And so a tiny portion of the blood goes into the ventricle, meaning this right ventricle can actually now contract. And as it contracts, it develops the wall of the ventricle. So that partially oxygenated blood goes into the left of the right ventricle, the right ventricle contracts, and then it sends that partially oxygenated blood into the pulmonary trunk. So it moves this way, then it moves via this valve system and into the pulmonary trunk. Now, once inside the pulmonary trunk, what happens next? Well, this is the second difference between the fully functional adult heart and this developing fetal heart.