the bronchules carry oxygen.
Bronchioles are the small air passages in the lungs that branch off from the bronchi and lead to the alveoli, where gas exchange occurs. Their primary function is to regulate airflow to the alveoli by constricting or dilating in response to various stimuli, thereby controlling the amount of air that reaches the lungs' exchange surfaces. Additionally, bronchioles are involved in warming and humidifying the air before it reaches the alveoli.
The smallest functional unit of respiratory system is alveoli. Gaseous exchange takes place here. * The alveoli are attached to bronchules. * bronchules to bronchus. * bronchus to trachea the windpipe.