BIOL 221 Lecture Notes - Lecture 7: Cystic Fibrosis, Respiratory Acidosis, Bronchitis
Document Summary
Single gene defect of a cl- transport protein. Overproduction of thick mucus reduces usable diameter of airways. Cystic fibrosis arises from a single gene defect of a chloride transporter. As a result viscous mucus accumulates in the lower airways and breathing is very labored. Gene therapy is ineffective because researchers can"t get gene into stem cells. Chronic irritation or infection of the bronchi. Chronic bronchitis is caused by chronic irritation or infection of the bronchi. As a result the wall of the bronchus thickens narrowing the airway. Chronic bronchitis is often associated with smoking. Sometimes these patients are referred to as blue bloaters because there is decreased oxygenation of the blood. Because the alveoli are not properly ventilated, carbon dioxide accumulates. The elevated carbon dioxide (hypercapnia) causes respiratory acidosis and constriction of the pulmonary arterioles; this can lead to right sided heart failure. Hypoxemia also results from the decreased ventilation; this may cause secondary polycythemia (erythrocytosis) due to renal hypoxia.