How do parasympathetic neural signals affect the working of the heart? [2014]
Reduce both heart rate and cardiac output.
Heart rate is increased without affecting the cardiac output.
Both heart rate and cardiac output increase.
Heart rate decreases but cardiac output increases.
(1)
A special neural centre in medulla oblongata can moderate the cardiac function through autonomic nervous system (ANS). Neural signals through the sympathetic nerves (part of ANS) can increase the rate of heart beat, the strength of ventricular contraction and thereby the cardiac output. Parasympathetic neural signals (component of ANS) decrease the rate of heart beat, speed of conduction of action potential and thereby the cardiac output.
