Most WHO departments have their own procedures for supporting research in priority areas-these vary from requesting letters of intent to issuing a call for proposals to commissioning research.
In humans and other mammals, the anatomical features of the respiratory system include trachea, bronchi, bronchioles, lungs, and diaphragm. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood.
Bronchitis: Introduction. Bronchitis is a general term for two diseases that cause swelling and irritation (inflammation) of the lower airways of the lungs called the bronchi and the bronchioles. Types of bronchitis include chronic bronchitis and acute bronchitis.