Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 77

The respiratory system starts with the nose, continues along the pharynx, larynx, trachea, and bronchi, and ends with the alveoli in the lungs. Oxygenation of blood and carbon dioxide release, the primary duties of the respiratory system, occur in the alveoli of the lungs. Oxygenated haemoglobin in red blood cells supplies oxygen to tissues and binds carbon dioxide in return to release it to the air via the alveoli.

The maximum capacity of the lung is achieved in young adulthood; subsequently, both capacity and lung function start to decline. The respiratory reserve is closely associated with achieving maximum lung capacity; therefore, elderly people can face respiratory difficulties even with normal age.⁸⁵ Since the respiratory system is directly open to the atmosphere, it is very susceptible to harm from air pollutants, chemicals, and smoke.^86‐87 Over the course of a lifetime, exposure to these pollutants causes age‐related changes in the respiratory system in addition to intrinsic ageing mechanisms.