What is different about pulmonary arteries and veins?

Pulmonary arteries:

* Carry deoxygenated blood from the heart to the lungs.

* Have thinner walls than pulmonary veins.

* Are located in the hilum of the lungs.

Pulmonary veins:

* Carry oxygenated blood from the lungs to the heart.

* Have thicker walls than pulmonary arteries.

* Are located on the surface of the lungs.