What structure in the respiratory system is responsible for filtering and humidifying air before it reaches the lungs?

The trachea plays a crucial role in the respiratory system by filtering and humidifying air as it is inhaled. This structure, often referred to as the windpipe, is lined with ciliated mucous membranes that trap particles, pathogens, and debris present in the air. The cilia, small hair-like structures, work to move mucus, which captures these unwanted substances, upward toward the throat where it can be expelled or swallowed. Additionally, as air passes through the trachea, it is moistened and warmed before reaching the lungs, which helps to protect the delicate lung tissue from irritation and damage. This process is vital for maintaining respiratory health and ensuring that the air reaching the alveoli, where gas exchange occurs, is clean and appropriately conditioned for optimal function.