In: Anatomy and Physiology
Pulmonary trunk: The pulmonary trunk is a an important vessel of the human heart which originates from the right ventricle. It divides into the right and left pulmonary arteries, which goes to the lungs. The function of these vessels is to transmit impure blood (oxygen-depleted, carbon dioxide-rich blood) from the right ventricle to the lungs. In the lungs, the blood becomes purified and oxygenated again. It then goes back to the left side of the heart to be distributed throughout the body.
Pulmonary valve: Pulmonary valve occurs at the opening between the right ventricle and the pulmonary trunk that allow blood to leave the heart through the arteries. It is a single-way valve, which mean that blood cannot flow back into the heart through it. The valve is opened by the increased blood pressure in the ventricle during systolic contraction, pushing blood out of the heart and into the artery. It closes when the pressure decreases inside the heart.