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Урок №8. Пищеварительная система. Digestive system
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Vocabulary:
| Tube - канал alimentary canal – пищеварительный тракт oral cavity – полость рта anus – анальное отверстие digestion – переваривание пищи absorption – рассасывание, поглощение to aid – помогать to producing chemical substance – вырабатывать химические вещества “necessary organs” – необходимые органы “accessory organs” – вспомогательные органы Esophagus – пищевод Stomach – желудок small intestine – малый кишечник large intestine – большой кишечник the upper gastrointestinal tract – верхний отдел ЖКТ the lower gastrointestinal tract – нижний отдел ЖКТ mouth – рот ingested food – поглощенная пища to mix – смешивать gastric juice – желудочный сок to break down food – расщеплять пищу to assimilate – усваивать, поглощать simplified – расщеплен | to absorb nutrients – поглощать, всасывать питательные элементы duodenum – 12- перстная кишка jejunum – тонкая кишка the ileum – подвздошная кишка indigestible food – неусваиваемая пища to eject – выбрасывать, избавляться liver – печень gall bladder – желчный пузырь pancreas – поджелудочная железа salivary glands – слюнные железы teeth – зубы tongue – язык auxiliary organs. – вспомогательные органы bile – желчь protein synthesis – синтез белка to secrete - выделять enzymes – ферменты fats – жиры carbohydrates – углеводы protein – протеины to make insulin – вырабатывать инсулин metabolizing – расщеплять saliva – слюна chewing – процесс жевания swallowing process – процесс глотания deglutition – проглатывание |
Digestive system is the food processing system of human body. The whole digestive system is in the form of a long, hollow, twisted and turned tube, called the alimentary canal, which starts from the oral cavity and ends at the anus. The overall process of digestion and absorption of food occurs in this tube.
Human digestive system consists of the two categories. The first category consists of those organs that are directly involved in the process of digestion and absorption. The second category consists of those organs that aid the process of digestion and absorption of food by producing chemical substances or by some other way. They are not directly involved in the process of digestion and absorption.
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The first category of organs may be called as “ necessary organs ” and the second category as “ accessory organs ”. But without the aid of accessory organs, the process of digestion is seriously impaired. When the accessory organs fail (не в состоянии) to perform their functions completely, the process of digestion may also completely stop.
Necessary Organs Of the digestive system are oral cavity, esophagus, stomach, small intestine, large intestine, anus.
The Necessary Organs Of the human digestive system can be classified into two basic sections: the upper gastrointestinal tract and the lower gastrointestinal tract.
The process of digestion starts in the upper gastrointestinal tract which comprises the mouth, esophagus and the stomach.
Mouth is the first organ that begins the digestion process and it breaks down the food.
The esophagus is a muscular tube that connects the mouth to the stomach. It is around 10 inches long and about 1-inch wide. It passes the food from the mouth to the stomach.
The stomach is the organ that receives the ingested food from the esophagus and mixes it with gastric juices to further break it down.
The lower gastrointestinal tract comprises the small intestine, large intestine and the anus. During digestion the lower gastrointestinal tract helps the body to assimilate all the nutrients that have been simplifie d by the upper gastrointestinal tract.
The small intestine is the longest section of the digestive tract. However, it is called the small intestine because it has a smaller diameter than the large intestine. The main purpose of the small intestine is to absorb nutrients from the food during digestion. It is made up of three parts - the duodenum, jejunum and the ileum.
The large intestine is a highly specialized organ of the digestive system. Its main function is to absorb the remaining water from the indigestible food matter and pass unwanted waste matter from the body.
The anal canal is the last part of the digestive tract. It is located between the rectum and the anus. The main function of the anus is to eject waste matter from the body.
Accessory Organs of the digestive system are liver and gall bladder, pancreas, salivary glands, teeth, tongue.
The human body has some very important organs in the digestive system which can be classified as the auxiliary organs.
The gallbladder stores bile that has been produced by the liver.
The liver is one of the most important organs of the human body. The liver basically performs the task of producing digestive juices, biochemicals and also helps in protein synthesis.
The pancreas secretes enzymes into the duodenum which breaks down the fats, carbohydrates and protein. Another important function of the pancreas is to make insulin that is the chief hormone for metabolizing sugar.
The mouth contains three basic organs - the salivary glands, tongue and the teeth.
Salivary glands: When the mouth receives food, salivary glands secrete saliva, which produces an enzyme that breaks down food. The saliva also contains some properties which kills some of the bacteria.
Tongue helps in the chewing and swallowing process which is also known as deglutition. The tongue guides the food and keeps it between the upper and lower teeth.
Teeth start chewing and breaking food into smaller pieces. Though, the teeth do not play an active role in the chemical simplification of the food, chewing makes it easier for other organs to break down food and absorb nutrients.
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Exercises:
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