A person is confronted by a dangerous dog. His heart begins to race and beat strongly, his pupils dilate, and his hairs stand up. These signs are the result of
A) sympathetic activation.
B) increased levels of epinephrine in the blood.
C) increased activity of autonomic centers in the hypothalamus.
D) all of the above
E) none of the above

Question

Quizplus · Accepted Answer

All three options - sympathetic activation, increased levels of epinephrine in the blood, and increased activity of autonomic centers in the hypothalamus - are involved in the fight-or-flight response that is triggered when a person is confronted by a dangerous situation like a threatening dog. The sympathetic nervous system is activated, leading to an increase in heart rate, dilation of pupils, and piloerection (hair standing up). This is accompanied by the release of epinephrine (also known as adrenaline) from the adrenal glands, which further enhances the fight-or-flight response. The hypothalamus also plays a key role in coordinating these physiological responses.

A Person Is Confronted by a Dangerous Dog