An animal suddenly notices that a predator is stalking it and preparing to attack. Physiological responses to this stress, including vasodilatation in skeletal muscles, widening of the pupils, increases in heart rate and blood pressure, and dilation of the bronchioles result from:
A) Increased activity of the sympathetic nervous system
B) Increased activity of the parasympathetic nervous system
C) Sudden discharges from the vagus nerve
D) A mixture of parasympathetic and sympathetic stimuli

Question

Quizplus · Accepted Answer

Vasoconstriction and vasodilatation of blood vessels, bronchoconstriction and bronchodilation, and changes in heart rate (bradycardia and tachycardia), are all influenced by the sympathetic component of the ANS. The parasympathetic components of the ANS alter functions such as penile erection, the digestion of foods, urinary continence, among others.

An Animal Suddenly Notices That a Predator Is Stalking It