Question

Which of the following are characteristics of large lung volumes?

1) Flat diaphragms
2) Increased anteroposterior diameter
3) Loss of vascular markings
4) None of the above

Answer 1

Characteristics of large lung volumes include a flat diaphragm and an increased anteroposterior diameter, which are indicative of the changes that occur during deep inhalation or conditions causing hyperinflation of the lungs, such as emphysema.

Step-by-step explanation:

The characteristics of large lung volumes include a flat diaphragm and an increased anteroposterior diameter among other physiological changes. When lungs are at a large volume, such as during a deep inhalation, the diaphragm contracts and flattens out, increasing the volume of the thoracic cavity and thus the lungs. This action causes the vertical dimension of the thoracic cavity to increase. An increased anteroposterior diameter is often seen in conditions like emphysema where the lungs are overinflated, leading to a barrel-shaped chest. Loss of vascular markings may suggest pathology but is not a characteristic of large lung volume per se; therefore, options 1 and 2 are characteristics of large lung volumes.

Lung volumes and their changes are important for understanding respiratory physiology. When talking about large lung volumes, it is important to consider gas exchange in the alveoli, the role of the diaphragm and intercostal muscles, and how Boyle's Law applies to respiration.