Final answer:
The trachea and air passageways within the lungs, including the bronchi and bronchioles leading to the alveoli, are components of the lower respiratory tract. These structures facilitate the journey of air and the crucial process of gas exchange in the lungs, assisted by the diaphragm.
Step-by-step explanation:
The trachea and the air passageways within the lungs, which include the bronchi and bronchioles that eventually lead to the alveoli, are the components of the lower respiratory tract. These structures constitute the pathway for air to travel from the external environment, through the conducting zone of the respiratory system, to the respiratory zone where the critical process of gas exchange occurs. The lower respiratory tract starts below the epiglottis in the larynx or voice box, continuing through the trachea that bifurcates into the left and right bronchi, then further divides into bronchioles and culminates in the alveoli enveloped by capillary networks.
Lung tissue is mainly comprised of the alveoli, the site of gas exchange where oxygen is transferred into the bloodstream and carbon dioxide is expelled. This complex network of air passages can be visualized as an inverted tree-like shape, with the trachea serving as the trunk, bronchi as the primary branches, and bronchioles as smaller offshoots, all of which conduct air and facilitate breathing in conjunction with the respiratory muscles such as the diaphragm.