QUESTION 1 Turn to Page 23 of your lab manual. Looking at Figure 2.5 (picture of lung), the net direction of carbon dioxide will be towards the (lung or capillary). The net direction of oxygen will be towards the (lung or capillary). process of diffusion, there is an exchange of oxygen and carbon dioxide between the alveolar sacs and the blood in the capillaries. 1. Draw a heavy arrow on figure 2.5 to indicate the net direction of carbon dioxide movement. Air in alveolar sacs of lungs 1% CO2 20% O2 Blood capillary Blood in the capillary 4% CO2 12% O2 Figure 2.5. Diffusion of oxygen and carbon dioxide. 2. Draw a dotted arrow on figure 2.5 to indicate the net direction of oxygen movement. 23 23