Question

Circle all correct answers

.1. Circle the true statements about the pulmonary pressures graph.

a. Intrapleural pressure is normally supra-atmospheric.

b. Transpulmonary pressure increases as inspiration proceeds.

c. Intra-alveolar pressure is lowest at the end of inspiration.

d. Alveolar pressure is positive in the end of exhalation.

2. (a) Excess fluid in the alveoli is known as __________

(b) What is the effect of this fluid on surface tension? Use Law of LaPlace to explain

Answer 1

Ans 1) The correct statements are

Transpulmonary pressure increases as inspiration proceeds.

Intra-alveolar pressure is lowest at the end of inspiration.

Alveolar pressure is positive in the end of exhalation.

During the inspiration process, there is contraction of the diaphragm and intercostals muscles leading to increase in the volume of the thoracic cavity and this turns the intrapleural pressure to become negative. As the intrapleural pressure turns negative, it increases the transpulmonary pressure causing the expansion of the lungs. Also, during the inspiration, the increased alveoli volume leads to lung expansion and decrease in the intra alveolar pressure. The alveolar pressure increases with the increase in the rate of exhalation.

Ans 2) a) Pulmonary Edema –

This is a condition where the alveoli is filled with excess fluid that is caused due to the leakage out of the blood vessels.