Emphysema: Cellular and Molecular Physiology Essay

Introduction

• Emphysema is characterized by abnormal overinflation of alveoli.
• Leads to the collapse of alveoli walls.
• Results in air trapping which leads to breathing difficulties.
• Caused by prolonged exposure to irritants.

Anatomy and Physiology

• Respiratory system is divided into lower and upper airways.
• Thoracic cavity is separated from abdominal cavity by the diaphragm.
• The diaphragm contracts to enlarge the thoracic cavity during inhalation.
• Capillaries surround the alveoli to enable gaseous exchange.
• Damaged alveoli trap air and impair gaseous exchange.
• Trapped air makes lung stiff leading to shortness of breath.
• Rupture of the alveoli walls creates larger air spaces, decreasing lung capacity.

Pathology

• Alveoli damage reduces the ventilatory unit’s surface area.
• Emphysema disrupts gaseous exchange leading to hypercapnia and hypoxia.
• Affected part of the acinus determines emphysema subtype.
• The condition is subdivided into panacinar, centriacinar, and paraseptal.
• Exposure to toxic smoke forms inflammatory cells.
• Inflammatory cells cytokines that enhance emphysema development.
• Neutrophils and macrophages produce proteinases that damage parenchymal tissue.
• Imbalances in elastase increase the vulnerability of lung destruction.

Genetics

• Emphysema is inherited through an autosomal codominant pattern.
• Some versions of SERPINA1 gene production lower levels of AAT.
• AAT is an anti-proteinase neutralizes proteinase protecting the lung.
• Lower levels of AAT results in deficit, resulting in emphysema.

Epidemiology

• Reported incidence of the disease amounted to 250 million cases in 2016.
• Emphysema contains a prevalence of 10.1% in 2019.
• Largely contributes to the worldwide mortality rate with 3.23 million fatalities in 2019.
• Increased cases are enhanced by smoking and environmental pollution.

Drugs

Bronchodilators:

• Reduces pressure on airways muscles improving breathing.
• Most of bronchodilators are administered using inhalers.

Antibiotics:

• Used to prevent exacerbation by treating viral or bacterial lung infections.

Surgical Treatment

• Lung Volume Reduction Surgery (LVRS).
• Removes 30% of infected lung tissues to help enhance breathing performance.
• Bullectomy.
• Remove large bullae from the lungs that impair breathing.

Conclusion

• Respiratory system contains alveoli in the upper airway which when damaged impairs gaseous exchange.
• Damage of the alveoli walls causes permanent dilation.
• Contact with irritants forms inflammatory cells that enhance emphysema development.
• COPD conditions contribute significantly to worldwide mortality rates.
• Can be caused with a genetic deficiency of AAT.
• Emphysema contains drug treatments like bronchodilators and antibiotics and surgeries such as LVRS and bullectomy.

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