Lungs

The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

AIDS

AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that leaves the body vulnerable to a host of life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medication can suppress symptoms. AIDS is universally fatal, in large part due to the proliferation of opportunistic infections.

Pneumocystosis

Pneumocystosis is an infection of the lungs caused by the microorganism Pneumocystis carinii. Pneumocystosis is almost exclusively seen in individuals whose immune systems have been compromised by AIDS or chemotherapy. Pneumocystosis is usually a terminal event in AIDS patients.