These structures are part of a reflex arc:
Which set of numbers is the proper sequence of the pathway of impulses?
A)4,3,2,1,5
B)4,1,3,2,5
C)1,4,3,5,2
D)1,4,2,5,3

Question

These structures are part of a reflex arc: 
Which set of numbers is the proper sequence of the pathway of impulses?
A)4,3,2,1,5 
B)4,1,3,2,5 
C)1,4,3,5,2 
D)1,4,2,5,3

Quizplus · Accepted Answer

The proper sequence of the pathway of impulses in a reflex arc is as follows:
1. Stimulus is detected by a receptor (in this case, structure 4)
2. Impulses travel along a sensory neuron (structure 1) to the spinal cord
3. Impulses are processed in the spinal cord (structure 3)
4. Impulses travel along a motor neuron (structure 2) to an effector (structure 5)
5. Effector (structure 5) responds to the impulses and carries out the reflex
Therefore, the proper sequence is 4,1,3,2,5, which corresponds to choice B.

These Structures Are Part of a Reflex Arc