The pancreas, located behind the stomach, is involved in the body's ability to use glucose. Within the pancreas, tiny structures called islets of Langerhans secrete hormones into the blood. These islets are composed of several cell types. One cell type, beta cells, release insulin after every meal. Insulin, along with glucose, passes into the blood stream and travels throughout the entire body. Insulin binds to specific receptors located on cells. The binding prompts the opening of glucose gates, allowing glucose to enter the cell. Diabetes is a disease in which the body has trouble using glucose. In type I diabetes, the beta cells are no longer able to produce insulin. In type II diabetes, insulin is produced and binds with the cell's receptors. However, when insulin binds with the receptor, the glucose gates fail to open, preventing the entry of glucose into the cell.