AEMCA Practice Exam

What occurs in the pulmonary capillary bed during emphysema?

1. Increased blood flow and oxygen exchange

2. Destruction of the capillary bed

3. Enhanced elasticity of blood vessels

4. Improved lung surface area for gas exchange

The correct answer is: Destruction of the capillary bed

In emphysema, one of the hallmark characteristics is the destruction of the alveolar walls and associated capillaries within the lungs. This destruction leads to a decreased surface area for gas exchange because the normal architecture of the lungs is compromised. The pulmonary capillary bed is significantly affected, as the blood vessels that are supposed to facilitate the transfer of oxygen and carbon dioxide are also lost or damaged in this process. In emphysema, the air spaces become enlarged due to the loss of elastic recoil, and with the loss of capillaries, the ability of blood to pick up oxygen from the alveoli is drastically reduced. This ultimately results in impaired gas exchange and reduced oxygenation of the blood, rather than an increase in blood flow or an enhancement in lung functionality. Other options suggested improvements or developments in lung function that are not present in emphysema; in fact, the condition leads to decreased efficiency in those areas.