The ANS has two divisions:
Sympathetic: Emergency system, typically activated in face of a threat
(e.g., fight or flight)
Parasympathetic: Vegetative functions (e.g., digestion), ‘business as normal’
The two systems often act in opposition (e.g., heart rate) but can act in concert (e.g., sexual reflexes)ANS
有两个部门：
同情： 紧急系统，通常在面临威胁时激活（例如，战斗或逃跑）
副交感神经：植物功能（例如消化），“一切正常” 这两个系统经常对立（例如，心率），但可以协同作用（例如，性反射）