Английский язык для медиков: конспект лекций - Страница 34

The amount of iron in the body is regulated by control of absorption, since excretion is very small. The amount of iron absorbed from food differs with different foodstuffs, so the com position of the diet is important. Absorption can be increased in the normal Individual when the blood-hemoglobin is lower than normal and is the iron stores are low. Iron stores are normally lower in women than men and so they tend to absorb more iron. Iron absorption can decrease in older persons, especially in those over 60. Many estimates have agreed that the average Western diet pro vides between 10 and 15 mg. of iron daily, of which only 5-10% is absorbed.

Iron absorption takes place mainly in the upper jejunum, though some is absorbed in all parts of the small intestine and even in the colon. Iron in food is mostly in ferric form and must bе reduced to the ferrous form before it can be absorbed; this reduction begins in the stomach – though very little is absorbed there – and continues in the small intestine. The iron is absorbed via the brush-border of the intestine and then may take one of two paths; it is either passed into the blood, where it combines with a globulin, and passes to the marrow or to storage sites; or it combines with the protein, which is then deposited in the intes ti-nal cells.

Iron is lost mostly through the gastrointestinal tract by way of red cells and intestinal cells containing iron lost in the constant desquama-tion from the intestinal mucosa.

Fat factor

An enzyme abnormality has been discovered in the red blood cells of people who are overweight. It's the first clue that obe sity in humans may bе caused by a biochemical defect – not simply by overeating.

Researchers found that obese people have lower levels of a special enzyme that functions as a pump, transporting potassium and sodium in and out of cells. They suggest that with low levels of this pumping enzyme, less energy is used. Thus fewer calories are burned up as heat, while more are stored as fat.

New words

act – акт three – три

stage – стадия

first – начальный

voluntary control – добровольный контроль

soft – мягкий

mass – масса

mastication – перетирание

position – положение

root – корень

lingual muscles – языковые мускулы

second – секунда

brief – резюме

occupied – занятый

guiding – руководство

movements – движения

purely – просто

nature – природа

seized – захваченный

peristaltic – перистальтический

wave – волна

traveling – путешествие

along – вперед

before – прежде

cardiac sphincter – сердечный клапан

total – общее количество

amount – количество

iron – железо

varying – изменение

hemoglobin – гемоглобин

storage – хранение

myоglobin – миоглобин

fraction – фракция

together – вместе

body-weight – масса тела

Present Perfect Tense (действие, совершившееся в прошлом, связано с настоящим).

Спряжение глагола to write в Present Perfect Tense Таблица 13

Запомните типичные для Present Perfect обстоятельства: already, not yet, just, ever, never.

Сравните также:

I have bought a book today (this week, this month) – неистекший отрезок времени – Present Perfect.

I bought a book yesterday (last week, last month) – истекший отрезок времени – Past Simple.

Запомните также следующие предложения.

I have never been to France.

Have you ever been to London?

I haven't seen you for ages.

I haven't met him for a long time.

I haven't been to Moscow since last year.

В следующих предложениях измените время глагола на Present Perfect. Переведите предложения на русский язык

1. I am eating my breakfast.

2. We are drinking water.

3. He is bringing them some meat and veg etables.

4. You are putting the dishes on the table.

5. They are having tea.

6. She is taking the dirty plates from the table.

7. The children are putting on their coats.

8. The pupils are writing a dictation.

9. My friend is helping me to solve a difficult problem.

10. I am learning a poem.

11. She is telling them an interesting story.

12. Kate is sweeping the floor.

13. The waiter is putting a bottle of lemonade in front of him.

14. Susan is making a new dress for her birthday party.

15. She is open ing a box of chocolates.

16. They are writing a dictation.

17. I am drawing a picture.

18. She is cooking dinner.

19. We are dancing.

20. They are jumping.

Answer the questions.

1. Into how many stages is the act of swallowing divided?

2. Is the first stage under voluntary control?

3. What is the second stage in the act of swallowing?

4. Through what in the second stage the food is guiding?

5. What does the third stage in the act of swallowing involve?

6. How is the normal position of the empty human stomach?

7. How are shaped the majority of normal stomachs?

8. How can absorption be increased?

9. Who has normally lower stores of iron?

10. Where is iron lost mostly?

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?

Liver, the pancreas and the kidneys are the organs primarily engaged in the intermediary metabolism of the materials resorbed from the gasro – intestinal tract and in the excretion of metabolic waste products. Of these 3 organs the liver performs the most diverse func tions. It acts as the receiving depot and distributing center for the majority of the products of intestinal digestion and plays a major role in the intermediary metabolism of carbohydrates, fats, proteins and purines.

It controls the concentration of cholesterol esters in the blood and utilizes the sterol in the formation of bile acid. The liver takes in the regulation of the blood volume and in water metabolism and distribution. Its secretion, the bile, is necessary for fat diges tion.

The liver is a site for the formation of the proteins of the blood plasma, especially for fibrinogen, and also forms heparin, also forms heparin, carbohydrate which prevents the clotting of the blood. It has important detoxicating functions and guards the organism against toxins of in testinal origin as well as other harmful substances. The liver in its detoxicating functions and manifold metabolic activities may well be соnsidered the most important gland of the body.

New words

liver – печень

pancreas – поджелудочная железа

kidneys – почки

organ – орган

primarily – прежде всего

engaged – вовлеченный

intermediary – промежуточный

metabolism – метаболизм

gasro-intestinal tract – желудочно-кишечный тракт

excretion – выделение

waste – отходы

diverse – разнообразный

func tions – функции depot – отложение

digestion – переваривание

major role – главная роль

cholesterol – холестерин

esters – жиры

sterol – стерин

bile acid – желчная кислота

regulation – регулирование

fat diges tion – переваривание жиров