Chronic Obstructive Pulmonary Disease (COPD) (cont.)
What is chronic bronchitis?
Chronic bronchitis involves inflammation and swelling of
the lining of the airways that leads to narrowing and obstruction of the
airways. The inflammation also stimulates production of mucous (sputum), which can cause further
obstruction of the airways. Obstruction of the airways, especially with mucus, increases the
likelihood of bacterial lung infections. Chronic bronchitis usually is defined
clinically as a daily cough with production of sputum for 3
months, two years in a row. For more, please read the
Bronchitis article.
What is emphysema?
There is permanent enlargement of the alveoli due to the destruction of the
walls between alveoli in emphysema. The destruction of the alveolar walls reduces
the elasticity of the lung overall. Loss of elasticity leads to the collapse of
the bronchioles, obstructing airflow out of the alveoli. Air becomes "trapped"
in the alveoli and reduces the ability of the lung to shrink during exhalation.
The reduced expansion of the lung during the next breath reduces the amount of
air that is inhaled. As a result, less air for the exchange of gasses gets into
the lungs. This trapped air also can compress adjacent less damaged
lung tissue, preventing it from functioning to its fullest capacity.
The exchange of carbon dioxide and oxygen between air and the blood in the
capillaries takes place across the thin walls of the alveoli. Destruction of the
alveolar walls decreases the number of capillaries available for gas exchange.
This adds to the decrease in the ability to exchange gases.
Usually, energy is only required for inhalation to
inflate the lungs. The stretch of the lungs and distension of the chest cavity
springs back to rest
during exhalation, a passive process that does not require energy. However, in
emphysema, inefficient breathing occurs because extra effort and energy has to
be expended to empty the lungs of air due to the collapse of the airways. This
essentially doubles the work of breathing, since now energy is required for both
inhalation and exhalation. In addition, because of the reduced capacity to
exchange gases with each breath (due to the collapse of the bronchioles and loss
of capillaries), it is necessary to breathe more frequently.
Next: What is chronic asthma? »
- albuterol, Ventolin, Proventil, AccuNeb, Vospire, ProAir - Specifies the medication albuterol (Ventolin, Proventil, AccuNeb, Vospire, ProAir) a drug used in for the treatment of asthma, emphysema, anc chronic broncitis. Albuterol relieves and prevents of airway obstruction (bronchospasm) in patients with asthma and in patients with exercise-induced asthma. Article includes descriptions, uses, drug interactions, and side effects.
- Pneumococcal Vaccination - Learn about pneumococcal vaccination (pneumonia vaccine) recommendations and side effects, and find out who should and should not be vaccinated.
- Lung Cancer - Get the facts on lung cancer treatment, diagnosis, staging, causes (smoking), types (adenocarcinoma, squamous cell), prevention, symptoms, warning signs and survival rates.
Latest Medical News
Lungs RSS