Why does bronchoconstriction occur during an asthma attack despite normal atmospheric oxygen?

💡 Explanation

During an asthma attack, mast cells release histamine, which triggers smooth muscle contraction in the bronchioles, reducing airflow and causing bronchoconstriction. This occurs because histamine increases intracellular calcium, leading to constriction, therefore airways narrow despite sufficient oxygen, rather than impaired gas exchange or hemoglobin function.

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