annular pancreas

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 [pan´kre-as] (pl. pancre´ata) (Gr.)
a large, elongated, racemose gland located transversely behind the stomach, between the spleen and duodenum. (See also Plate 11.) It is composed of both exocrine and endocrine tissue. The acini secrete digestive enzymes, and small ductules leading from the acini secrete sodium bicarbonate solution. The combined product, pancreatic juice, enters a long pancreatic duct and from there is transported through the hepatic duct to the duodenum. The pancreatic juice contains enzymes for the breakdown of proteins, carbohydrates, and fats. The bicarbonate ions in the pancreatic secretion help neutralize the acidic chyme that is passed along from the stomach to the duodenum.

Regulation of pancreatic secretion of enzymes and bicarbonate ions is both neural and hormonal; however, the influences of the hormones secretin and cholecystokinin are more important than vagal stimulation. The entry of chyme into the small intestine causes the transformation of an inactive proenzyme, prosecretin, into active secretin that is released from the mucosa of the upper portion of the duodenum. The composition of the partially digested food entering the duodenum influences the amount of each hormone that is released and, therefore, the characteristics of the pancreatic juice.

The endocrine functions of the pancreas are related to the islets of Langerhans located on the surface of the pancreas. These small islands contain three major types of cells: the alpha, beta, and delta cells. The alpha cells secrete the hormone glucagon, which elevates blood sugar. The beta cells secrete insulin, which affects the metabolism of carbohydrates, proteins, and fats. The delta cells secrete somatostatin, the functions of which are not fully understood, but it is known that it can inhibit the secretion of both glucagon and insulin and may act as a controller of metabolic processes. The somatostatin produced by the delta cells of the pancreas is the same as that produced by the hypothalamus as an inhibitor of the release of growth hormone from the pituitary gland.
Disorders of the Pancreas. Failure of the islets of Langerhans to produce sufficient amounts of insulin results in diabetes mellitus. Disturbances in the exocrine functions of the pancreas produce serious digestive disorders. The pancreas can also be the seat of cancerous growth, and occasionally the pancreatic ducts are blocked by stones. Various factors, not yet fully understood, may result in acute pancreatitis, a condition in which the fluids digest the tissue of the organ itself. cystic fibrosis, a serious congenital disease, is characterized by a deficiency in the secretion of pancreatic juice, and an increase in its viscosity.
The anatomical relations of the pancreas. From Aspinal and Taylor-Robinson, 2001.
annular pancreas a developmental anomaly in which the pancreas forms a ring entirely surrounding the duodenum.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

annular pancreas

An extremely rare finding in which a flat band of pancreatic tissue surrounds the D2 part of the duodenum, causing partial or complete obstruction of the upper GI tract. Complete duodenal obstruction is detectable in the neonatal period, while partial obstruction may remain undetected into adulthood.
Clinical findings
Nausea, vomiting.

Associated anomalies
Duodenal bands, intestinal malrotation, Meckel’s diverticulum, cryptorchidism, cardiac and spinal cord defects; up to 20% have Down syndrome.


Upper GI series, abdominal CT, endoscopy.
Peptic ulcer disease, perforation.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

annular pancreas

An anomalous condition in which a portion of the pancreas encircles the duodenum.
See also: pancreas
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Considering annular pancreas, contrast-enhanced abdominal magnetic resonance imaging (MRI) was performed to support the diagnosis (Picture 3).
Polysplenia syndrome accompanied with situs inversus totalis and annular pancreas in an elderly patient.
Annular pancreas can be either complete or incomplete.
Annular pancreas is a congenital defect, which means it is present from birth.
Duodenal atresia (1) Adeyemi Duodenal atresia, ring (10) of pancreatic tissue surrounding 2nd part Adeyemi Duodenal atresia, annular (10) pancreas around 2nd part of duodenum, mucosal diaphragm Adeyemi Duodenal atresia, complete (10) annular pancreas surrounding duodenum Ruben et al.
On surgical exploration the neonate was found to have situs inversus with duodenal obstruction secondary to annular pancreas. The portal vein was found coursing anterior to the duodenum over the annular pancreas.
Annular pancreas is a rare congenital anomaly that is typically diagnosed in early childhood, either due to symptoms of complete duodenal obstruction and/or frequently associated additional congenital abnormalities.
(7.) Harthun NL, Morse JH, Shaffer HA et al: Duodenal obstruction caused by intraluminal duodenal diverticulum and annular pancreas in an adult.
Whipple's procedure, in our study was done in a patient with annular pancreas. Various procedures were done for pancreatic pseudocyst.
Following mobilization of the duodenum, an annular pancreas, with complete duodenal obstruction, was found.
Annular Pancreas: Only two cases of this anomaly were found during period of study.