Pulmonary airways

FIGURE 5.16 Depiedon of eepresentaiive airway cros seaion at various points (trachea, bronchi, and pulmonary airway) along the respiratory tract showing common cell types. Note how mucus gei is generally presumed to form sheets in the more proximal airways. The pulmonary airway depiction includes both a section of respiratory bronchi and an alveolus. 

Mean airstream velocity diminishes as inspiratory flow moves toward the lung parenchyma because of the rapid increase in total cross-sectional area. The largest increases in area occur in the distal bronchioles and pulmonary airways, causing u to approach zero because... 

Pulmonary airways Portion of respiratory tract (alveoli, respiratory bron-... 

Schreck, R. M.. and L. F. Mockros. Fluid Dynamics in the Upper Pulmonary Airways. American Institute of Aeronautics and Astronautics Paper No. 70-788, Presented at AIAA 3rd Fluid and Plasma Dynamics Conference. Los Angeles. California, June 29-July 1, 1970. 

Total Respiratory Resistance (/ i) - With appropriate attention to technical problems, resistance can be measured at various pressure perturbation frequencies of 3, 6, 9, and 12 Hz. Unfortunately, this measurement is affected by changes in upper-airway configuration, which may complicate the detection of changes in pulmonary airways per se. 

T. Toyama, and K. Nakamura, Synergistic response of hydrogen peroxide aerosols and sulphur dioxide to pulmonary airway resistance. Indust. Health 2 34-45, 1964. 

Bronchoalveolar lavage fluid (BALF) is presently the most common way of sampling components of the epithelial lining fluid and provides the most accurate reflection of pulmonary airway protein composition. Proteomic studies of BALF have already been published and have contributed to a better knowledge of the lung structure at the molecular level and the study of lung disorders at the clinical level [23]. 

The minimum amount of formaldehyde that can be detected by odor varies considerably between individuals and ranges from 0.1 to 1.0 ppm (0.12-1.2 mg/m ), close to the concentration at which minimal irritant effects are felt in the eyes and in the pulmonary airways (3). Thus, the fundamental toxicity of formaldehyde lies in primary irritation to the eyes, nose, and throat when the subject is exposed to concentrations in the range of 1-5 ppm. Concentrations above 2-5 ppm cause irritation of the pharynx, lungs, and eyes, and some erythema of vaporized areas of the skin, such as the face and neck. Acute exposure to concentrations of formaldehyde of the order of three times the maximum threshold of detection of the... 

Corticosteroids have also been examined for their effects on CBF. Interestingly, whilst corticosteroids exert effects that are ultimately protective and regenerative in the injured airway mucosa, there is evidence from studies in nasal epithelia that they actually reduce CBF (Stafenger, 1987). Whether this occurs in the pulmonary airways, and if so its potential significance, is not known. 

The mucous lining the pulmonary airways clears the deposited particles toward the throat. 

The respiratory tract is divided into regions the nasopharyngeal airway (upper respiratory tract) and the tracheobronchial and pulmonary airways (lower respiratory tract). The anterior one-third of the nasal cavity viewed in cross-section reveals a central septum dividing the two cavities. This region, including the proximal portion of the inferior and middle turbinates, is non-ciliated (Figure 13.1). The meatuses are spaces formed by the folds of the two inferior and middle turbinates. In the posterior two-thirds of the nasal cavity, clearance of deposited par-... 

The bronchial arteries supply the trachea, pulmonary airways (both intra- and extrapulmonary), regional lymph nodes, (visceral) pleura, esophagus, and vasa vasorum of aorta and pulmonary artery and vein. 

Fetita Cl, Preteux F, Beigelman-Aubry C, Grenier P (2004) Pulmonary airways 3-D reconstruction from multi-de-tector-row CT and clinical investigation. IEEE Trans Med Imaging 23 1353-1364... 

A. L. Hazel and M. Hell, Surface-tension-induced buckling of liquid-lined elastic tubes a model for pulmonary airway closure, Proc. R. Soc. Land A, 461,1847 [2005). 

Surfactant Transport and Fluid-Structure Interactions during Pulmonary Airway Reopening... 

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