First 89 words of the document:
Lungs are adapted through diffusion because of
large surface area due to the shape of the alveoli so more diffusion can take place.
short diffusion distance, alveoli and capillaries lined with squamous epithelium which is 0.5
micrometers, thin for easy diffusion.
moisture so gases can be dissolved in and out of the lungs quickly
lungs maintain steep concentration gradient, maintained by ventilation high oxygen and low
co2, blood circulation supplies co2 and removes o2 .Blood vessels help with inspiration and