Once inside a cell, glucose is metabolized for energy. Insulin is active in the transport of glucose across plasma membranes, thus increasing cellular glucose uptake. The most important hormone secreted by the islets is insulin. They make up the exocrine portion of the pancreas, which is independent of the islets and secretes through ducts into the small intestine. The cells surrounding the islets secrete digestive juices. These cells make up the endocrine portion of the pancreas. Without treatment, low blood sugar can lead to seizures or loss of consciousness.Scattered throughout the pancreas are small groups of specialized cells called islets, also known as islets of Langerhans (Fig.