Answer
Fig. 15.9:1
In a frightened person, the pupils dilate
Work Step by Step
This is due to a rush of catecholamine neurotransmitters from the sympathetic nervous system ( of the ANS), and the adrenal medulla. In the fight or flight response to fear, threat, or anxiety, the sympathetic nerves from the superior cervical ganglion release release adrenergic neurotransmitters that stimulate the dilator muscles of the iris (pupillae dilators) to contract; the effect is, a greater area of the pupils become exposed (dilation).