Encounter emergency for example, can direct exciting adrenalin mixes sympathetic system go armour adrenalin, in its at the same time nerve ending proper motion secretes similar substance, bring the body into play to make response quickly.

• 例如碰到紧急情况，交感神经系统会直接刺激肾上腺素和去甲肾上腺素，同时在其神经末梢自行分泌类似的物质，调动身体迅速作出反应。