3. Работа над грамматикой 30 мин

Неличные формы глагола. Инфинитив. Функции в предложении – Табл 21 на стр 295 учебника. Дополнительно – упражнения на стр 188-190 грам. справочника (Swan, Walter)

4. Краткое изложение содержания текста 25 мин

MASTICATION

The sight, smell, and thought of food may elicit salivary and gastric secretion. These juices cannot be effective, however, before food enters the body and therefore mastication may be considered the first step in digestion. The up-and-down movement of the mandible results in biting by the incision teeth.

After a mouthful has been taken, both up-and-down side-to-side movements enable the molars to crush and break the food into fragments of proper size for swallowing. Particle size may vary up to 12 mm in diameter but generally it is less than 2 mm. After mastication the mass weighs from 3 to 6 grams, about one-fourth of this weight being due to saliva.

The saliva assists in mastication in several ways: by dissolving some of the readily soluble food components; by partly digesting some of starch; by softening the mass of food; by covering the bolus with mucus so as to make it more easily moved about in the mouth.

In man the act of mastication has more significance than the mere grinding of food preparatory to swallowing. While food is being chewed it is moved about in the mouth so that the taste buds are stimulated and odors are released to stimulate the olfactory epithelium. On these stimuli depends much of the satisfaction and pleasure of eating, which in turn initiate the process of gastric secretion.

DIGESTION IN THE MOUTH

Digestion in the mouth is largely mechanical. The food is broken up by the teeth, ground into small particles, and moistened and softened by the saliva. Saliva is slightly alkaline in reaction with a pH between 6.35 and 6.85. The amount secreted in twenty-four hours is about 1300 cc. It consists of 99.5 per cent water and 0.5 per cent total solids. Its chief constituents are water, inorganic salts, mucin, serum albumin and serum globulin, and salivary amylase or ptyalin.

The one chemical change is effected by salivary amylase which acts on the boiled starch changing it to dextrin and possibly to maltose. It is quite unlikely that this change occurs to any extent while the food is in the mouth, but the ptyalin may continue to act on the starch within the bolus of food for some time after it enters the stomach.

Salivary digestion is important in preparing the food for the changes that follow. Saliva dissolves some of the solid substances so that they are brought in contact with the taste buds; thus they stimulate appetite and result in series of reflexes which increase the flow of gastric juice and augment salivary secretion as well. Moistening food with saliva enables it to be rolled into a plastic mass and gives it a lubricant coating which facilitates swallowing.

ABSORPTION

The only substance absorbed from the stomach to any extent is alcohol. Water is quickly passed from the stomach into the intestine, and considerable quantities are there absorbed in a few minutes. But it is only after subjection to digestion in the intestine for several hours that the bulk of the food is taken up into the system.

The semisolid chyme which leaves the stomach is converted into a yellowish fluid of creamy consistence by the action of the bile and pancreatic fluid. From this the fats, in the form of a fine emulsion, are taken up by lymph vessels called "lacteals", and ultimately reach the blood, while sugars, salts, and amino-acids formed from proteins pass directly into the small blood-vessels of the intestine.

The process is facilitated by the extreme unevenness of the intestinal wall, which is folded into many ridges and pockets, while in microscopic structure the surface is covered by fine finger-like processes named "villi" which are bathed in the fluids passing down the intestine. Further absorption is probably assisted by the "leucocytes", or white cells of the blood which are enormously increased in numbers after a meal, and which have the power of wandering out of the blood stream and taking up particles into their substance.

Food materials are absorbed almost exclusively by the small intestine. The large intestine, or colon, absorbs water and salts. The food is passed down the intestine by the contractions of its muscular coat, and finally, the indigestible residue, together with various waste substance excreted from the liver and intestinal walls, is cast out of the body in the stools.

Формы проверки освоения темы.

Лексико-грамматическая работа № 12. 30 мин

Дайте русcкие эквиваленты следующих слов и словосочетаний:

the food undergoes the reduction

the chemical action

the mechanical reduction

mastication

bile

the most powerful influence

the small intestine

to separate

the ultimate purpose

below at the anus

Дайте английские эквиваленты следующих слов и словосочетаний:

пищеварение

пищеварительный канал

грудная и брюшная полость

при помощи слюны

пища, смоченная слюной

химический процесс выполняется

желудочный сок

полезные и бесполезные составные части пищи

всасывающие канальцы

толстый кишечник

а) Выберите предложения, в которых Participle II входит в состав сказуемого, переведите эти предложения

The heart is supplied with blood through the right and left coronary arteries.

The new kidney is transplanted into the lower part of the abdomen.

We use tissues taken from a corpse and kept in a cold place.

Food is digested in the duodenum and passes from the duodenum to the second part, the jejunum.

The salivary glands produce a fluid called saliva which contains important digestive enzymes to chemically break down starches into sugar.

б) Найдите предложения, где употребляется Participle I не в составе сказуемого и переведите эти предложения

1. The glands which pour juices of secretion into the alimentary canal are the salivary glands secreting saliva into the mouth.

2. The researcher is measuring the relative amount of enzymes at present.

3. The analyzer is determining the findings of enzyme concentration now.

4. The capillaries form a network all over the body, and joining together and getting larger they become veins.

Тема №15: “Microbiology ”.

Время изучения темы: 6 часов (Занятия 17-18)

Цель: Научиться использовать активную лексику и грамматику урока для построения устного высказывания на тему: “ Microbiology ”.

Задачи:

1. Освоить лексический минимум.

2. Тренировать грамматический материал.

3. Тренировать навыки перевода текста.

4. Тренировать навыки краткого аннотирования текста

Материал для изучения:

1.Маслова А.М. “Essential English for Medical Students”

2. «Headway» Student`s Book. Intermediate

3. Michael Swan, Catherine Walter. How English Works. A Grammar Practice Book. – Oxford University Press, 1998.

4. Третьяк С.В., Вересина Л.П. English-speaking countries: history and geography. Книга для чтения

Этапы занятий