👉 Birds' fluid, commonly referred to as air sacs, plays a crucial role in their respiratory system, enabling highly efficient gas exchange. These air-filled sacs, which extend throughout the bird's body and even into some bones, act as extensions of the lungs, creating a continuous flow of air through the respiratory tract. This unidirectional airflow ensures that oxygen-rich air moves consistently through the lungs, maximizing oxygen absorption and carbon dioxide removal. Unlike mammals with tidal breathing, birds' air sacs facilitate a constant exchange, allowing for a more efficient respiratory process that supports their high-energy lifestyles and flight capabilities.
