Question

The fact that the sympathetic division effect on the smooth muscle can be either relaxation or contraction indicates that

a)in some synapses with the smooth muscle the sympathetic fibers release Ach
b)there are 2 sub-divisions of the sympathetic system
c)there is more than one receptor type
d)some sympathetic fibers synapse with parasympathetic fibers

Answer 1

The fact that the sympathetic division effect on the smooth muscle can be either relaxation or contraction indicates that there is more than one receptor type.

Step-by-step explanation:

The fact that the sympathetic division effect on the smooth muscle can be either relaxation or contraction indicates that:

a) in some synapses with the smooth muscle the sympathetic fibers release Ach.

b) there are 2 sub-divisions of the sympathetic system.

c) there is more than one receptor type.

d) some sympathetic fibers synapse with parasympathetic fibers.

The sympathetic division of the autonomic nervous system releases norepinephrine onto adrenergic receptors in some smooth muscle, causing contraction, while in other places it releases Ach onto muscarinic receptors, causing relaxation. Therefore, option c) is correct.