The duodenum (part bezbryzheechnaya)
The duodenum (duodenum) is for privratnikovoy (pyloric) part of the stomach and arched crown covers the pancreas. Its length is 25-27 cm It starts from the pylorus at the level of the body XII thoracic or lumbar vertebrae I and ends at the level II-III lumbar vertebrae.
In the duodenum secrete the upper part (pars superior), which is the primary department, the descending portion (pars descendens), horizontal, or bottom part (pars horizontalis), which passes into the ascending portion (pars ascendens). The upper part of the upper square is adjacent to the lobe of the liver, and lower - to the head of the pancreas. The downward part is along the right edge of the phone I-III lumbar vertebrae. Behind it fits right kidney and the lower hollow Vienna, and in front - the root of the mesentery of the transverse colon and right flexure. On the large duodenal papilla in the descending portion of the common mouth of the open pancreatic duct and common bile duct. In passing the upper part is formed into a downward bend the upper duodenum (flexura duodeni superior). The lower part is nearly horizontal, what is the reason her name. In front it crosses the inferior vena cava. In passing downward into the lower part is formed the lower curve of the duodenum (flexura duodeni inferior). The rising part on the bias is directed upwards, passing in front of the abdominal aorta, and passes into the jejunum, forming a sharp bend of the duodenum (flexura duodenojejunalis).
The wall of the duodenum consists of three layers. The outer serosa (peritoneum) covering her from the front only. The average muscle membrane has a thickness of 0.5 mm and is formed by two layers of smooth muscle: an outer - longitudinal and inner - circular (circular). The mucosa is lined single-layered prismatic epithelium with striated border. It forms a circular folds (plicae circulares), whose surface is covered with digitiform appendages - the intestinal villi (villi intestinales). Their number is up to 40 villi in 1 mm2, which gives the duodenum velvety appearance. In the duodenum contains characteristic only for its complex tubular-alveolar duodenum (brunnerovy) cancer (glandulae duodenales), which lie in the submucosa of the upper part of the body, and intestinal crypt tube (liberkyunovy gland), located at the bottom of the depth of the mucosa.
Digestive processes occurring in the duodenum, largely carried out by products of the liver and pancreas.
|In Fig. 163.
Villi of the ileum
1 - epithelium;
2 - blockade the cell;
3 - central lymphatic capillary;
4 - a network of blood capillaries;
5 - the inner layer of a network of blood and lymph vessels;
6 - lymphatic follicle
a., aa. — arteria, arteriae (artery, the artery)
lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)
m., mm. — musculus, musculi (muscle, the muscle)
n., nn. — nervus, nervi (nerve, the nerve)
r., rr. — ramus, rami (branch)
s. — seu (or)
v., vv. — vena, venae (vienna)