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.
Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs and out of the body. Air enters the body through the mouth and nose, from here it moves to the pharynx (throat), passes through the larynx (voice box) and enters the trachea.