Gas Exchange in the Lungs

Inside the air sacs, (a)   from the air goes into the blood.

Carbon dioxide from the blood goes into the (a)   .

The process of gases moving between the air and blood is called (a)   .

The tiny air sacs in the lungs are called (a)   .

The walls of the air sacs are very (a)   , allowing gases to move easily.

What comes into the lungs from outside the body?

• Carbon dioxide

• Oxygen

• Nitrogen

• Helium

Which gas moves from the air into the blood?

• Carbon dioxide

• Oxygen

• Nitrogen

• Hydrogen

What is the name of the process where gases move from an area of high concentration to an area of low concentration?

• Respiration

• Circulation

• Diffusion

• Evaporation

In which part of the blood does oxygen combine with hemoglobin?

• White blood cells

• Plasma

• Platelets

• Red blood cells

What separates the air in the alveoli from the blood in the capillaries?

• A thick membrane

• Two very thin cells

• A bone

• A muscle