The ampulla of Vater, also known as the or the hepatopancreatic duct, is formed by the union of the
pancreatic duct and the
common bile duct. The ampulla is specifically located at the
major duodenal papilla.
The ampulla of Vater is an important landmark halfway along the second part of the
duodenum that marks the anatomical transition from
foregut to
midgut, and hence the point where the
celiac trunk
The celiac () artery (also spelled ''coeliac''), also known as the celiac trunk or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) in ...
stops supplying the gut and the
superior mesenteric artery takes over.
Structure
The cystic duct leaves the gallbladder and joins with the common hepatic duct to form the common bile duct. This duct subsequently joins with the pancreatic duct; this junction is known as the ampulla of Vater. The pancreatic duct delivers substances such as
bicarbonate
In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula .
Bicarbonate serves a crucial biochemi ...
and
digestive enzymes to the duodenum. The bile from the gallbladder contains salts which emulsify large fat droplets into much smaller units. This provides a large surface area for the lipase enzymes to act on. The bicarbonate neutralises the acidic chyme, creating alkaline conditions for enzymes such as chymotrypsin and amylase to function optimally.
Function
Various
smooth muscle
Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...
sphincters regulate the flow of
bile
Bile (from Latin ''bilis''), or gall, is a dark-green-to-yellowish-brown fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bi ...
and
pancreatic juice through the ampulla: the
sphincter of the pancreatic duct, the
sphincter of the bile duct
A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the hum ...
, and the
sphincter of Oddi.
The sphincter of Oddi controls the introduction of bile and pancreatic secretions into the duodenum, as well as preventing the entry of duodenal contents into the ampulla.
Clinical relevance
Pancreatitis
Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic p ...
can result from a failure of pancreatic secretions to drain properly. One possible cause of impaired drainage of pancreatic juice is blockage of the sphincter of Oddi. A common cause of blockage is a
gallstone in the
common bile duct.
Thomas' sign is the production of silver stools and can be indicative of cancer of the Ampulla of Vater. The silver-colored stool is a combination of the white stool of obstructive jaundice combined with black stool of melena or bleeding. It was first described in the ''British Medical Journal'' by Dr. H. Ogilvie in 1955.
Etymology
The eponymic term "ampulla of Vater" is named after
Abraham Vater
Abraham Vater (9 December 1684 – 18 November 1751) was a German anatomist from Wittenberg.
He received his doctorate in philosophy from the University of Wittenberg in 1706, and his medical degree from the University of Leipzig in 1710. Afterw ...
(1684–1751),
a
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
anatomist who first published a description of it in 1720.
Additional images
File:Gray1100.png, The pancreatic duct.
File:Ultrasound Scan ND 090551 0930550 cr.png, Carcinoma of Ampulla
References
* "Ampulla, hepatopancreatic." ''Stedman's Medical Dictionary, 27th ed.'' (2000).
* Moore, Keith L. and Arthur F. Dalley. ''Clinically Oriented Anatomy, 4th ed.'' (1999).
{{Authority control
Pancreas anatomy
Gallbladder
pl:Brodawka Vatera