Usage patterns
〈物〉が肺に入るfor something (smoke, air, etc.) to enter the lungs
Smoke got into my lungs and I started coughing.
肺で呼吸するto breathe using the lungs
Humans breathe using their lungs.
肺にダメージを与えるto damage the lungs
Smoking damages the lungs.
肺の検査を受けるto have one's lungs examined
I get my lungs examined regularly.
肺を切除するto surgically remove (part of) a lung
Cancer was found, and he had surgery to remove part of his lung.
Expressions
肺が弱いhaving weak lungs; having a weak chest