The uncinate process is a small part of the

pancreas The pancreas (plural pancreases, or pancreata) is an Organ (anatomy), organ of the Digestion, digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a ...

. The uncinate process is the formed prolongation of the angle of junction of the lower and left lateral borders in the head of the pancreas. The word "uncinate" comes from the Latin "uncinatus", meaning "hooked".

Structure

Development

The pancreas arises as two separate bodies, the dorsal pancreas and the ventral pancreas. The dorsal pancreas appears first, at around day 26, opposite the developing hepatic duct, and grows into the dorsal mesentery. The ventral pancreas develops at the junction of the hepatic duct and the rest of the

foregut The foregut in humans is the anterior part of the alimentary canal, from the distal esophagus to the first half of the duodenum, at the entrance of the bile duct. Beyond the stomach, the foregut is attached to the abdominal walls by mesentery. ...

. During development, differential growth of the wall of the

stomach The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

causes it to rotate to the left, and the

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

and stomach undergo a lot of growth. This makes the two parts of the pancreas rotate around the

duodenum The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest p ...

. They then fuse; the dorsal pancreatic bud becomes the body,

tail The tail is the elongated section at the rear end of a bilaterian animal's body; in general, the term refers to a distinct, flexible appendage extending backwards from the midline of the torso. In vertebrate animals that evolution, evolved to los ...

, and isthmus of the pancreas. The isthmus (also called the central pancreas) is the region of the gland that runs anterior to the superior mesenteric artery; by convention, it divides the right and left sides of the pancreas. The ventral pancreatic bud forms the pancreatic head and uncinate process. The glands continue to develop but the duct systems anastomose. The main pancreatic duct is formed by the fusion of the dorsal and ventral pancreas. The embryology also explains the strange zig-zag course of the main pancreatic duct and the occasional appearance of an accessory pancreatic duct. The uncinate process, unlike the remainder of the organ, passes posteriorly to the

superior mesenteric vein In human anatomy, the superior mesenteric vein (SMV) is a blood vessel that drains blood from the small intestine (jejunum and ileum). Behind the neck of the pancreas, the superior mesenteric vein combines with the splenic vein to form the portal ...

(it can pass posteriorly to the

superior mesenteric artery In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the ...

, but this is less common).

Clinical significance

Sometimes the pancreas fails to develop normally and there may be congenital defects associated with the uncinate process. The uncinate process may split and encircle the duodenum, which is known as an annular pancreas.Drake et al, ''Gray's Anatomy for Students'', Churchill Livingstone/Elsevier (2010), 2nd edition, chapter 4 There is also a common condition called pancreas divisum where the dorsal and ventral pancreas do not fuse properly.

References

External links

* - "The Pancreas" * - "The duodenum and pancreas." * {{DEFAULTSORT:Uncinate Process Of Pancreas Pancreas anatomy