Obstructive pulmonary diseases correct answers those that cause obstruction of the airways,
usually through a combination of bronchoconstriction and inflammation. These include
bronchitis (chronic or acute) and emphysema
chronic obstructive pulmonary disease (COPD) correct answers progressive disorder that slowly
alters the structures of the respiratory system over time, irreversibly affecting lung function.
The disease is one of periodic exacerbations, often related to respiratory infection, with increased
symptoms of dyspnea and sputum (mucus or mucopurulent matter expectorated from the lungs)
production.
Unlike acute processes in which lung tissues recover, airways and lung parenchyma do not return
to normal following an exacerbation; instead, they demonstrate progressive destructive changes.
COPD is not curable, but it can be managed (and sometimes prevented) with appropriate medical
interventions and lifestyle choices.
COPD typically includes components of both chronic bronchitis and emphysema, two distinctly
different processes.
Small airways disease, narrowing of small bronchioles, is also part of the COPD complex.
Through different mechanisms, these processes cause airways to narrow, resistance to airflow to
increase, and expiration to become slow or difficult.
The result is a mismatch between alveolar ventilation and blood flow or perfusion, leading to
impaired gas exchange.
,lung parenchyma correct answers portion of the lung involved in gas transfer—the alveoli,
alveolar ducts and respiratory bronchioles
Emphysema correct answers a condition in which the air sacs of the lungs are damaged and
enlarged, causing breathlessness.
Characterized by destruction of the walls of the alveoli, with resulting enlargement of abnormal
air spaces
Deficiency of α1-antitrypsin, an enzyme that normally inhibits the activity of proteolytic
enzymes and tissue destruction in the lungs, contributes to the development of emphysema in
some individuals, especially when combined with exposure to cigarette smoke.
Inflammatory cells that collect in distal airway tissues appear to lead to destruction of elastic
fibers in the respiratory bronchioles and alveolar ducts. Alveolar wall destruction causes alveoli
and air spaces to enlarge, with loss of corresponding portions of the pulmonary capillary bed. As
a result, the surface area for alveolar-capillary diffusion is reduced, affecting gas exchange.
Elastic recoil is lost, reducing the volume of air that is passively expired. The loss of support
tissue also affects airways, increasing the risk of expiratory collapse and further air trapping.
Either respiratory bronchioles or alveoli may be the primary tissue involved anatomically.
As in chronic bronchitis, cigarette smoking is strongly implicated as a causative factor in most
cases of emphysema.
Asthma often exists as a comorbid disease in the patient with COPD. Patients who have lived
with moderate to severe persistent asthma for most of their lives may develop COPD as a result
of airway remodeling and damage to alveoli over time
chronic bronchitis correct answers a condition in which the bronchi in the lungs are constantly
swollen and clogged with mucus
, disorder of excessive bronchial mucus secretion
It is characterized by a productive cough lasting 3 or more months in 2 consecutive years
Cigarette smoke is the major factor implicated in the development of chronic bronchitis.
Inhaled irritants lead to a chronic inflammatory process with vasodilation, congestion, and edema
of the bronchial mucosa.
Goblet cells increase in size and number, and mucous glands enlarge. Thick, tenacious mucus is
produced in increased amounts.
Changes in bronchial squamous cells impair the ability to clear mucus
Narrowed airways and excess secretions obstruct airflow; expiration is affected first, then
inspiration.
Because ciliary function is impaired, normal defense mechanisms are unable to clear the mucus
and any inhaled pathogens.
Recurrent infection is common in chronic bronchitis.
COPD pathophysiology correct answers results from repeated exposure to respiratory irritants
that begin to damage the structures of the respiratory system.
Damage to the large and small airway passages causes increased mucus production, causing
arrest in cilia action.
Excessive amounts of fluid accumulate with the lung mucosal cells, causing edema.