Correct option is A
Explanation-
Option a - Bronchodilation — is the incorrect statement.
J-receptor stimulation does not cause bronchodilation. It is more likely to cause bronchoconstriction or no direct effect on bronchi. Bronchodilation occurs due to sympathetic (β2-receptor) stimulation — not through J-receptors.
Option b - Decreased heart rate - Correct
Pulmonary J (juxtacapillary) receptors, when stimulated (e.g., by pulmonary congestion or hyperinflation), activate vagal afferents. This leads to parasympathetic activation causing bradycardia (decreased heart rate).
It is a well-established reflex in response to lung receptor stimulation.
Option c - Apnoea followed by rapid breathing - Correct
J-receptor stimulation initially causes apnoea (temporary cessation of breathing). This is followed by rapid, shallow breathing (tachypnea). This respiratory pattern is typical of J-receptor response and is commonly observed in pulmonary edema or hyperinflation conditions.
Option d - Low blood pressure - Correct
J-receptor activation can lead to vasodilation through reflex parasympathetic activity. This causes a drop in blood pressure, especially in cases of acute pulmonary congestion. It is part of the systemic effects caused by activation of pulmonary sensory receptors.
Since option a is the only incorrect statement that makes it a correct answer.
