Human Respiratory System

Study Notes

The lungs are spongy organs responsible for exchanging oxygen and carbon dioxide through tiny air sacs called alveoli.
Oxygen and carbon dioxide are exchanged in and out of capillaries in the alveoli.
The breathing passages (nose, throat, trachea, and bronchi) are lined with mucous membranes that provide an initial defense against pathogens and irritants.
The lungs are highly vulnerable to disease and can become seriously diseased.

Pleurisy is a disease caused by inflammation of the pleura, the double membranes surrounding each lung and lining the chest cavity.
Pleurisy can occur as a complication of pneumonia or result from direct infection of the pleura.
Asthma is a disease caused by inflammation of the muscle surrounding the airways.
Asthma is characterized by wheezing or whistling sounds accompanying each breath.
Asthma can arise from chronic bronchitis, respiratory allergies, or exposure to airborne irritants over long periods.
Most cases of asthma are treated with inhalable drugs that reduce inflammation and relax the bronchiolar muscle.
Serious cases of asthma may require oral corticosteroids.