Which term means 'Very small air cell of the lungs'?

Which term means 'Very small air cell of the lungs'?

• A. Alveoli
• B. Molecule
• C. Lymph
• D. Permeability

Answer: (A)

The essential term for the tiny air-filled units in the lungs is alveoli. These are the very small air sacs at the ends of the airways where gas exchange occurs, with each alveolus having a very thin wall to allow oxygen to pass into blood and carbon dioxide to leave. The singular form is alveolus, while alveoli is the plural, which is why this option fits the description of a very small air cell of the lungs. The other terms don’t describe lung air spaces: a molecule is far smaller than a cell; lymph is fluid from the lymphatic system; and permeability refers to how easily substances cross membranes, not a lung structure.

The essential term for the tiny air-filled units in the lungs is alveoli. These are the very small air sacs at the ends of the airways where gas exchange occurs, with each alveolus having a very thin wall to allow oxygen to pass into blood and carbon dioxide to leave. The singular form is alveolus, while alveoli is the plural, which is why this option fits the description of a very small air cell of the lungs. The other terms don’t describe lung air spaces: a molecule is far smaller than a cell; lymph is fluid from the lymphatic system; and permeability refers to how easily substances cross membranes, not a lung structure.