Introduction to Pancreas

Pancreas

In the digestion system, the pancreas plays very important organ and in the circulatory system also. Because pancreas plays the great role to maintain our blood sugar levels. We can consider the gastrointestinal system is the part of the pancreas. The produced digestive enzymes to be released into the small intestine which helps in reducing food particles to basic elements. The reduced food particles should be absorbed by the intestine and these are used by the body. Pancreas have the very different function in which it produces insulin, glucagon and other hormones which are sent into the blood stream which regulates the blood sugar levels and other metabolic activities throughout the body.

The shape of the pancreas is pear and it is approximately 6 inches long. In the middle and back portion of the abdomen, it is located. The first part of the small intestine connects the pancreas, the duodenum, and lies behind the stomach. It is composed of glandular tissue: any substance secreted by the cells of the pancreas will be secreted outside of the organ.

The pancreas secretes the digestive juices and these juices are produced into the duodenum through the Y-shaped duct. It occurs at that point where the common bile duct from the liver and the pancreatic duct join just before the entrance of the duodenum.

The pancreas is the part of the body glands. It has very much significant endocrine function. The islet cells which means small groups of special cells through which the organ make the hormones of insulin and glucagon. These are the hormones which are responsible for regulation of blood sugars. Into the bloodstream, these hormones are secreted directly which affect organs all over the body.

By allowing the sugar to flow into cells the insulin helps to lower blood sugar levels. The glucagon helps to raise blood sugar levels. It releases glucose from its storage sites into the circulation. Insulin and glucagon work opposite to each other but it helps in balancing fashion to keeping blood sugar levels stable.

For maintainance of good health by preventing malnutrition, and controling normal levels of blood sugar a healthy working pancreas in the human body is necessary. The enzymes which are produced by the pancreas needs digestive tract which helps to reduce food particles to their simplest elements, or the nutrients which are not able to absorb. Carbohydrates must be broken down into individual sugar molecules. The reduction of proteins to simple amino acids must be important. The fats should be broken down into fatty acids. In all these transformations the pancreatic enzymes plays very significant role. It is easy to transport the basic particles into the cells that line the intestine, and from there they can be further altered and transported to different tissues in the body as fuel sources and construction materials. Without the balanced action of insulin and glucagon, the body is not able to maintain normal blood sugar levels.

Both exocrine and endocrine cells are consists by the pancreas. Groups of endocrine cells, the islets of Langerhans, secrete two hormones. Insulin is secreted by the beta cells and the glucagon is secreted by the alpha cells. The opposing action of these two hormones determines the level of sugar in the blood.

The concentration of glucose in the blood is decreased by insulin. Into the cells of the liver and skeletal muscles, most of the glucose enters. In these cells, this monosaccharide is converted to the polysaccharide glycogen. Therefore, insulin stimulates the glycogenesis or glycogen formation, stimulating the breakdown of glycogen into glucose for release into the blood.

The development of diabetes mellitus, specifically types I, juvenile diabetes leads by a deficiency of insulin. If the pancreas is not able to produce enough insulin, it can be treated by insulin injections. In type II or maturity onset diabetes, the pancreas does produce enough insulin, but the target cells do not respond to it.

The pancreas has both endocrine and exocrine functions so that it is generally known as a mixed gland. The digestive enzymes into the duodenum through the pancreatic duct is secreted by the exocrine portion. The insulin and glucagon are the two hormones secreted by the endocrine portion, into the blood.

The insulin that types of hormone which can acts directly or indirectly on most of the tissues of the body, except the brain. The uptake of glucose by many tissues, particularly the liver, muscle, and fat is stimulated by the most important action of insulin. The blood glucose should be decreased by the uptake of glucose and increases the availability of glucose for the cellular reactions in which glucose participates. Therefore, the uptake of glucose accentuates the glucose oxidation, fat synthesis, and glycogen synthesis. It is very important to knowing that insulin cannot able to alter glucose uptake by the brain, nor does it influence the active transport of glucose across the renal tubules and gastrointestinal epithelium.

Insulin promotes glycogen synthesis. The activity of the enzyme which catalyzes the rate-limiting step in glycogen synthesis is also increased by it. Triglyceride levels are also increased by insulin by inhibiting triglyceride breakdown, and it also stimulates the production of triglyceride through fatty acid and glycerol phosphate synthesis. The insulin also increases the net protein synthesis, it also stimulates the active membrane transport of amino acids, individually into muscle cells. Other liver enzymes are effected by insulin.

The beta cells secrete insulin, they are situated in the part of the pancreas which is generally known as the islets of Langerhans. That types of groups of cells, which are located randomly throughout the pancreas, also consist of other secretory cells. It is that type of alpha cells which is able to secrete glucagon. The glucagon is that types of hormone which has the following major effects: Pyruvate increases the hepatic synthesis of glucose, lactate, glycerol, and amino acids and the a process is generally called gluconeogenesis, which also raises the plasma glucose level. It should be noted that glucagon has the opposite effects of insulin. Glucagon elevates the plasma glucose, whereas insulin stimulates its uptake and thereby reduces plasma glucose levels; glucagon elevates fatty acid concentrations, whereas insulin converts fatty acids and glycerol into triglycerides, thereby inhibiting triglyceride breakdown.

For regulating the plasma glucose level the alpha and beta cells of the pancreas make up a push-pull system.

References

Dhami, P S, and J K Dhami. A textbook of zoology Vol. II and Vol.III. Latest edition. New Delhi: Pradeep publication, n.d.

Kotpal, R L. Modern textbook of Zoology. Meerut, India: Rastogi Publication, n.d.

Rastogi, S C. Cell, and Molecular biology. New Delhi: New Age International (P) Limited, 2001.

Verma, P S, and V K Agrawal. cell biology,Genetics,Molecular Biology,Evolution, and Ecology. New Dehli, India: S. Chand and company Ltd., 2012.