abstract blue human bronchial tree with red target sign. lungs, bronchioles, trachea. healthcare medical concept. low

human medical bronchiolar pneumonia respiratory cancer organ bronchiole trachea bronchi alveoli lung tract emphysema anatomy bronchioles alveolar bronchial tube chronic obstructive disease bronchitis asthma tuberculosis cystic fibrosis flu virus coronavirus tree sign symbol point target goal aim focus protect save antitrypsin deficiency bronchodilator mucolytic osmotic agent inhaled antibiotic antiviral therapy