The Respiratory System 1. The main function of the respiratory system is to get oxygen to the blood and to remove carbon dioxide.
2. The organs of the respiratory system are the nose, the larynx, the trachea, bronchi and the lungs
3. The nose can warm and moisten the air and hairs in the nose can filter out dust
4. The trachea is a tube through which the air passes into bronchi.
5. The bronchi carry the air into the lungs.
6. The lungs are the main organs of the respiratory system.
7.. There are 2 lungs in the human body located in the lateral cavities of the chest. The lungs are separated trom each other by mediastinum and are conical in shape. Each lung has the base. apex, two borders and three surfaces. The structure of the flung consists of an external serous coat, the visceral layer of the pleura, a subserous elastic tissue, and the parenchyma or proper substance of the lungs.
8. The weight of the lungs is about 1.350 gr. in the adult male.
10. The physiology of the lungs is associated with their structure.
11. There are 300 mln alveoli in the lungs.
12. The exchange of gases takes place in the alveoli of the lungs. Oxygen passes into the blood and carbon dioxide passes into the atmospheric air.
13. The exchange of oxygen and carbon dioxide is due to the difference of partial pressures of these gases in the alveolar air and in the venous blood.
14. When we breathe in. the external intercostal muscles contract and lift the ribs. The diaphragm also contracts and goes down. The volume of the chest increases. The pressure in the lungs decreases and the atmospheric air passes into the lungs.
15. When we breathe out. the ribs go down, the diaphragm goes up. the volume of the chest decreases, the pressure increases and the air passes from the lungs.
16. The respiratory rate is 16-20 respirations per minute.
17. The vital capacity of the lungs in the male is 3.5-4 liters and in the female 3-3.5 liters.
