Question

Imagine a pulmonary embolus breaking up and entering the pulmonary artery supplying blood to an entire lobe of the left lung, blocking 75% of the pulmonary arterioles in that lobe. Describe the effects on the arterioles and bronchioles in this lobe in response to this event.

Answer 1

When a blood clot developed in some part if body travels to the lungs and gets dislodged in one of lung blood vessels it results in pulmonary embolism. Pulmonary embolism results is sudden cessation of blood supply to the part of lungs supplied by the affected blood vessel.
When the pulmonary artery supplying an entire lobe of left lung is blocked ift results in occlusion of blood flow to that area. The bronchioles and alveoli will not get enough blood supply of the particular area.
The arterioles in the area will vasoconstrict in response to decreased blood supply. This will increase the resistance in the arterioles.
The reduced blood flow will cause ventilation- perfusion mismatch, hypoxemia and hyperventilation. It will also increase the alveolar dead space. Continued impaired blood supply to the lobe of left lung will result in death of the lung tissue including the brochioles and alveoli leading to pulmonary infarction.