<span>pulmonary veins are among the few veins that carry oxygenated blood instead. Oxygenated blood from the lungs is circulated back to the heart through the pulmonary veins that drain into the left atrium.
hopes this helps you</span>
The role that the mosquito played is that the mosquito was carrying the organism/infection so once it bit Jane, Jane got infected. (Not sure is that’s what your asking but that’s the best I can explain it.)