Question

How do bronchioles affect air flow to the alveoli?

Answer 1

Hint: The bronchi branch into bronchioles having a very narrow duct at the end of each bronchiole which leads to a cluster of microscopic bubble-like structures, called alveoli. In Latin, the word "alveolus" derives from the expression "little cavity".

Complete answer:
The alveoli are where the lungs and blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Inhaled oxygen flows from the air into the alveoli and into the blood, which passes through the tissues of the body. The exchange of gas in our lungs occurs rapidly and continuously. Alveoli are thin sacs at the end of bronchioles, but they are so compact and abundant that they increase their surface area to volume ratio.
This ratio is highly important to the life of every organism. Another significant fact is that airway resistance is inversely proportional to lung volumes because when they inflate, the airways stretch a little, so that during exhalation, the airways in a fully expanded lung would have lower resistance than a lung.

Therefore, collectively, narrower airways such as bronchioles and alveolar ducts both have much greater flow resistance than larger airways such as the trachea. The splitting of the airways, however, ensures that even more of the smaller airways operate in tandem, decreasing the maximum air flow resistance.

Note: Lecithins have the properties of emulsification and lubricant, and are a surfactant. They can be entirely metabolized by humans (see inositol), but they are well absorbed by humans and non-toxic when ingested; it is only possible to excrete certain other emulsifiers through the kidneys.