What is the effect on alveolar surface area and gas exchange of the thinning of alveolar walls and coalescing of alveoli that occurs with aging?Multiple ChoiceA decrease in surface area and increase in gas exchangeAn increase in surface area and increase in gas exchangeA decrease in surface area and decrease in gas exchangeAn increase in surface area and decrease in gas exchange

The correct answer is "A decrease in surface area and decrease in gas exchange".

Here's why:

1. Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. The surface area of these alveoli is crucial for efficient gas exchange.

2. As we age, the walls of the alveoli can thin and the alveoli can coalesce, or merge together. This reduces the total surface area available for gas exchange.

3. With less surface area, there is less space for oxygen and carbon dioxide to be exchanged. This leads to a decrease in gas exchange efficiency.

4. Therefore, the thinning of alveolar walls and coalescing of alveoli that occurs with aging results in a decrease in alveolar surface area and a decrease in gas exchange.