answers: immune system
context: and is generally very viscous. Mucus is made by two types of specialized cells termed mucus cells in the stomach and goblet cells in the intestines. Signals for increased mucus release include parasympathetic innervations, immune system response and enteric nervous system messengers. Bile is secreted into the duodenum of the small intestine via the common bile duct. It is produced in liver cells and stored in the gall bladder until release during a meal. Bile is formed of three elements: bile salts, bilirubin and cholesterol. Bilirubin is a waste product of the breakdown of hemoglobin. The cholesterol present is secreted </s> Splenic artery The splenic artery (in the past called the lienal artery) is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. The splenic artery gives off branches to the stomach and pancreas before reaching the spleen. Note that the branches of the splenic artery do not reach all the way to the lower part of the greater curvature of the stomach. Instead, that region is supplied by the right gastroepiploic artery, a branch of the gastroduodenal artery. The two gastroepiploic arteries anastomose with each </s> of the pancreas and lies behind the pylorus, at the same level as the transpyloric plane. The "tail" ends by abutting the spleen. The pancreas is a secretory structure with an internal hormonal role (endocrine) and an external digestive role (exocrine). The endocrine part is composed of hormonal tissue distributed along the pancreas in discrete units called islets of Langerhans. Islets of Langerhans have a well-established structure and form density routes through the exocrine tissue. The exocrine part has two main ducts, the main pancreatic duct and the accessory pancreatic duct. These drain enzymes through the ampulla of Vater into
question: the spleen is part of what system in the human body