Avian respiratory system

The avian respiratory system is highly efficient, enabling birds to meet their high oxygen demands during flight. Air flows through a series of air sacs connected to the lungs, allowing for continuous and one-way airflow. This system ensures fresh air passes through the lungs with each breath, maximizing oxygen exchange. As a result, birds can sustain active movements and high energy activities. The structure involves a unique arrangement of respiratory sacs and lungs that operate in a unidirectional flow, making avian respiration one of the most efficient among vertebrates.