Pancreatic juice is a liquid secreted by the

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ...

, which contains a number of

digestive enzyme Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of anim ...

s, including

trypsinogen Trypsinogen () is the precursor form (or zymogen) of trypsin, a digestive enzyme. It is produced by the pancreas and found in pancreatic juice, along with amylase, lipase, and chymotrypsinogen. It is cleaved to its active form, trypsin, by ent ...

, chymotrypsinogen,

elastase In molecular biology, elastase is an enzyme from the class of ''proteases (peptidases)'' that break down proteins. In particular, it is a serine protease. Forms and classification Eight human genes exist for elastase: Some bacteria (includin ...

carboxypeptidase A carboxypeptidase ( EC number 3.4.16 - 3.4.18) is a protease enzyme that hydrolyzes (cleaves) a peptide bond at the carboxy-terminal (C-terminal) end of a protein or peptide. This is in contrast to an aminopeptidases, which cleave peptide bonds ...

pancreatic lipase Triglyceride lipases () are a family of lipolytic enzymes that hydrolyse ester linkages of triglycerides. Lipases are widely distributed in animals, plants and prokaryotes. At least three tissue-specific isozymes exist in higher vertebrates, p ...

nucleases A nuclease (also archaically known as nucleodepolymerase or polynucleotidase) is an enzyme capable of cleaving the phosphodiester bonds between nucleotides of nucleic acids. Nucleases variously effect single and double stranded breaks in their t ...

and

amylase An amylase () is an enzyme that catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of ...

. The pancreas is located in the visceral region, and is a major part of the digestive system required for proper digestion and subsequent assimilation of

macronutrient A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excre ...

substances required for living. Pancreatic juice is

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

in nature due to the high concentration of

bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemic ...

ions. Bicarbonate is useful in neutralizing the acidic gastric acid, allowing for effective enzymic changes. Pancreatic juice secretion is principally regulated by the

hormones A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and beh ...

secretin and

cholecystokinin Cholecystokinin (CCK or CCK-PZ; from Greek ''chole'', "bile"; ''cysto'', "sac"; ''kinin'', "move"; hence, ''move the bile-sac (gallbladder)'') is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and ...

, which are produced by the walls of the

duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine m ...

, and by the action of autonomic innervation. The release of these hormones into the blood is stimulated by the entry of the acidic chyme into the duodenum. Their coordinated action results in the secretion of a large volume of pancreatic juice, which is alkaline and enzyme-rich, into the duodenum. The pancreas also receives autonomic innervation. The blood flow into pancreas is regulated by sympathetic nerve fibers, while

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of t ...

neurons stimulate the activity of acinar and centroacinar cells. Pancreatic secretion is an aqueous solution of bicarbonate originating from the duct cells and enzymes originating from the acinar cells. The bicarbonate assists in neutralising the low pH of the chyme coming from the stomach, while the enzymes assist in the breakdown of the proteins, lipids and carbohydrates for further processing and absorption in the intestines. Secretin-stimulated pancreatic juice can be collected during endoscopy and provides an important source for diagnostic biomarkers, allowing detection of pancreatic pathology, especially cancer not yet visible on medical imaging.. Pancreatic juice is secreted into the duodenum through duodenal papillae. Some individuals have also an accessory duct, named accessory pancreatic duct, which may be functional (that is, it also empties the contents of the exocrine pancreas into the duodenum) or non-functional.

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References

Digestive system Endocrine system {{Enzyme-stub