homeostatic control of blood glucose. In between sections of exocrine tissue there is endocrine tissue organised into areas known as "islets of Langerhans". Within these islets there are two types of cells- alpha and beta. When blood glucose is low (e.g. after exercise), alpha cells produce the hormone glucagon and release this into the blood. This causes glycogen to be converted to glucose and also increases the conversion of amino acids and fats to glucose, resulting in an overall increase in blood glucose. Conversely, when blood glucose is too high (e.g. after a carbohydrate-rich meal) this stimulates beta cells to secrete the hormone insulin. When insulin is released, glucose uptake in cells is increased, more glucose is used in respiration and glucose conversion from glycogen/fats is inhibited. The combination of these processes causes blood glucose levels to drop.