Ukuphefumla kuxa umoya ungena uphuma emiphungeni, okanye i-oxygen xa ihamba ngezinye ii-respiratory organs ezifana nee-gills. Kwii-organisms ezinemiphunga, ukuphefumla kuthiwa yi-ventilation, ezibandakanya zombini i-inhalation ne-exhalation. Ukuphefumla kulelinye lamalungu e- physiological respiration efunekayo ukuze kugcinwe ubomi.