Final answer:
A low flow 0₂ delivery system provides an inspired oxygen concentration of about 21%. Oxygen is supplied from a tank in environments where oxygen is in low supply. The released oxygen mixes with the residual air in the lungs and lowers the partial pressure of oxygen within the alveoli.
Step-by-step explanation:
A low flow 0₂ delivery system provides an inspired oxygen concentration of about 21%. This is because approximately 20% of the atmosphere is oxygen, and the low flow system supplies oxygen from a tank in environments where oxygen is in low supply. The released oxygen mixes with the residual air in the lungs and lowers the partial pressure of oxygen within the alveoli.