Final answer:
The principal artery of the venting system is the pulmonary trunk, which exits the right ventricle and branches into the left and right pulmonary arteries, leading to the pulmonary capillaries involved in gas exchange.
Step-by-step explanation:
The principal artery of the venting system to which branches may be connected is called the pulmonary trunk. This single large vessel exits the right ventricle and at its base has the pulmonary semilunar valve to prevent backflow during diastole. As the pulmonary trunk reaches the superior surface of the heart, it bifurcates into the left and right pulmonary arteries, which then branch many times within the lung.
The pulmonary arteries carry deoxygenated blood to the lungs where they branch into smaller arteries and arterioles leading to the pulmonary capillaries. These capillaries are surrounded by alveoli, the site of gas exchange where blood is oxygenated and carbon dioxide is removed. After oxygenation, the blood returns to the heart via the pulmonary veins, completing the pulmonary circuit.