What effect does the Sympathetic Nervous System have on heart rate?

The Sympathetic Nervous System plays a crucial role in the body's "fight or flight" response. When activated, it primarily prepares the body to react to stress or potential danger. One of the key physiological changes that occur during this response is an increase in heart rate. This acceleration in heart rate allows for improved blood flow and oxygen delivery to muscles, enhancing physical performance and readiness to respond to threats.

The Sympathetic Nervous System achieves this by releasing neurotransmitters such as norepinephrine, which bind to receptors on the heart to increase the force and frequency of heartbeats. As a result, during times of stress or physical activity, the heart beats faster to meet the body's heightened demands for energy and oxygen.

Understanding this function is essential for grasping how the autonomic nervous system influences bodily functions, especially in response to various stimuli.