The is a
Gland Organ in the
Digestive and
Endocrine System s of vertebrates. It is both
Exocrine (secreting
Pancreatic Juice containing
Digestive Enzyme s) and
Endocrine (producing several important
Hormone s, including
Insulin ,
Glucagon , and
Somatostatin ). It is considered to be the most important intestinal gland.
In humans, the pancreas is a 15-25 cm (6-10 inch) elongated organ in the abdomen. It weighs between 65g - 75g. One of the organs behind the abdominal cavity, it is located posterior to the
Stomach and in close association with the
Duodenum .
It is often described as having four regions: a head, neck, body and tail.
The
Pancreatic Duct (also called the
Duct Of Wirsung ) runs the length of the pancreas and empties into the second part of the duodenum at the
Ampulla Of Vater . The
Common Bile Duct usually joins the pancreatic duct at or near this point.
Many people also have a small accessory duct, the
Duct Of Santorini , which extends from the main duct more upstream (towards the tail) to the duodenum, joining it more
Proximal than the ampulla of Vater.Cutler, Anne G., et al., eds. Stedman's Medical Dictionary. Baltimore: The William and Wilkins Company, 1976 ed.
The pancreas is supplied
Arterially by the
Pancreaticoduodenal Arteries and the splenic artery:
Venous drainage is via the
Pancreaticoduodenal Veins which end up in the
Portal Vein . The
Splenic Vein passes posterior to the pancreas but is said to not drain the pancreas itself. The portal vein is formed by the union of the
Superior Mesenteric Vein and splenic vein posterior to the neck of the pancreas. In some people (some books say 40% of people), the
Inferior Mesenteric Vein also joins with the splenic vein behind the pancreas (in others it simply joins with the superior mesenteric vein instead).
The pancreas is innervated by the
Pancreatic Plexus ; a subdivision of the
Celiac Plexus that accompanies pancreatic arteries.......
Under a microscope, when properly stained, it is easy to distinguish two different tissue types in the pancreas. These regions correspond to the main pancreatic functions:
There are four main types of cells in the
Islets Of Langerhans . They are relatively difficult to distinguish using standard staining techniques, but they can be classified by their secretion:
The islets are a compact collection of endocrine cells arranged in clusters and cords and are crisscrossed by a dense network of capillaries. The capillaries of the islets are lined by layers of
Endocrine cells in direct contact with vessels, and most endocrine cells are in direct contact with blood vessels, by either
Cytoplasm ic processes or by direct apposition. According to the volume ''The Body,'' by
Alan E. Nourse , in the Time-Life Science Library Series, the islets are "busily manufacturing their hormone and generally disregarding the pancreatic cells all around them, as though they were located in some completely different part of the body." (op. cit., p. 171.)
There are two main types of exocrine pancreatic cells, responsible for two main classes of secretions:
Due to the importance of its enzyme contents, injury to the pancreas is potentially very dangerous. A puncture of the pancreas generally requires prompt and experienced medical intervention.
Diseases associated with the pancreas include:
Diabetes Mellitus is a metabolic disorder characterized by
Hyperglycemia . All three forms of the disease are due to the inability of the beta cells of the pancreas to produce sufficient insulin.
Researchers at the Toronto
Hospital For Sick Children injected
Capsaicin into
NOD Mice (Non-obese diabetic mice, a strain that is genetically predisposed to develop the equivalent of
Diabetes Mellitus Type 1 ) to kill the pancreatic
Sensory Nerves . This treatment reduced the development of diabetes mellitus in these mice by 80%, suggesting a link between
Neuropeptides and the development of diabetes. When the researchers injected the pancreas of the diabetic mice with sensory neuropeptide (sP), they were cured of the diabetes for as long as 4 months. Also, insulin resistance (characteristic of
Diabetes Mellitus Type 2 ) was reduced.
Like any other organ, the pancreas is susceptible to the growth of
Benign Tumor s. Benign tumors do not invade neighboring tissues, do not cause
Metastases , and usually do not return after surgical removal.
Pancreatic Cancer is a
Malignant Tumour within the pancreatic gland. Its prognosis is generally regarded as poor. The different types of pancreatic cancers include:
- Tumors of the Centroacinar Cells .
- Pancreatic Exocrine Tumors. Examples include:
- ---Pancreatic Adenocarcinoma . It represents about 95% of all pancreatic tumors. 75% to 96% of all pancreatic adenocarcinomas are ductal cell adenocarcinomas.
- ---Other tumors of the Exocrine pancreas, such as serous cystadenomas.
- Pancreatic Endocrine Tumors (PET's), also known as Endocrine Pancreatic Tumors (EPT's), or Islet Cell Tumors. They are a type of Neuroendocrine Tumors . PET's represent between 1 and 2% of all pancreatic tumors. Between 15 and 30% of all PET's are non-functioning, while 70 to 85% of them are functioning. Examples of functioning PET's include:
- --- Gastrinoma , producing excessive Gastrin and causing Zollinger-Ellison Syndrome (ZES)
- --- Insulinoma , producing excessive insulin
- --- Glucagonoma , producing excessive glucagon
- ---Vasoactive intestinal peptideoma (VIPoma), producing excessive Vasoactive Intestinal Peptide (VIP)
- ---PPoma, producing excessive pancreatic polypeptide (often classed with non-functioning PETs)
- --- Somatostatinoma , producing excessive somatostatin
- ---Watery diarrhea, hypokalemia-achlorhydria (WDHA)
- ---CRHoma, producing excessive Corticotropin-releasing Hormonse (CRH)
- ---Calcitoninoma, producing excessive Calcitonin
- ---GHRHoma, producing excessive Growth-hormone-releasing Hormone (GHRH)
- ---Neurotensinoma, producing excessive Neurotensin
- ---ACTHoma, producing excessive Adrenocorticotropic Hormone (ACTH)
- ---GRFoma, producing excessive Growth-hormone Release Factor (GRF)
- --- Parathyroid Hormone –related peptide tumor
Cystic Fibrosis , also known as , is a hereditary disease that affects the entire body, causing progressive disability and early death. There is no cure for cystic fibrosis, and most affected individuals die young from lung failure. Cystic fibrosis is caused by a
Mutation in a
Gene called the
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). The
Product Of This Gene helps create sweat,
Digestive Juices , and
Mucus . Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis. Cystic fibrosis develops when neither gene works normally. Therefore, it is considered an
Autosomal Recessive disease. The name ''cystic fibrosis'' refers to the characteristic 'fibrosis' (tissue scarring) and cyst formation within the pancreas. Cystic fibrosis causes irreversible damage to the pancreas, which often results in painful inflammation (
Pancreatitis ).
Exocrine Pancreatic Insufficiency (EPI) is the inability to properly digest food due to a lack of
Digestive Enzyme s made by the pancreas. EPI is found in humans afflicted with cystic fibrosis. It is caused by a progressive loss of the pancreatic cells that make digestive enzymes.
Chronic Pancreatitis is the most common cause of EPI in humans. Loss of digestive enzymes leads to
Maldigestion and
Malabsorption of nutrients.
Hemosuccus Pancreaticus , also known as
Pseudohematobilia or
Wirsungorrhage , is a rare cause of
Hemorrhage in the
Gastrointestinal Tract . It is caused by a bleeding source in the pancreas, pancreatic duct, or structures adjacent to the pancreas, such as the
Splenic Artery , that bleed into the pancreatic duct. Patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage, such as blood in the stools, maroon stools, or
Melena . They may also develop abdominal pain. Hemosuccus pancreaticus is associated with
Pancreatitis ,
Pancreatic Cancer and
Aneurysm s of the
Splenic Artery .
Angiography may be used to treat hemosuccus pancreaticus, where the
Celiac Axis is injected to determine the blood vessel that is bleeding, because
Embolization of the end vessel may terminate the hemorrhage. Alternatively, a distal
Pancreatectomy may be required to stop the hemorrhage.
Pancreatitis is
Inflammation of the pancreas. There are three forms of pancreatitis, which are different in causes and symptoms, and require different treatment:
- Acute Pancreatitis : A rapidly-onset inflammation of the pancreas.
- Chronic Pancreatitis : A long-standing inflammation of the pancreas.
- active within the pancreas, which in turn leads to digestion of the pancreas from the inside.
A
Pancreatic Pseudocyst is a circumscribed collection of fluid rich in
Amylase and other pancreatic
Enzyme s, blood and
Necrotic Tissue , typically located in the
Lesser Sac .
The pancreas was first identified by
Herophilus (335-280 BC), a
Greek Anatomist and
Surgeon . Only a few hundred years later,
Ruphos , another Greek anatomist, gave the pancreas its name. The term "pancreas" is derived from the
Greek ''pan'', "all", and ''kreas'', "flesh", probably referring to the organ's homogeneous appearance.
1
Pancreases (specifically calf and lamb pancreases) are used in some meals often going by the name ''stomach
Sweetbreads ''.New Standard Encyclopedia, 1988. Volume P Page 68
Heywood Banks , who performs regularly on the
Bob & Tom Show , recorded a song titled "The Pancreas," composed of doggerel verses that rather accurately, if facetiously, decribe the function of the pancreas. The lyrics include "Let's all sing a tribute to the pancreas...hey pancreas, have a nice day!"
Satiric singer
"Weird Al" Yankovic has recently produced a song titled "Pancreas." It includes many lyrics about the functions of the organ as well as the names of various chemicals it produces, concluding, "I love my pancreas!" The song can be found on his 2006 album "
Straight Outta Lynwood ."
In The Fairly Odd Parents, when Cosmo was Kenny Kidney, Wanda was Penny Pancreas. The residents made references that the pancreas isn't a vital organ.
Italian Opera singer Luciano Pavarotti died of pancreatic cancer at the age of 71 on the 6th of September 2007.
