Final answer:
The missing respiratory system organ is the trachea, which is essential for conducting air to the lungs. The trachea connects with other critical respiratory organs to perform gas exchange, aided by the cardiovascular system.
Step-by-step explanation:
The missing organ from the list that is part of the respiratory system is the trachea. The trachea is an essential component of the respiratory tract that connects the larynx to the bronchi, allowing air to pass through during the process of breathing. In context, the lungs, bronchioles, and alveoli are parts of the respiratory system that work together to facilitate gas exchange.
Gas exchange is the primary function of the respiratory system, which is complemented by the cardiovascular system. The respiratory system brings in oxygen and expels carbon dioxide, while the cardiovascular system transports these gases in the blood between the lungs and body tissues. The correct sequence of the respiratory organs through which air passes is: nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.
The organ that is part of both the digestive and respiratory systems is the pharynx. Lastly, the statement that bronchioles branch into bronchi is false; it is the other way around, as bronchi branch into bronchioles.