Expected headings
"Tracheobronchial tree"
"Conduction zone"
"Respiratory zone"
"Physiology"
"Gas is warmed and humidified as it is conducted from the oropharynx to the functional portion of the lung, where gas exchange occurs. The conduction zone is composed of the trachea, bronchi, bronchioles and terminal bronchioles. Their function is to optimise gas delivery to the functional portion of the lung. Their walls contain cilia to remove particulates from the inspired air and cartilage to prevent collapse during expiration."
"The lungs are supplied by sympathetic, parasympathetic and visceral afferent fibres from the pulmonary plexus, which itself is composed of fibres from the vagus nerve (parasympathetic and visceral afferent fibres) and fibres from the cervical and upper four sympathetic ganglia."
"The respiratory zone is an extension of the tracheobronchial tree at the level of the terminal bronchioles. It is composed of respiratory bronchioles, alveolar ducts and alveoli, and is the site of gas transfer within the lung. In any organ, the parenchyma refers to the functional tissues; thus, the strict definition of lung parenchyma includes only the alveoli, alveolar ducts, and respiratory bronchioles 8-10. Other authors may include interstitial tissues in the definition of lung parenchyma 11."