Which class breaks chemical bonds in mucus to lower viscosity?

Which class breaks chemical bonds in mucus to lower viscosity?

• A. Mucoregulator
• B. Bronchodilator
• C. Expectorant
• D. Mucolytic

Answer: (D)

Mucolytics work by breaking chemical bonds in mucus to reduce its stickiness and make it easier to clear from the airways. The mucus network is formed by mucin proteins linked together by disulfide bonds, which give mucus its thick, elastic quality. A mucolytic provides reducing sulfhydryl groups that cleave these disulfide bonds, disrupting cross-links and lowering both viscosity and elasticity. This helps patients cough up or suction out thick secretions more effectively, which is especially important in conditions with very dense mucus, like cystic fibrosis or chronic bronchitis. While other classes influence mucus in different ways—mucoregulators change how much mucus is produced, bronchodilators ease airflow by relaxing airway muscles, and expectorants primarily help mobilize mucus or stimulate coughing—none of them primarily act by breaking the chemical bonds within the mucus network.

Mucolytics work by breaking chemical bonds in mucus to reduce its stickiness and make it easier to clear from the airways. The mucus network is formed by mucin proteins linked together by disulfide bonds, which give mucus its thick, elastic quality. A mucolytic provides reducing sulfhydryl groups that cleave these disulfide bonds, disrupting cross-links and lowering both viscosity and elasticity. This helps patients cough up or suction out thick secretions more effectively, which is especially important in conditions with very dense mucus, like cystic fibrosis or chronic bronchitis. While other classes influence mucus in different ways—mucoregulators change how much mucus is produced, bronchodilators ease airflow by relaxing airway muscles, and expectorants primarily help mobilize mucus or stimulate coughing—none of them primarily act by breaking the chemical bonds within the mucus network.