The lung has two main bronchi, from which intricate bronchial branches arise, which process oxygen from the air and transmit it into the circulatory system. Blocked airways can cause severe health complications. The most frequent diseases of the respiratory system are: acute bronchitis, chronic bronchitis, asthma and pneumonia. This infographic from the Ábaco collection is integrated into the Diseases series, which includes the titles: Allergies, Bone Degenerations and Diabetes.