When air goes down into the lungs, it passes through smaller and smaller tubes and ends up in tiny air sacs called alveoli. Oxygen passes through the walls of the alveoli and enters tiny blood ...

These end in microscopic air sacs called alveoli. The process of ventilation as a series of changes in pressure within the thorax can be modelled using the bell jar model. Parts of the model ...

In the lower lobes and in the lower parts of the upper lobes the changes were more advanced. In these areas the great majority of the alveoli contained concretions (Fig. 6). There was marked ...