A comprehensive concept is a foundation builder. It is a short statement that combines the following four essential elements to form a strong base for your complex novel: (1) genre, (2) main character, (3) opposition, and (4) macro setting. You can arrange these elements, in any order.
The main respiratory surface in humans is the alveoli, which are small air sacs branching off from the bronchioles in the lungs. They are one cell thick and provide a moist and extremely large surface area for gas exchange to occur.t is a passive process (no energy is required) affected by factors such as the surface area available, the distance the gas molecules must diffuse across and the concentration gradient. Gases must first dissolve in a liquid in order to diffuse across a membrane, so all gas exchange systems require a moist environment.
Quick Answer. Gaseous exchange takes place in the lungs' alveoli, which are tiny sacs found at the ends of the terminal bronchioles. The gases that are exchanged are oxygen and carbon dioxide. The gases can be easily exchanged at the level of the alveoli because these sacs are only one or two cells thick and have a great deal of surface area.