Question

1. Explain the effects of the ANS on the heart. Include specific mechanisms beginning with the receptor type involved. You don’t have to list every step in the signaling cascades, just summarize the beginning and end and go into detail regarding the end result cellular effects and how they change HR and contraction force.

Answer 1

The ANS is responsible for controlling and regulating wide range of physiological functions which includes the contraction of heart as well as heart rate. Within the carotid sinus and aortic arch of the heart the baroreceptors are located, and they can detect the change in the stretch. This helps in detecting any change in the arterial pressure. When there is an increase in the arterial pressure, there is reduction in the heart rate with the activation of the parasympathetic pathway and hence it helps in vasodilation of blood vessels. When the baroreceptors detects a decrease in arterial pressure, it activates the sympathetic pathway and hence it helps in increasing heart rate and increase heart contraction. This tends to increase the vasoconstriction of vessels and hence increases arterial pressure.