AskDefine | Define gastric

Dictionary Definition

gastric adj : relating to or involving the stomach; "gastric ulcer" [syn: stomachic, stomachal]

User Contributed Dictionary

English

Adjective

  1. Of or relating to the stomach.

Translations

Of or relating to the stomach

Derived terms

Extensive Definition

In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. The word stomach is derived from the Latin stomachus, which derives from the Greek word stomachos (). The words gastro- and gastric (meaning related to the stomach) are both derived from the Greek word gaster ().

Functions

The stomach is a highly acidic environment due to gastric acid production and secretion which produces a luminal pH range usually between 1 and 2 depending on the species, food intake, time of the day, drug use, and other factors. Combined with digestive enzymes, such an environment is able to break down large molecules (such as from food) to smaller ones so that they can eventually be absorbed from the small intestine. A zymogen called pepsinogen is secreted by chief cells and turns into pepsin under low pH conditions and is a necessity in protein digestion.
The human stomach can produce and secrete about 2.2 to 3 liters of gastric acid per day with basal secretion levels being typically highest in the evening. The stomach can expand to hold between 2-4 liters of food. It is a temporary food storage area, and in the process of digestion, the food goes into the stomach first.
Absorption of vitamin B12 from the small intestine is dependent on conjugation to a glycoprotein called intrinsic factor which is produced by parietal cells of the stomach.
Other functions include absorbing some ions, water, and some lipid soluble compounds such as alcohol, aspirin, and caffeine.

Anatomy of the human stomach

The stomach lies between the esophagus and the duodenum (the first part of the small intestine). It is on the left side of the abdominal cavity. The top of the stomach lies against the diaphragm. Lying beneath the stomach is the pancreas, and the greater omentum which hangs from the greater curvature.
Two smooth muscle valves, or sphincters, keep the contents of the stomach contained. They are the esophageal sphincter (found in the cardiac region) dividing the tract above, and the Pyloric sphincter dividing the stomach from the small intestine.
The stomach is surrounded by parasympathetic (stimulant) and orthosympathetic (inhibitor) plexuses (anterior gastric, posterior, superior and inferior, celiac and myenteric), which regulate both the secretory activity and the motor activity of the muscles.
In humans, the stomach has a volume of about 50 mL when empty. After a meal, it generally expands to hold about 1 liter of food, but can hold as much as 4 liters. When drinking milk it can expand to just under 6 pints, or 3.4 liter.

Sections

The stomach is divided into four sections, each of which has different cells and functions. The sections are:

Blood supply

The lesser curvature of the stomach is supplied by the right gastric artery inferiorly, and the left gastric artery superiorly, which also supplies the cardiac region. The greater curvature is supplied by the right gastroepiploic artery inferiorly and the left gastroepiploic artery superiorly. The fundus of the stomach, and also the upper portion of the greater curvature, are supplied by the short gastric artery.

Histology of the human stomach

Layers

Like the other parts of the gastrointestinal tract, the stomach walls are made of the following layers, from outside to inside:

Glands

The epithelium of the stomach forms deep pits. The glands at these locations are named for the corresponding part of the stomach:

Control of secretion and motility

The movement and the flow of chemicals into the stomach are controlled by both the autonomic nervous system and by the various digestive system hormones:
Other than gastrin, these hormones all act to turn off the stomach action. This is in response to food products in the liver and gall bladder, which have not yet been absorbed. The stomach needs only to push food into the small intestine when the intestine is not busy. While the intestine is full and still digesting food, the stomach acts as storage for food.

Diseases of the stomach

Historically, it was widely believed that the highly acidic environment of the stomach would keep the stomach immune from infection. However, a large number of studies have indicated that most cases of stomach ulcers, gastritis, and stomach cancer are caused by Helicobacter pylori infection.
gastric in Arabic: معدة
gastric in Aymara: Puraka
gastric in Bosnian: Želudac
gastric in Bulgarian: Стомах
gastric in Catalan: Estómac
gastric in Czech: Žaludek
gastric in Danish: Mave
gastric in German: Magen
gastric in Dhivehi: މައިދާ
gastric in Estonian: Magu
gastric in Modern Greek (1453-): Στομάχι
gastric in Spanish: Estómago
gastric in Esperanto: Stomako
gastric in Basque: Urdail
gastric in Persian: معده
gastric in French: Estomac
gastric in Korean: 위 (기관)
gastric in Croatian: Želudac
gastric in Ido: Stomako
gastric in Igbo: Afọ
gastric in Indonesian: Lambung
gastric in Icelandic: Magi
gastric in Italian: Stomaco
gastric in Hebrew: קיבה
gastric in Javanese: Lambung
gastric in Kurdish: Mîde
gastric in Latin: Stomachus
gastric in Lithuanian: Skrandis
gastric in Lingala: Líkundú
gastric in Hungarian: Gyomor
gastric in Macedonian: Желудник
gastric in Marathi: जठर
gastric in Malay (macrolanguage): Perut
gastric in Dutch: Maag
gastric in Japanese: 胃
gastric in Norwegian: Magesekken
gastric in Pangasinan: Eges
gastric in Polish: Żołądek
gastric in Portuguese: Estômago
gastric in Quechua: Hiq'i
gastric in Russian: Желудок человека
gastric in Sicilian: Stòmmacu
gastric in Simple English: Stomach
gastric in Slovak: Žalúdok
gastric in Slovenian: Želodec
gastric in Sundanese: Burih
gastric in Finnish: Mahalaukku
gastric in Swedish: Magsäck
gastric in Tagalog: Sikmura
gastric in Telugu: జీర్ణకోశం
gastric in Thai: กระเพาะอาหาร
gastric in Vietnamese: Dạ dày
gastric in Turkish: Mide
gastric in Ukrainian: Шлунок
gastric in Võro: Mago
gastric in Yiddish: מאגען
gastric in Dimli: Pize
gastric in Chinese: 胃

Synonyms, Antonyms and Related Words

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