In the healthy lung the airsacs look like a bunch of grapes. Ventilation is the movement of air in and out of these airsacs. Each airsac is surrounded by blood vessels. Perfusion is the movement of blood through these vessels. The area where the airsacs and blood vessels meet is where the exchange of oxygen and carbon dioxide occur. Air is inhaled. The oxygen moves from the airsacs of the lung to the blood. It then travels to the cells of the body. Carbon dioxide travels from the cells of the body to the airsacs of the lung through the blood.
The term COPD is an abbreviation for Chronic Obstructive Pulmonary Disease. COPD is a general term used to describe the chronic lung disease linked with cigarette smoking. When the lungs are affected by COPD there is a relatively irreversible decrease in airflow and permanent destruction of the airsacs in the lung. Over time this creates some areas where there is a blood supply without any airsac. This is considered a ventilation-perfusion mismatch.
When airsacs of the lung are destroyed, there is less surface area for oxygen to get from the lungs into the blood and for carbon dioxide to get from the blood into the lungs to be exhaled. This can reach a point where the amount of oxygen in the blood is low. This is called hypoxemia. This can also reach a point where the amount of carbon dioxide in the blood is high. This is called hypercarbia or hypercapnia.
Copyright 1994-2018MedHelp.All rights reserved. MedHelp is a division of Vitals Consumer Services, LLC.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. MedHelp is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.