PANCREAS
Introduction
The pancreas is a large gland located near the duodenum and stomach. It lies obliquely on the posterior abdominal wall, partially to the right and to the left of the median plane. The right end of the pancreas is large and is called the head; located in the abdomen then comes the short and constricted part, the neck, which is continuous with the main part of the gland, the body; and the thin left end of the pancreas is the tail.
Structure
The pancreas is a retroperitoneal gland that is 12-15cm (5-6 inches) long and 2.5cm (l inch) thick. It is present on the posterior of the greater curvature of the stomach. It is divided into a head, neck, body, and tail; and is connected to the duodenum via two ducts. It is positioned such that it remains in a close association with the duodenum, stomach, spleen, inferior vena cava, abdominal aorta, and left kidney. The Head of the pancreas is the expanded portion fitted in the C-shaped duodenum curve; the neck lies just behind the pylorus; the body lies behind the stomach body; the tip of the tail comes in contact with the spleen.
Exocrine cells release pancreatic juices into small ducts which combine to form the two larger ducts, i.e., the pancreatic and the accessory duct. These ducts transfer the juices into the small intestine. The pancreatic duct (or duct of Wirsung) and the common bile duct (from the liver and gallbladder) unites to form the hepatopancreatic ampulla (or ampulla of Vater) which enters the duodenum on an elevation of its mucosa (called major duodenal papilla lying about 10cm inferior to the pyloric sphincter of the stomach). The sphincter of hepatopancreatic ampulla (or sphincter of Oddi) is a group of smooth muscles which regulates the passage of pancreatic juice and bile into the small intestine via hepatopancreatic ampulla. The accessory duct (or duct of Santorini) which also empties the pancreatic juices into the duodenum lies about 2.5cm superior to the hepatopancreatic ampulla.
Small groups of glandular epithelial cells (known as acini) make up the pancreas. About 99% of aciniform the acute pancreatitis exocrine portion of the pancreas, and the acini cells release pancreatic juice. The remaining 1% of acini in the pancreatic islets (or islets of Langerhans), which form the endocrine portion of the pancreas and secrete glucagon, insulin, somatostatin, and pancreatic polypeptide.
Hormones
The pancreas is a partly exocrine and partly endocrine gland, whose main bulk is formed by its exocrine part. The endocrine part is made up of a large number of rounded cells, known as the pancreatic islets or islets of Langerhans. These cells lie embedded in the exocrine part.
The endocrine part of the pancreas synthesizes the following two hormones:
1) Insulin (secreted by the a-cells of islets of Langerhans), and
2) Glucagon (secreted by the ß-cells of islets of Langerhans).
Both the hormones control the blood glucose levels by their opposing actions, i.e.
1) Insulin reduces the blood glucose levels, and
2) Glucagon increases blood glucose levels.
Insulin
Insulin is injected to normalize blood sugar levels in individuals having type I diabetes (a condition in which the body does not produce sufficient insulin, thus fails to control the blood sugar level) and type 2 diabetes (a condition in which the body does not produce hormones or use insulin in a normal way, thus blood sugar level becomes too high). However, injections are recommended only when these conditions do not respond to oral
Functions
Insulin reduces the levels of absorbed nutrients in blood when they rise above the normal level. When these nutrients (especially glucose) are in excess of immediate needs, insulin
1) Acting on cell membranes and stimulating glucose uptake and its use by muscles and connective tissue cells,
3) Increasing glycogenesis (glucose conversion to glycogen) in liver and muscles,
4) Increasing amino acids uptake by cells, and protein synthesis.
5) Promoting lipogenesis (fatty acids synthesis) and fat storage in adipose tissues.
5) Decreasing glycogenolysis, and
6) Preventing protein and fat breakdown, and gluconeogenesis (formation of new sugar from protein).
Glucagon
Glucagon is a peptide hormone, produced by the pancreatic a-cells. Its action is the reverse of insulin, i.e., it increases blood glucose levels.
Functions
1) Glucagon is a glycogenolytic hormone having the highest potency, and it increases blood glucose levels.
2) It is the body's second defense against hypoglycemia in healthy individuals.
3) It stimulates neoglucogenesis in the presence of glucocorticoids and lipolysis in the peripheral tissues, which in turn stimulates ketogenesis.
4) It stimulates insulin secretion from the pancreatic ß-cells and is also involved in insulin secretion after ingestion of glucose.
5) It produces a positive inotropic and chronotropic digestive enzymes action on the heart functions of the pancreas.
Functions
Since the pancreas is an exocrine as well as an endocrine gland, its functions are as follows:
1) Functions of Exocrine Part: The exocrine part of the pancreas is involved in:
i) Digestion of Proteins: The inactive enzyme precursors '(trypsinogen and chymotrypsinogen) are activated by entering kinase chronic pancreatitis enzyme in microvilli to yield active proteolytic enzymes (trypsin and chymotrypsin).
ii) Digestion of Carbohydrates: Pancreatic amylase converts the digestible polysaccharides (starches) to disaccharides by salivary amylase.
iii) Digestion of Fats: Fats are converted to pancreatic cancer to fatty acids and glycerol by lipase. Bile salts emulsify fats, i.e., reduce the globule size to increase the surface area of digested food.
2) Endocrine function of Part: The endocrine part of the pancreas secretes insulin and glucagon, which control the blood glucose levels.
The endocrine system in the human body introduction
The endocrine system consists of glands secreting hormones essential for the maintenance of homeostasis throughout the body. Hormones are chemical messengers that act to control and coordinate different functions of tissue and organs. Various body activities like weight loss growth and development and metabolism are also regulated by hormones. Each hormone is secreted from a particular gland and is distributed to the target tissues via the blood.
Endocrine glands are ductless glands, thus release their products directly into the bloodstream, and are beta cells carried to their target cells. On the other hand, exocrine function glands secrete their products (excluding hormones and other chemical messengers) into the ducts, which are then transported to the bloodstream.
The endocrine system comprises all the endocrine glands of the body. Pituitary, pineal, thyroid, adrenal, pancreas, parathyroid, thymus, and gonads (testis in males and ovary in females) are the endocrine glands found in humans.
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Old knowledge recommended preventing feeding for a handful of days within the hospital to convey your Gallbladder stone treatment to recovery. This is often not practiced. Newer knowledge has recommended that feeding as you tolerate food helps heal the duct gland.
ReplyDeleteAs the inflammation in your duct gland improves and pain symptoms improve, you must begin drinking clear liquids and feeding bland foods. With time, you'll return to your traditional diet.