PATHOLOGY

Detailed explanation-1: -Sympathetic stimulation increases heart rate and myocardial contractility. During exercise, emotional excitement, or under various pathological conditions (e.g., heart failure)[5], the sympathetic nervous system is activated.

Detailed explanation-2: -In the heart (beta-1, beta-2), sympathetic activation causes an increased heart rate, the force of contraction, and rate of conduction, allowing for increased cardiac output to supply the body with oxygenated blood.

Detailed explanation-3: -The sympathetic nervous system prepares the body for the “fight or flight” response during any potential danger. On the other hand, the parasympathetic nervous system inhibits the body from overworking and restores the body to a calm and composed state.

Detailed explanation-4: -Heart rate is controlled by the activity of the autonomic nervous system: the sympathetic and parasympathetic nervous systems increase and suppress heart rate, respectively. To evaluate the activity of the autonomic nervous system, it is possible to determine heart rate variability using electrocardiography (ECG).