The hormones administered by the pancreas are responsible for controlling and manipulating blood glucose levels. The pancreas houses islets responsible for production and secretion of the hormones, glucagon and insulin. Because of this, the pancreas falls under both the endocrine glandular system as well as the exocrine glandular system. The islets which produce these hormones are semi scattered throughout the pancreas and are known as the islets of Langerhans. These particular endocrine functioning structures are typically able to be located in the body and along the tail of the pancreas. Alpha cells and Beta cells are the cells that are known to secrete the hormones within the islets. Glucagon is administered from the Alpha cells and insulin comes from the Beta cells. Gulcagon has an affect on insulin by providing the appropriate stimulus for the liver to convert glycogen into glucose. The Alpha cells are able to respond appropriately to the feedback provided and thus are able to self monitor. High blood sugar, which is also known as hypoglycemia, can be the result of continuous output of glucagon.
Insulin’s function on the human physiology is opposite of its counterpart, glucagon. Insulin is designed to lower the blood sugar in the body. Insulin is the initiating factor that allows blood glucose to the necessary movement through the cell membranes. Muscular cells and adipose cells rely on this movement of glucose for their ability to function. The glucose level within the cell drops as the glucose moves throughout the cell membrane. Insulin is also an initiating factor in the conversion of glucose to glycogen by the cells of the muscles and liver. This action actually assists amino acids into the cells and provides the foundation for the creation of fats and proteins. When Beta cells are incapable of producing the appropriate amount of insulin, diseases such as diabetes occur.
The pancreas is rather soft, created from lobes, Measures about 6 inches long and 1 inch thick, and performs the functions of a mixed gland. Serving both endocrine functions and exocrine functions, the pancreas is serving dual systems. The islets of Langerhans, or pancreatic islets, are the cell clusters responsible for the pancreas’ endocrine functions. Insulin and glucagon are required hormones of the bloodstream to maintain optimal homeostasis. Performing the exocrine functions requires the proper ability to secrete pancreatic juices which aid in digestion. The pancreatic juice is created within the pancreas and immediately released into the pancreatic duct which empties into the duodenum.
The pancreas is positioned snugly up against the greater curvature of the stomach, which runs along the posterior wall of the abdominal cavity. It head is located close to the duodenum, which is expanded over the central body. The tail tapers off near the location of the spleen. The entire organ in retroperitoneal with the exception of the expanded head.
The exocrine secretion units are tucked inside the pancreatic lobules. These secretion units are technically referred to as the pancreatic acini. The endocrine secretion units are found right next to the exocrine secretion units, these are referred to as pancreatic islet cells however. The pancreatic juice is secreted from the acini, and each individual acinus has only one mere layer of epithelial acinar cells which encompass a lumen.
Branches from the celiac plexus are responsible for the innervation of the pancreas. The innervation of the pancreas is segregated by function, the glandular functional portion receives the parasympathetic innervation while sympathetic innervation is held for the blood vessels of the pancreas.
The splenic artery branches off into the pancreatic branch in order to deliver the appropriate blood supply. The splenic artery is a branch from the celiac artery. The pancreatoduodenal artery is a branch derived from the superior mesenteric artery, which also serves the pancreas; blood flow demands. Venous return is naturally through the splenic and superior mesenteric veins. These veins the drain into the hepatic portal vein.