Pancreas – the pancreas contains two kinds of glandular tissue: the exocrine glands produce digestive enzymes, while the endocrine glands, scattered within them as islets, produce hormones.
The exocrine glands secrete the digestive enzymes into the duodenum, and the endocrine glands secrete the hormones into the bloodstream.
The digestive enzymes (e.g. amylase, lipase, trypsin) are secreted by the cells of the acini and released into the duct of the pancreas, known as the pancreatic duct.
From here, through the sphincter of Oddi, the secretion of the pancreas, i.e. pancreatic juice, reaches the duodenum. Amylase digests carbohydrates, lipase digests fats and trypsin digests proteins.
It also secretes large amounts of sodium bicarbonate, which protects both the duodenum and the enzymes of the pancreas, which work in an alkaline environment, from the harmful effects of stomach acid.
It produces three important hormones: insulin, which lowers the blood sugar (glucose) level by increasing the uptake of sugar by cells; glucagon, which raises the blood sugar level by increasing the release of sugar from the liver; and somatostatin, which has a general inhibitory effect in the digestive system.
