Bronchioles function

Lung Bronchiolitis obliterans diagnosed with lung biopsy Bronchiolitis obliterans diagnosed with pulmonary function tests and radiology0 Bronchiolitis obliterans organizing pneumonia... 

It is seen that the diameters of bronchioles (averaged over generations 11 - 15) vary little with age. The increase in bronchial size is greater, but still less than might be expected if airways are simply scaled for overall body dimensions (illustrated by the dashed curves in Figure 9, which are functions of body weight W). Since bronchiolar diameter does not change much with age it is likely that the thickness of bronchiolar epithelium is also relatively constant. However, in the case of the bronchi, it is reasonable to assume that epithelial thickness is proportional to bronchial diameter. Thus, it is necessary to use age dependent conversion factors between the surface density of alpha-decays and dose to cells. 

Two cases of accidental thionyl chloride exposure resulting in lung injury that varied from relatively mild and reversible interstitial lung disease to a severe form of bronchiolitis obliterans have recently been reported. In the first case a 30-year-old worker was exposed when a thionyl chloride tank burst in an open space. The worker was asymptomatic until dyspnea gradually developed 2 weeks after his exposure. The patient was mildly dyspneic with 22 respirations per minute, and lung function... 

When nonselective beta blockers are used, some antagonism of beta-2 receptors also occurs.2,31 The antagonism of beta-2 receptors on bronchiole smooth muscle often leads to some degree of bronchoconstric-tion and an increase in airway resistance. Although this event is usually not a problem in individuals with normal pulmonary function, patients with respiratory problems such as asthma, bronchitis, and emphysema may be adversely affected by nonselective beta antagonists. In these patients, one of the beta-1-selective drugs should be administered. 

Functional smooth muscle by 8-10 weeks, to respiratory bronchioles by 26 weeks... 

Metaproterenol [met a proe TER a nole], although chemically similar to isoproterenol, is not a catecholamine and is resistant to methyla-tion by COMT. It can be administered orally or by inhalation. The drug acts primarily at p2 receptors, producing little effect on the heart. Metaproterenol produces dilation of the bronchioles and improves airway function. The drug is useful as a bronchodilator in the treatment of asthma and to reverse bronchospasm (Figure 6.13). 

The commonest form of lung damage is an interstitial alveolitis, although pneumonitis and bronchiolitis obhter-ans have also been reported, as have sohtary localized fibrotic lesions, non-cardiac pulmonary edema, pleural effusions, acute respiratory failure, acute pleuritic chest pain, and adult respiratory distress syndrome (SEDA-17, 220) (SEDA-18, 201) (66-68). Amiodarone has also been reported to cause impairment of lung function, even in patients who do not develop pneumonitis (69), and preexisting impairment of lung function may constitute a contraindication to amiodarone. 

Padley SP, Adler BD, Hansell DM, Muller NL. Bronchiolitis obliterans high resolution CT findings and correlation with pulmonary function tests. Clin Radiol 1993 47(4) 236 0. 

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