What does bronchiolitis primarily affect in the lungs?

Bronchiolitis is primarily characterized by the inflammation of the small airways in the lungs, known as bronchioles. This condition is most commonly seen in infants and young children and is typically caused by viral infections, such as respiratory syncytial virus (RSV).

The bronchioles are the smallest air passages in the lungs, branching off from the larger bronchial tubes. When these airways become inflamed and narrowed due to infection, it leads to symptoms like wheezing, coughing, and difficulty breathing, which are characteristic of bronchiolitis. Recognizing this focus on the small airways is crucial for understanding the pathology and treatment of the condition, as interventions often aim to relieve the inflammation and facilitate easier airflow through these passages.

The other options involve other structures in the respiratory system, but bronchiolitis specifically impacts the bronchioles, highlighting the importance of this particular area in the pathophysiology of the disease.