Question

question 15 1 pts which statement is not true of the alveoli of the lungs? diffusion of gases takes place across only six layers of cells. tissue fluid lining the alveoli permits the diffusion of gases. surfactant permits the inflation of alveoli by decreasing their internal surface tension. they are surrounded by pulmonary capillaries.

Explanation:

1. For the first part about oxygen - rich blood flow: Oxygen - rich blood returns from the lungs via the pulmonary veins (not arteries) to the left atrium, then to the left ventricle and out to the systemic circuit. The incorrect statements in the initial text are about the vessels (pulmonary arteries instead of veins) and the atrium (right atrium instead of left atrium). The correct path is via the left atrium and ventricle before leaving on the systemic circuit.
2. For the alveoli question: Gas diffusion in the lungs occurs across only two layers of cells (the alveolar epithelium and the capillary endothelium), not six. Tissue fluid lining the alveoli does permit gas diffusion, surfactant decreases alveolar surface tension to allow inflation, and alveoli are surrounded by pulmonary capillaries.

Answer:

For the oxygen - rich blood flow part: Oxygen - rich blood flows through the heart via the left atrium and ventricle before leaving on the systemic circuit.
For Question 15: Diffusion of gases takes place across only six layers of cells.