Fig. 8. Diagram of lungs.
Lesson 8 ♦ 113
simultaneously with the increase in capacity of the thorax./The lungs
expanding, the air pressure in them drops and atmospheric air rushes
into the lungs through the air passages, ^lence an inhalation involves a
contraction of muscles, an increase in the capacity of the thorax, an
expansion of the lungs, and entrance of atmospheric air into the lungs
through the air passages. { *■
2. Inhalation is followed by exhalation. The muscles participating in inhalation relax, jthe^fapTifagmlismg!]The ribs drop as a result of contraction of the internal intercostar^ahd other muscles and because of their own weight. Jhe capacity of the thorax decreasingjfhe lungs become compressed', ifte pressure in Ihetn rises and the air rushes out through the air passages. ^/
3. The respiratory movements are rhythmic. An adult at rest makes 16-20 respiratory movements per minute, children make more movements (a newborn child makes up to 60 movements a minute)/Physical exertion, particularly in untrained people, is usually accompanied by faster respiration. Accelerated respiration is also observed in many diseases. Sleep is accompanied bwa slowing of respiration.
4. Movements of breathing, (changes in the volume of air in the lungs are brought about by movements both of the diaphragm and ribs^ Contraction of the diaphragm increases the length of the capacity of the chest, while the upward movement of the ribs increases the cross section of the chest. Inspiration is due to contraction of the diaphragm and of the muscles attached to the ribs. These contractions are induced by nervous impulses. Expiration is a less active process than inspiration, for when the muscles relax the elasticity of the lungs themselves tends to drive out the air previously inhaled .'Any impediment to breathing due to pressure or constriction in the respiratory passage^ is especially noticeable during expiration, because it is usually of a passive character. \^Vhen the volume of breathing is increased by physical exercise many ^assessory muscles are involved while producing deeper inspirations. Expiration also involves a Vigorous action of the abdominal muscles. \ \ ^'*ЧЛ ./
■ , ; * л
; - \ < A
Упражнение 9.1) Прочтите и переведите текст А. Первый абзац перевелите письменно. 2) Найдите в тексте А ответы на следующие вопросы и считайте их.
1. How is contraction of the muscles participating in inhalation regulated? 2. Why does the size of the thoracic cavity increase? 3. When is impediment to breathing especially noticeable? 4. What processes does
114<У Learning to Understand a Medical Text
the inhalation (exhalation) involve? 5. What do the movements of the/ diaphragm and ribs bring about?
3) Составьте письменно план текста А. Упражнение10. Подберите пары синонимов.
inspiration, to take place, to induce, per minute, respiration, breathing, to cause, to produce, inhalation, to occur, a minute
Упражнение 11.Подберите пары антонимов.
to compress, inhalation, to contract, to increase, to drop, upward, to decrease, to rise, downward, exhalation, to expand, to relax
Упражнение 12.Переведите следующие предложения, определите функции причастий.
1. For mechanical analysis the respiratory system may be divided into three parts: the gas (in the airways and air spaces), the lung structure, containing the gas, and the thorax containing the lungs. 2. Dynamic increases in airway resistance during expiration set the limit on the ventilatory capacity of the respiratory system in normal and diseased lungs. 3. While flowing through the capillaries the blood accepts the oxygen from the alveolus and deposits carbon dioxide into the alveolus. 4. Airway pressures are not everywhere equal, being most negative in the alveoli. 5. During inspiration pleural pressures become more negative, the widening tendency increasing.
Упражнение13. Переведите на английский язык.
1. Дыхание — это процесс, включающий ритмично повторяющиеся вдох и выдох. 2. На мышцы, которые участвуют в процессе дыхания, воздействуют нервные импульсы. 3. Когда диафрагма опускается, размер грудной клетки увеличивается. 4. Во время выдоха объем грудной клетки уменьшается, идавление в легких увеличивается. 5. Физическая нагрузка обычно сопровождается ускоренным дыханием.
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