Английский язык для медиков: конспект лекций
Шрифт:
The large intestine is chiefly concerned with the preparation, storage and evacuation of undigestible and unabsorbable food residue.
New words
process of digestion – процесс переваривания
to begin – начинаться food – пища
to be taken – быть взятым
mouth – рот
diewing – жевание
smaller – меньший
pieces – части
thereby – таким образом
exposing – демонстрация
saliva – слюна
double – двойной
to moisten – увлажнять
facilitating –
contains – содержит
enzyme – фермент
conversion – преобразование
carbohydrates – углеводы
ашкя^ – хотя
action – действие
to pass down – передавать
through – через
stomach – живот
chemical – химикат
physical function – физическая функция
rendered – предоставленный
suitable – подходящий
tongue – язык
rapidly – быстро
equipped – оборудованный
hydrochloric acid – соляная кислота
absorption – поглощение
Спряжение глаголов в Past Simple Tense – правильные глаголы (действие совершалось в прошлом, когда время указано точно).
Спряжение глагола to work в Past Simple Tense Таблица 10
Спряжение глаголов в Past Simple Tense —неправильные глаголы Таблица 11
Перепишите следующий текст, употребив глаголы в прошедшем времени.
On Monday we have five lessons. The first lesson is Russian. At this lesson we write a dictation and do some exercises. Jack goes to the blackboard. He answers well and gets a «five». Pete does not get a «fi-ve'», because he does not know his lesson. After the second lesson I go to the canteen. I eat a sandwich and drink a cup of tea. I do not drink milk. After school I do not go home at once, I go to the library and take a book. Then I go home.
Answer the questions.
1. When the process of digestion begins?
2. What does chewing do?
3. Does saliva have a double function?
4. What does saliva contain?
5. Where does the enzymatic action begin?
6. What functions does the stomach have?
7. What is the most powerful enzyme?
8. What does pepsin begin?
9. By what is the food pushed back into the pharynx?
10. Where the absorption of the product's of digestion also takes place?
Make the sentences of your own using the new words (10 sentences).
Find the verb to be in the text. Explain why it is used in such a way?
ЛЕКЦИЯ № 40. Sources of energy
The fuels of the body are carbohydrates, fats and proteins. These are taken in the diet.
Carbohydrates are the principal source of energy in most diets. They are absorbed into the blood stream in the form of glu cose. Glucose not needed for immediate use is converted into glycogen and stored in the liver. When the blood sugar concentra tion goes down, the liver reconverts some of its stored glycogen into glucose.
Pats make up the second largest source of energy in most diets. They are stored in adipose tissue and round the principal internal organs. If excess carbohydrate is taken in, this can be converted into fat and stored. The stored fat is utilized when the liver is empty of glycogen.
Proteins are essential for the growth and rebuilding of tissue, but they can also be utilized as a source of energy. In some diets, such as the diet of the Eskimo, they form the main source of energy. Proteins are first broken down into amino acids. Then they are absorbed into the blood and pass round the body. Amino acids not used by the body are eventually excreted in the urine in the form of urea. Proteins, unlike-carbohydrates and fats, cannot be stored for future use.
The digestive system, or gastrointestinal tract, begins with the mouth, where food enters the body, and ends with the anus, where solid waste material leaves the body. The primary function of the organs of the digestive system are threefold.
First, complex food material which is taken into the mouth must be digested mechanically and chemically, as it travels through, the gastrointestinal tract.
Second, the digested food must be absorbed by passage through the walls of the small intestine into the blood stream so that the valuable energy-carrying nutrients can travel to all cells of the body.
The third function of the gastrointestinal tract is to eliminate the solid waste materials which are unable to be absorbed by the small intestine.
In the man the food in the mouth is masticated, that is to say it is bitten and broken up by the teeth and rolled into the bolus by the tongue.
The degree of chewing which is possible depends on the jaw articulation, the latter depending on the food. Mastication is voluntary, but it may be reflex, each closure of the jaw acting as a stimulus for their reopening.
After mastication the bolus is swallowed: the swallowing starts as a voluntary movement, but its accomplishment is a chain of reflexes involving the movement of the food by peristalsis, the closure of the nasal and tracheal openings, and the cessation of respiration. Cranial nerves V, IX, and XII are involved.
Peristalsis is a type of muscular contraction characteristic of the gut and consists in waves of contraction, these running along the muscles, both circular and longitudinal, towards the anus.