What are the tiny sacs in the lungs that facilitate gas exchange called?

The tiny sacs in the lungs that facilitate gas exchange are called alveoli. These structures are crucial for the respiratory system as they provide a large surface area for gas exchange to occur. Each alveolus is surrounded by a network of capillaries that allow oxygen from the air to enter the bloodstream while simultaneously enabling carbon dioxide to be expelled from the blood into the alveoli to be exhaled.

Alveoli maximize the efficiency of gas exchange due to their thin walls and extensive surface area, making them extremely effective at transferring oxygen and carbon dioxide. This process is vital for respiration and therefore for maintaining the body’s oxygen levels.

In contrast, bronchi are larger air passages that lead from the trachea to the lungs but do not directly facilitate gas exchange. Veins are blood vessels that carry blood towards the heart, and arterioles are small blood vessels that lead to capillaries but do not perform gas exchange themselves. Therefore, understanding the role of alveoli and their structure is essential in the context of human respiration.