Inhalation of harmful particles less than 2 micrometers can compromise which type of tissue?

• A. Nasal epithelium
• B. Alveolar epithelium
• C. Bronchial epithelium
• D. Respiratory muscle tissue

Answer: (B)

Inhalation of harmful particles that are less than 2 micrometers in size primarily affects the alveolar epithelium because these tiny particles can bypass the upper airways and bronchi, reaching the lungs' air sacs, or alveoli. The alveolar epithelium is particularly vulnerable because it is the site of gas exchange; thus, any damage from inhaled toxins or pathogens can lead to significant respiratory problems, such as inflammation, impaired gas exchange, and the potential development of diseases like pneumonia or interstitial lung disease.

Particles of this size can evade the body's defense mechanisms, such as mucous secretions and ciliary actions, which are more effective in the larger airways. Once in the alveoli, these harmful substances can provoke an immune response or cause direct cellular damage, leading to further complications.

Other types of respiratory tissues, such as the nasal epithelium and bronchial epithelium, have protective mechanisms that filter out larger particles and are less likely to be compromised by particles of this size. Respiratory muscle tissue, on the other hand, comprises the muscles that facilitate breathing and is not directly impacted by inhaled particles in the same way that epithelial tissues are.