Anatomy of Respiratory System

The cells of the human body require a constant stream of oxygen to stay alive. The respiratory system provides oxygen to the body’s cells by removing carbon dioxide.

There are 3 major parts of the respiratory system: the airway, the lungs, and the muscles of respiration.

The airway includes the nose, mouth, pharynx, larynx, trachea, bronchi, and bronchioles.

The nose and nasal cavity form the main external opening for the respiratory system through which air moves. The nasal cavity is a hollow space within the nose and skull that is lined with hairs and mucus membrane which warm, moisturize, and filter air.

The mouth or the oral cavity is the secondary external opening for the respiratory tract. It can be used to supplement or replace the nasal cavity’s functions when needed.

The pharynx, also known as the throat, is a muscular funnel. It extends from the nasal cavity to the larynx and esophagus.

The larynx, also known as the voice box, is a short section between the pharynx and trachea.

The trachea is a tube which extends from the base of the larynx to the lungs, where it divides into two bronchi.

The bronchi are two tubes which begin at the division of the trachea. The left bronchus is slightly longer than the right one as it passes around the heart to reach the left lung. Each bronchus leads into a lung. Inside the lungs, the bronchi divide, and subdivide, into smaller numerous bronchioles. The bronchioles end in very fine alveolar ducts leading to the alveoli.

The alveoli, or air sacs, are the ends of the air passages. Each alveolus is closely surrounded by blood capillaries. There are over 700,000,000 alveoli in the lungs. The total surface of the alveoli is about 90 sq.m (square meters).

The lungs are paired, spongy organs located in the chest. The lungs are divided into lobes - the right lung has three lobes and the smaller left lung has two lobes. Each lung is enclosed in a membranous sac, or pleura. The lungs have many capillaries with the total surface of about 80 sq.m.

It is considered that in the adult the vital capacity of the lungs is about 3-4 liters. When the depth of respiration increases the vital capacity may be 6 litres and even more.

Exercise 6. Find corresponding equivalents:

1. a single bronchiole 2. oral cavity & nasal cavity 3. a hollow space within the nose and skull 4. external opening 5. a short section of the airway 6. to be lined with hairs and mucus membrane 7. to range from … to… 8. to extend from … to… 9. to remove carbon dioxide 10. to be surrounded by blood capillaries

1. коротка ділянка повітряних шляхів 2. простягатися з … до … 3. виводити вуглекислий газ 4. бути оточеним кров’яними капілярами 5. варіюватися від … до … 6. ротова та носова порожнини 7. бути покритим волосками та слизовою оболонкою 8. одна бронхіола 9. порожнина в носі та черепі 10. зовнішній отвір

Exercise 7. Match the terms with their definitions:

1. oral cavity 2. trachea 3. larynx 4. bronchus 5. alveolus 6. lung 7. pleura

a) either of the two main branches of the trachea that lead to the lungs, where they divide into smaller branches; b) a membrane that encloses each lung and lines the chest cavity; c) either of the two saclike respiratory organs in the thorax of humans and the higher vertebrates; d) a tube that connects the pharynx and larynx to the lungs, allowing the passage of air; e) the opening through which food is taken in and vocalizations emerge; f) any of the tiny air-filled sacs arranged in clusters in the lungs, in which the exchange of oxygen and carbon dioxide takes place; g) a muscular and cartilaginous structure lined with mucous membrane at the upper part of the trachea in humans, in which the vocal cords are located.

Exercise 8. Answer the questions:

1. What is the respiratory system responsible for?

2. What are the main parts of the respiratory system?

3. What is the nose covered with?

4. What are pharynx and larynx?

5. Which bronchus is larger and why?

6. How many alveoli are there in the lungs?

7. What are the lungs? What is their vital capacity?

8. What are the common diseases of the respiratory tract?

Exercise 9. Fill in prepositions from the box below where necessary:

With; into; in; of; through; to; out;

1. Respiration is a process which provides body ……. oxygen for growth and other metabolic activities and removes waste products in the form …… carbon dioxide.

2. The lungs are the main organs involved ……… the respiration process.

3. Air passes ……. the lungs …… the nostrils and the air flows down the trachea …….. the lungs.

4. The lungs have alveoli which are small air sacs filled …….. tiny capillaries.

5. The respiration process is carried …….. in two ways in living organisms: aerobic and anaerobic respiration.

6. Some ……. the common diseases related …….. respiration are common cold, tonsillitis and laryngitis.

7. Asthma and pneumonia are diseases associated ……… respiration along with lung cancer.

Exercise 10. Fill in the gaps with the words and word-combinations from the box:

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