Answer:
The answer is in image see it you will get all answers.
All I can think of is a scavenger but that's not a scientific term
D. To help oxygen get into blood vessels
The pulmonary structures refers to the organs of the body that are involved in the breathing process. These include the nostril, the oral cavity, the trachea, the two lungs, etc. Humans take oxygen from the environment to facilitate the respiratory process, at the same time they release carbon dioxide to the environment using the pulmonary structures.
