John Encounters a Bear While Hiking

Question

John encounters a bear while hiking. His heart will respond in all of the following ways except
A) increasing preload.
B) increasing heart rate.
C) increasing contractility.
D) decreasing heart rate and contractility.
E) increasing venous return.

Accepted Answer

When encountering a bear while hiking, the body initiates the fight or flight response, which is controlled by the sympathetic nervous system. This will lead to an immediate increase in heart rate, contractility, venous return, and preload. However, as the body continues to react to the stressful situation, the parasympathetic nervous system can be activated, leading to a decrease in heart rate and contractility to help conserve energy. Thus, the only option that is not a response to the fight or flight response is D - decreasing heart rate and contractility.