Between the avioli and the lungs.
The air sacks which provide the surface through which gas exchange occurs are called alveoli.
Gas exchange occurs in the alveoli in the respiratory system. The thin-walled structures allow diffusion of gases into and out of the capillaries.
Gas exchange does not occur in the respiratory tract, it occurs in the alveoli.
The gas occurs by simple diffusion through the cells.
the alveolus
in the leave
gills
The alveoli at the end of bronchioles allow gas exchange to occur.
gas exchange occurs between the thin walls of the alveoli and the thin walls of the capillaries
in their gills.
In the alveoli
lungs