The structure of the digestive organs

Starts the alimentary canal, mouth. Here the first working bodies are muscles and teeth. Covering your teeth enamel is the hardest substance in our body. The second group of workers in the mouth are the salivary glands - three pairs of large and many small ones. They produce the first digestive juice - saliva. From every major cancer is a thin tube - duct that opens in the mouth.
After the oral cavity should throat (the name is obviously connected with the word "swallow"), then starts the esophagus. Before throat is the intersection of the respiratory and digestive tracts. In fact, in the back part of the mouth that falls into the throat and called nasopharynx, nasal cavity opens behind actual mouth. Meanwhile, going beyond the respiratory tract - the larynx and trachea , placed ahead of the pharynx and esophagus. So, when swallowing food crosses the respiratory tract. So it is not scored, there are special safety devices. At the time swallowing soft sky closes access to the nasal cavity and the epiglottis and the root of the tongue "overshadow" the entrance to the larynx. If this mechanism is triggered bad, we can poperotsy. In such cases they say that the food was caught in his throat. Measure of protection, which in these circumstances, uses the body, we already know - cough howl reflex.
After 25-inch tube esophagus food enters the stomach is a muscular SAC, in the lining of which is the weight of the smallest pieces of iron, microscopic outputs of which dot the entire mucous membrane. Gland produce these gastric juice is the second order, and one of the most important significance of digestive juice. The man's stomach capacity of 1.5 to 3 liters. The ruminant animals (large and small cattle, horses)drug nutrient-poor vegetarian food, and therefore forced to process the huge amount of it, the capacity of the organs of digestion much more. Abdominal viscera are they up to one third of the volume of the body. In cows, goats and sheep stomach consists of 4 cameras, and the first of them - scar - is like a warehouse for the food which at times brought up back in the mouth and re pereselyaetsya. The capacity of the scar even these relatively small animals, such as goats and sheep, reaches 23 liters! It is 8 times the capacity of a human stomach.
Following after gastric Department of digestive organs are the small intestine, the length of which in humans is about 6 meters. Just twisting and forming many loops, they are placed in the abdominal cavity. Throughout the small intestine as if hanging from the back wall of the abdominal cavity through the mesentery, formed by two layers of the peritoneum, between which go to the intestine vessels and nerves. The initial part of the small intestine has the highest value and is called the duodenum. Near it lies the most important digestive iron - pancreas, duct which flows into the duodenum and is the third of digestive juice. Fourth - intestinal juice is formed in the mass of microscopic pieces of iron, located under the mucous membrane ulcers throughout it. Finally, there is a fifth juice, which, as we shall see, is only of secondary importance. This is bileproduced by the liver and received via a special channel in the duodenum.
Right in the lower part of the abdomen, the small intestine flows into thick. The last as a kind of frame bypasses the entire cavity of the abdomen and enters the rectum, which remove undigested food.
The described device of the digestive system was long known to science. However, their work has been extensively studied only I. P. Pavlov.