Question

A client with a 30 year history cigarette smoking has developed emphysema which pathophysiology mechanism results in the greatest interference with normal gas exchange for this client.

Answer 1

EMPHYSEMA : abnormal permanent enlargement of the airspace distal to thee terminal bronchiole , accompanied by destruction of their walls and without obvious fibrosis.

PATHOPHYSIOLOGY OF EMPHYSEMA

Normally our alveoli of lungs and bronchiole contain elastic fibres . alveoli also contains epithelia , surfactant cells , alveolar macrophages , and. Antiprotease which maintains balance with protease , and protect the alveoli from damage by Protease . If there is any imbalance between protease and antiprotease results in emphysema .

1) when a person do heavy smokes , the smoke contains REACTIVE OXYGEN SPECIES or oxidative toxin ( free radicals ) , and these enters in lungs alveoli via bronchiole , starts inflammatory response in body . When these toxins comes in contact with macrophages in alveoli , macrophages starts secreting the .Inflammatory mediators , inflammatory cytokines like IL-1, IL-6,IL-8 ( major ) ANDINF - alpha .these chemicals enhance the immune response , specially INF- alpha and IL-1 .Recruit the neutrophils in area ,process known as chemotaxis , . Now the neutrophils will secret the .protease enzyme in area and cause leads the destruction of elastase fibre . Along with this macrophages also secrets the metalloprotease which other type of protease .

Protease is also known elastase which destroy elastic fibres , specially metalloprotease damages tissue.

If person keeps smoking , more oxidative toxins leads to more and more recruitment of neutrophils . And also macrophages activity will continue . But now T- lymphocytes will also comes and damage the tissue by T cell mediated apoptosis and after sometime college deposition occure and fibrosis

So the alveolar tissue and septa of alveoli has been damage , which results in EMPHYSEMA.

C) And structural changes are

-Hyperinflation of alveoli

-destruction of alveolar and alveolar capillary wall.

-small airway narrow

-Lungs elasticity decreases which result in air trapping in alveoli because recoilling capacity of alveoli to expelle the air out of lungs is reduced and narrowing of airways Does not provide adequate space to air for removal.

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