鸡皮疙瘩和鹅有关？

鸡皮疙瘩的产生说简单点，其实就是立肌的收缩活动Contraction activity

先说立毛肌，它的活动受肾上腺素adrenaline和交感神经支配sympathetic nervous system当发生恐惧、害怕等精神情绪变化时，交感神经兴奋，肾上腺素水平增高，立毛肌收缩，毛发直立，即发生所谓的毛骨耸然、起鸡皮疙瘩现象。

而竖毛肌Erector Muscle，是指在哺乳类mammals的皮肤上,在由于寒冷及其它原因引起收缩时，可使皮肤面上斜长着的毛成为直立的状态，因此也有调节体温n.thermoregulation的作用

Imagine you're watching a scary movie and a masked man suddenly appears and kills the beautiful girl, scaring the hell out of you and giving you those infamous臭名昭著 "goosebumps".

To get over恢复 the scary film that you were just watching, you decide to go for a swim in a nearby lake.The water is quite warm, but there is a strong wind blowing, and the moment you step out of the water, you feel chilly and for the second time that night, you get goosebumps.

That same night, you're listening to some old music, and it brings back some fond memories愉悦的回忆
You begin to get all nostalgic怀乡的 and emotional, and guess what! You get "goosebumps" yet again!

So, why do these three unrelated events all seem to produce the same physical reaction in the body?

What are goosebumps and why do we get them?

Goosebumps are tiny elevations of the skin at the base of the hair, causing our skin to resemble类似 the skin of poultry after the feathers have been plucked.
The physical reaction of goosebumps have been passed to humans from our animal ancestors, who once had a lot more hair on their bodies.

Goosebumps are caused when stress (cold temperature, perceived threat, intense emotions etc.) is experienced by our brain.

In these moments, the nervous system sends a message to nerve endings that trigger the arrector pili muscles立毛肌, which cause goosebumps to appear.

In animals with long hair, goosebumps help them protect against cold weather, as standing hair provides more insulation绝缘to the body.

Also, a number of animals, including cats, use goosebumps to look larger and more intimidating when they feel threatened.

In humans, goosebumps are a pretty useless feature, as we do not have much hair on our skin, but it can be a good indicator of our surroundings, whether we are too chilly, nervous, overextended过度负担, or emotionally drained!感情枯竭

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其实比起引起鸡皮疙瘩缘由，我更好奇为什么鸡皮疙瘩会翻译成goosebumps, 难道是鹅皮疙瘩？也许在每个文化中的人都习惯用自己比较熟悉的食物做比喻，西方人养鹅比较多，所以用鹅身上的疙瘩来形容。

let's call it a day!