The sympathetic division and parasympathetic division are two parts of the autonomic nervous system, which controls involuntary bodily functions. The sympathetic division prepares the body for stressful situations, often referred to as the "fight or flight" response. It increases heart rate, dilates airways, and redirects blood flow to muscles, helping the body react quickly to threats. In contrast, the parasympathetic division promotes a state of rest and relaxation, often called the "rest and digest" response. It slows the heart rate, stimulates digestion, and conserves energy, allowing the body to recover and maintain homeostasis after stress has passed.