Pylorus
Encyclopedia
The pylorus is the region of the stomach
that connects to the duodenum
(the beginning of the small intestines). It is divided into two parts:
The pyloric sphincter
, or valve
, is a strong ring of smooth muscle at the end of the pyloric canal which lets food pass from the stomach to the duodenum
. It receives sympathetic
innervation from the celiac ganglion.
.
In such conditions as stomach cancer
, tumours may partly block the pyloric canal. A special tube can be implanted surgically to connect the stomach to the duodenum so as to facilitate the passage of food from one to the other. This tube is called a "pyloric stent."
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
that connects to the duodenum
Duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
(the beginning of the small intestines). It is divided into two parts:
- the pyloric antrumPyloric antrumPyloric antrum is the initial portion of the pyloric part of the stomach. It is near the bottom of the stomach, proximal to the pyloric sphincter, which separates the stomach and the duodenum....
, which connects to the body of the stomach. - the pyloric canalPyloric canalThe pyloric canal, also known as the canalis pyloricus, is the opening between the stomach and the small intestine - External links :*...
, which connects to the duodenum.
The pyloric sphincter
Sphincter
A sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...
, or valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
, is a strong ring of smooth muscle at the end of the pyloric canal which lets food pass from the stomach to the duodenum
Duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
. It receives sympathetic
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
innervation from the celiac ganglion.
Medical significance
One medical condition associated with the pylorus is pyloric stenosisPyloric stenosis
Pyloric stenosis is a condition that causes severe vomiting in the first few months of life. There is narrowing of the opening from the stomach to the intestines, due to enlargement of the muscle surrounding this opening , which spasms when the stomach empties...
.
In such conditions as stomach cancer
Stomach cancer
Gastric cancer, commonly referred to as stomach cancer, can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver...
, tumours may partly block the pyloric canal. A special tube can be implanted surgically to connect the stomach to the duodenum so as to facilitate the passage of food from one to the other. This tube is called a "pyloric stent."