Question

When under stimulation from the sympathetic nervous system (SNS), the broncHIOles ___ (dilate or constrict) and when stimulated by the parasympathetic nervous system (PNS) the broncHIOles ___ (dilate or constrict).

1) Dilate, constrict
2) Constrict, dilate
3) Dilate, dilate
4) Constrict, constrict

Answer 1

When the sympathetic nervous system is stimulated, the bronchioles 1) dilate. When the parasympathetic nervous system is stimulated, the bronchioles constrict. The correct answer is 1) Dilate, constrict

Step-by-step explanation:

When under stimulation from the sympathetic nervous system (SNS), the bronchioles dilate. The sympathetic system activates the release of epinephrine and norepinephrine, which bind to receptors on the smooth muscle of the bronchioles, causing relaxation and dilation.

On the other hand, when stimulated by the parasympathetic nervous system (PNS), the bronchioles constrict. The parasympathetic system releases acetylcholine, which binds to receptors on the smooth muscle of the bronchioles, causing contraction and constriction. Therefore the correct answer is 1) Dilate, constrict