Cells in the human eye send nerve impulses to the brain that cause the pupil to constrict. This is an example of a reaction to what kind of stimuli?.

The answer would be true.

Unlike  ct scans, which use x-rays,  mri scans  use powerful magnetic fields and radio frequency pulses to produce detailed pictures of organs, soft tissues, bone and other internal body structures.  differences between  normal and abnormal tissue is often clearer on an  mri  image than a  ct.you can see more with a mri scan. for example on an mri you can see internal bleeding.