The goals of respiration are to provide oxygen to the tissues and to remove carbondioxide , to achieve these goals , respiration can be divided into four major functional events , 1. pulmonary ventilation , 2, diffusion of oxygen and carbondioxide between the alveoli and the bloods. 3, transport of oxygen and carbon dioxide in the blood and body fluids to and from the cells , 4, regulation of ventilation and other facets of respiration .
Transmission electron microscope image of a thin section cut through the bronchiolar epithelium of the lung (mouse), which consists of ciliated cells and non-ciliated cells (called Clara cells). Image shows the ciliary microtubules in transverse and oblique section. In the cell apex are the basal bodies that are the anchoring sites for the ciliary axonemes. Note the difference in size and shape between the microvilli and the cilia.