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THE ABDOMEN

The abdomen is a cavity containing the main organs of digestion. It is immediately below the chest but separated from it by the diaphragm.

The stomach lies just below the diaphragm and receives all the food which has passed down the oesophagus after being swallowed. Food stays in the stomach for a few hours while the stomach enzymes begin the first stages of digestion.

After leaving the stomach, the partially digested food enters the small intestine. This is a long coiled tube about six metres long in which digestion is completed. It manufactures its own enzymes for this purpose but also receives some help from the pancreas. This gland lies in the loop of the duodenum, which is the first part of the small intestine after the stomach. The pancreas produces some enzymes which pass into the duodenum.

When the food has been completely digested in the small intestine, the indigestible residue passes into the large intestine. This is a wider tube, nearly two metres long, leading from the small intestine to the rectum. The large intestine absorbs water and minerals from waste food remnants. The rectum carries this waste to the external orifice or anus where it is eliminated from the body. The whole system of tubes through which the food passes on its way from mouth to anus is called the alimentary canal.

After digestion has been completed in the intestines, the digested food, which is now in a state the body can use, passes through the walls of the intestines into capillaries where the blood carries it to the liver.

The liver lies just below the diaphragm to the right of the stomach. It is a storehouse for digested food and distributes it to those parts of the body requiring it. It also produces a digestive juice known as bile. This is stored in the gall – bladder, which lies underneath the liver. Bile passes into the duodenum at the same point as the digestive juice from the pancreas.

The next stage of digestion occurs in the stomach, which produces a mixture of acid and enzymes called gastric juice. The acid kills germs and extracts any iron from the food – for haemoglobin formation. The enzymes initiate digestion of proteins and fat.

Food is churned up in the gastric juice for up to five hours before being released into the duodenum. That is why patients must not eat for at least four hours before receiving a general anaesthetic. If such precautions were not taken, the stomach might still contain food which could be vomited during anesthesia and cause blockage of the airway. It must be remembered that the protective mechanism of swallowing, which prevents food entering the airway, may be paralyzed during general anesthesia.

NOTES

1. immediately below – непосредственно под

2. for this purpose – для этого

3. in a state the body can use – в том виде, который приемлем для организма

4. to those parts of the body requiring it – между теми органами, которым она нужна

5. at the same point as – в том же месте, что и …


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