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.
secondary bronchi (location, function). Location: extend from primary bronchi to tertiary bronchi within lungs; right lung has 3, left lung has 2 (corresponding to lobes of lung) Function: conduct air into and out of lobes of lung.