Part of the gastrointestinal system, the pancreas synthesizes and secretes digestive enzymes in the intestine. It is referred to as a mixed or a heterocrine gland. Since it functions both as endocrine as well as an exocrine gland, it is a dual organ. 99% of the pancreas accounts for exocrine functionalities, while a mere 1% for endocrine.
Pancreas Function – Location of Pancreas
The pancreas is a retroperitoneal structure found on the posterior abdominal wall. It is obliquely placed behind the stomach. It lies in the abdomen and stretches from behind the stomach to the upper left abdomen near the spleen.
The structure can be divided into 4 main parts – head, neck, body and tail. It stretches from the inner curvature of the abdomen at which the head surrounds both blood vessels – the vein and the superior mesenteric artery. The lengthiest part of the pancreas is the body which extends behind the stomach, while its tail terminates next to the spleen.
Pancreas Function – Structure of Pancreas
Appearing as a pinkish-tan structure, the pancreas is a J-shaped organ and distinctly appears lobulated. The connective tissue involved renders septation to give rise to macroscopic lobules that make up the functional units of the exocrine pancreas.
In adult males, this wet structure approximately weighs 100 g, in adult females 85 g while in newborns it weighs about 5 g. The length of the adult gland is about 14 to 18 cm, width is 2 to 9 cm with a thickness of 2 to 3 cm. The structure can be distinguished into 4 main areas – head with the uncinate process, neck, body with tuber omentale and the tail.
Different parts of the Pancreas
- The pancreas’ head is seen in the loop of the duodenum as it leaves the stomach
- The body of the pancreas is seen posterior to the distal part of the stomach between the neck and the tail
- The part of the pancreas seen anterior to the aorta is kind of thin compared to the nearby parts of the head and the body of the pancreas. This area is at times assigned as the neck and indicates the junction of the body and head
- The common bile duct passes through the pancreas’ head and joins the main pancreatic duct, seen near the duodenum. The part which lies closest to the liver in a groove on the dorsal part of the head
Pancreas Function in Digestive system
The pancreas forms a part of the digestive system. At the time of digestion, the pancreas produces the pancreatic juices referred to as enzymes that disintegrate the starches, fats and sugars. The digestive system is assisted by the pancreas in its production of hormones.
The pancreatic juices through the ducts empty into the duodenum. On a daily basis, the pancreas produces close to 8 ounces of juices supplied with enzymes. The enzymes are –
- Protease – it disintegrates the proteins and protects from the entry of germs living in the intestines. At times, the undigested proteins can lead to an allergic reaction in some individuals
- Lipase – these function with the bile produced by the liver to disintegrate the fat. In the absence of lipase, the body finds it difficult to absorb fat and essential fat-soluble vitamins
- Amylase – disintegrates starch into which the body makes use for energy
Inside the pancreas, hormones are produced into the bloodstream and pass messages to the other parts of the digestive system. These hormones are –
- Glucagon – approximately 20% of the cells in the pancreas are constituted by the alpha cells; these produce glucagon. If the blood sugar gets low, glucagon aids in increasing the level by signaling the liver to release the sugar that is reserved
- Insulin – produced in the beta cells of the pancreas, the insulin accounts for 75% of the hormone cells of the pancreas. The hormone assists the body in using sugar for energy requirements. Inadequate levels of insulin cause the sugar levels in the blood to increase, hence developing diabetes
- Amylin and gastrin – in the G cells of the stomach, gastrin is produced, some of it is also made in the pancreas. It triggers the stomach to produce gastric acid. Amylin is synthesized in the beta cells and aids in regulating appetite and emptying the stomach
The pancreas plays a critical role in the functioning of the digestive system. It secretes a fluid containing digestive enzymes into the duodenum. It disintegrates proteins, carbohydrates and lipids. This function is the exocrine function of the pancreas. The cells involved in this function are organized in groups referred to as acini. Cells in each of the acinus are filled with granules containing digestive enzymes, which are secreted as zymogens, their inactive form. The enzyme enterokinase seen in the duodenum lining activates it when it is released into the duodenum. The secretion is influenced by the hormones.
A range of mechanisms functions to make sure that the digestive activities of the pancreas refrain from acting on the digestion of pancreatic tissue itself.
Pancreas Function Insulin
The pancreas is mainly involved in producing the digestive enzymes to disintegrate the ingested food and producing hormones glucagon and insulin to regulate the sugar levels in the body.
Insulin is released from the beta cells in the pancreas when there is a spike in the glucose level in the bloodstream. Once a meal is taken, the carbs ingested are disintegrated into glucose and released into the bloodstream. Then, the pancreas identifies this spike in the blood glucose level and initiates the secretion of insulin.
Insulin functions by enhancing the uptake of the glucose from the blood all through the membranes of the cells into the cells. Hence, glucose is taken out from the bloodstream. Glucose gets used as energy to cells once in cells and utilized for different activities, or is collected in the muscle cells or liver as glycogen. This leads to a drop in the blood glucose level, thereby stimulating the pancreas to turn off the release of insulin.
Function of Pancreas in the Exocrine and Endocrine System
The pancreas has dual roles when it comes to the functions of the body –
- Function in the Exocrine system – the pancreas secretes enzymes in the digestive tract through the duct into the duodenum
- Function in the Endocrine system – the pancreas secretes hormones which include insulin and glucagon – the hormones regulating the blood sugar levels
Function of Pancreas in Exocrine System
The components of the exocrine account for more than 95% of the mass of the pancreas. The role of the pancreas in this system is the secretion of enzymes functioning in tandem with the bile from the liver and the gallbladder, to aid in breaking down the substances for apt absorption and digestion
For digestion, the pancreas produces the following enzymes –
- Trypsin and Chymotrypsin – protein digestion
- Amylase – digestion of carbohydrates
- Lipase – digestion of fats
Pancreas produces enzymes when the food reaches the stomach. These enzymes pass through various ducts to arrive at the pancreatic duct. The key pancreatic duct unites with the common bile duct that carries the bile from the gallbladder and the liver to the duodenum. This juncture is referred to as the Ampulla of Vater. The enzymes from the pancreas and the bile from the gallbladder are poured into the duodenum to aid the digestion of carbs, fats, proteins to be absorbed by the structures of the digestive system.
Function of Pancreas in Endocrine System
The part of the pancreas that produces and secrete hormones – the islets, accounts for about 1-2% of the mass of the pancreas. The role of the pancreas as part of the endocrine system is the secretion of two viral hormones known to regulate the blood sugar level – insulin and glucagon.
Insulin is released by the pancreas when blood glucose level needs to be lowered and when it is too high. On the other hand, glucagon is released by the pancreas to increase the blood glucose level when it is too low.
Maintaining a balance in the blood glucose level in the body is absolutely vital for the proper functioning of the kidneys, liver and brain too. The apt secretion of these hormones is significant for the proper functioning of different systems in the body, including that of the cardiovascular system and nervous system.
Pancreatic juice
The pancreatic juice is a liquid that the pancreas produces and contains several digestive enzymes, such as the elastase, chymotrypsinogen, trypsinogen, pancreatic lipase, carboxypeptidase, amylase and nuclease.
The juice is alkaline as a result of the high concentration of bicarbonate ions. The bicarbonate is used in neutralizing the acidic gastric acid, which enables proper enzymatic changes.
Mainly, the pancreatic juice is governed by the cholecystokinin and secretin hormones produced by the walls of the duodenum and by the activity of the autonomic innervations. The trigger from the entrance of the acidic chyme in the duodenum causes the release of the hormones in the hormones into the bloodstream. Their timely coordination leads to the production of adequate quantities of pancreatic juice into the duodenum, which is enzyme-rich and alkaline in nature.
Additionally, the pancreas gets autonomic innervations. The sympathetic nerve fibres regulate the flow of blood in the pancreas, whereas the parasympathetic neurons trigger the action of the centroacinar and acinar cells.
This was a brief on Pancreas function, location and structure of pancreas, the function of the pancreas in the endocrine and exocrine system.
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