Материал: Глебова Е.И. - Английский язык для медицинских специалистов, 2012

UNIT II. RESPIRATORY DISEASES

1.Anatomy and physiology of the respiratory system

VOCABULARY and PRONUNCIATION

 READING and SPEAKING

Task 2. Warm-up discussion.

What do you know about the respiratory system? What main parts does it consist of? What’s its role in the body?

Task 3. Read the text and answer the questions.

Structurally the respiratory system consists of the upper and lower respiratory tracts. The upper respiratory tract includes the nose, sinuses, the pharynx, the larynx, and the epiglottis. The lower respiratory tract

25

includes the trachea, two mainstem bronchi, the bronchioles, alveolar ducts and alveoli.

The nose humidifies, warms, and filters inspired air. Sinuses are airfilled cavities within the hollow bones that surround the nasal passages. They provide resonance during speech. Pharynx is a passageway for both the respiratory and digestive tracts. It is divided into nasopharynx, oropharynx, and laryngopharynx. Larynx is commonly called the voice box. It contains two parts of vocal cords, the false and true cords. The epiglottis is a leaf-shaped elastic structure that is attached along one end to the top of the larynx. It prevents food from entering the tracheobronchial tree by closing over the glottis during swallowing.

The trachea is located in front of the esophagus and branches into the right and the left mainstem bronchi. The right bronchus is slightly wider, shorter, and more vertical than the left bronchus. The mainstem bronchi divide into five secondary or lobar bronchi that enter each of the five lobes of the lung. The bronchi are lined with cilia, which propel mucus up and away from the lower airway to the trachea. In the trachea mucus can be expectorated or swallowed.

Bronchioles branch from the secondary bronchi and subdivide into the small terminal and respiratory bronchioles. Acinus is a term used to indicate all the structures distal to terminal bronchiole. Alveolar ducts branch from the respiratory bronchioles. Alveolar sacs, which arise from the ducts, contain clusters of alveoli, which are the basic units of gas exchange. Cells in the walls of the alveoli secrete surfactant, a phospholipid protein that reduces the surface tension in the alveoli. Without surfactant, the alveoli would collapse.

The lungs are located in the pleural cavity in the thorax. The right lung, which is larger than the left one, is divided into three lobes – the upper, middle, and lower lobe. The left lung, which is narrower than the right lung, is divided into two lobes. The lungs are covered with pleura.

26

The parietal pleura lines the inside of the thoracic cavity, including the upper surface of the diaphragm. The visceral pleura covers the pulmonary surfaces. A thin fluid layer, which is produced by the cells, lining the pleura, lubricates the visceral pleura and the parietal pleura. This fluid allows the two layers to glide smoothly and painlessly during respiration.

The respiratory process consists of the phases: inspiration and expiration. During inspiration the diaphragm descends into the abdominal cavity, causing negative pressure in the lungs. The negative pressure draws air from the area of greater pressure, the atmosphere, to the area of lesser pressure, the lungs. In the lungs, air passes through the terminal bronchioles into the alveoli to oxygenate the body tissues. At the end of inspiration, the diaphragm and intercostal muscles relax and the lungs expand. As the lungs expand, the pressure within the lungs becomes greater than the atmospheric pressure, and the air, which contains the cellular waste products of carbon dioxide and water, moves from the alveoli in the lungs to the atmospheric pressure. Expiration is a passive process.

The respiratory system has primary and secondary functions. As for primary function, it provides oxygen for metabolism in the tissues and removes carbon dioxide, the waste products of metabolism. Besides, the respiratory system facilitates smell, produces speech, maintains acid-base balance, body water levels, and heat balance.

1.What does the upper respiratory tract consist of?

2.What are the main parts of the lower respiratory tract?

3.What is the structure of the bronchial tree?

4.How many lobes are there in the right and left lungs?

5.What are the two types of pleura?

6.What do you call the fluid between the two layers of the pleura and what is it for?

27

7.Describe phases of the respiratory process.

8.What are the primary and secondary functions of the respiratory

system?

Task 4. Are these statements true (T) or false (F)? If the statement is false, correct the statement.

1.The right lung consists of three lobes.

2.The left main bronchus is shorter and wider than the right one.

3.There is a thin fluid layer between the visceral pleura and the parietal pleura.

4.The secondary function of the respiratory system is the process of respiration.

5.Inspiration is a passive process.

GRAMMAR

Task 5. Make comparatives and superlatives of the following adjectives and adverbs.

28

 WORD-BUILDING

Task 6. Complete the table with an appropriate noun or a verb. Find all the synonyms in the text.

 WORK IN PAIRS

Task 7. Ask your partner about any medical terms relating to the topic and answer his/her questions.

Example 1. A: How do you say доля легкого in English? B: It’s lobe of the lung.

Example 2. A: What does respiration mean? B: It means дыхание.

Task 8. Complete the sentences.

1.The respiratory system consists of …

2.The upper respiratory tract includes …

29