Imiphunga yeentaka ayinayo i-alveoli, endaweni yoko zinezigidi ngezigidi zee-para-bronchi. Ezi-para-bronchi ziphela kwiintwana ezincinane zee-capillaries okanye kwiimfikimfelane zemithambo yegazi zize zigqithe kufuphi nemithambo yomzimba ethwala igazi, ukuze i-diffusion ikwazi ukwenzeka zitsho zitshintshiselane ii-oksijini ne-carbon dioxide. I-oksijini ne-carbon dioxide kwimiphunga yeentaka zisoloko zisasazeka egazini nangaphandle kulo, akunjalo kwizilwanyana ezanyisayo kuba i-diffusion yenzeka kuphela kwi-alveoli.