Final answer:
Sympathetic stimulation of bronchial smooth muscle causes bronchodilation, which widens the airways and increases airflow to the lungs.
Step-by-step explanation:
Sympathetic stimulation of bronchial smooth muscle results in bronchodilation. This effect is due to the action of the sympathetic nervous system activating receptors in the bronchial muscles that cause them to relax and the bronchial tubes to expand, allowing greater airflow into the lungs. This contrasts with the parasympathetic nervous system, which induces bronchoconstriction by causing muscular contraction, leading to a narrowing of the airways.
Asthma, as a chronic disease, includes symptoms like inflammation, bronchospasms (bronchoconstriction), and excessive mucus secretion, which the sympathetic nervous system counteracts through its bronchodilatory effect. The bronchodilator effect is critical for increasing air volume in the lungs during situations that demand more oxygen supply, such as exercise or stress. Thus, during sympathetic stimulation, the airways widen to facilitate breathing.