Alveoli are situated next to one or more pulmonary capillaries. They deliver oxygen to the capillaries and take up carbon dioxide from them.
Bronchioles lead into alveoli, the smallest air spaces.
Includes chronic bronchitis and emphysema, some cases of asthmatic bronchitis, and other less common conditions such as cystic fibrosis. Used as drugs in treating severe asthma, the hormones can be taken orally or intravenously. Animal dander is a common allergen. In some people, it is their only trigger. Removes from the air tiny particles that can irritate sensitive respiratory systems.