ANATOMY

Detailed explanation-1: -The sympathetic nervous system (SNS) releases the hormones (catecholamines-epinephrine and norepinephrine) to accelerate the heart rate. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate.

Detailed explanation-2: -Your sympathetic nervous system is best known for its role in responding to dangerous or stressful situations. In these situations, your sympathetic nervous system activates to speed up your heart rate, deliver more blood to areas of your body that need more oxygen or other responses to help your get out of danger.

Detailed explanation-3: -eg, the sympathetic nervous system can accelerate heart rate, widen bronchial passages, decrease motility (movement) of the large intestine, constrict blood vessels, cause pupil dilation, activate goose bumps, start sweating and raise blood pressure.

Detailed explanation-4: -It is a component of the autonomic nervous system. It controls and regulates various involuntary actions in our body. It causes the heart beat to accelerate.

Detailed explanation-5: -The sympathetic nervous system ("fight or flight” system) results in an increase in heart rate and strength of heart contraction leading to a greater stroke volume.