Why does an asthma patient experience reduced airflow during a bronchospasm?

💡 Explanation

During an asthma exacerbation, mast cell degranulation releases histamine and leukotrienes, triggering airway smooth muscle constriction. This bronchospasm decreases the airway diameter, therefore airflow is reduced, rather than alveolar rupture or changes in mucus viscosity which are different mechanisms.

• If an influenza vaccine elicits a weak germinal center response due to a novel viral strain, which consequence regarding antibody affinity maturation is most likely?
• A patient with a genetic defect has impaired Class II MHC protein expression on antigen-presenting cells (APCs). If exposed to a novel pathogen, which consequence is most likely?
• An individual with a known bee sting allergy experiences anaphylaxis after being stung. Which mechanism explains why localized mast cell degranulation rapidly leads to systemic vasodilation and bronchoconstriction?
• Why does the glomerular filtration rate decrease in acute kidney injury involving nephron damage?
• Why does localized atherosclerosis in arteries often lead to systemic hypertension rather than remaining a localized pressure effect?
• A patient experiencing an ischemic stroke receives tPA, but despite initial reperfusion, neurological deficits worsen. Which process is most likely contributing to this paradoxical decline?