时间:2019-02-24 作者:英语课 分类:英语听力文摘 English Digest


英语课

  Hey! and then…Ouch!

伤害性刺激作用于末梢神经引起神经兴奋电活动,沿着脊髓传人神经纤维中的细纤维(A和c纤维)传人脊髓,进而引起痛觉。痛觉是由于痛觉感受器受刺激而诱发的,其他感受器受到刺激产生相应的感觉,并非痛觉。人体内痛觉的传导依赖于机体受刺激侧对侧脊髓前外侧1/4象限内上行神经纤维构成的传导束的功能完整性。先天Jf生痛觉缺如的起因与痛觉相关的脊髓传人神经纤维的缺乏有关。参与痛觉产生的高级神经中枢为丘脑和大脑皮质,这些部位的损伤可以引起痛觉减弱。

'Hey! and then…Ouch!' on this Moment of Science.


  One thing we don’t want anyone to do is poke 1 themselves with a sharp object after reading this Moment of Science. But the next time you accidentally get poked 2 you might notice something interesting.

Say you reach into a pile of clothes where a needle is sticking up. If you are able to reflect for a moment as you are sucking your fingertip, you may realize that you have had two separate sensations.

The first of these is what we might think of as the “hey!” sensation. It conveys the information that something startling has happened to your finger, and that thing is unpleasant. A moment after that comes a deeper-down feeling of pain. This latter sensation might be called the “ouch!” It’s not startling so much as just plain bad.

What’s going on here?

In fact, there are several different kinds of fibers 3 that send pain information to your brain. These are called “nociceptors,” and they respond not only to pins but to heat, cold, chemical changes, and other dangers. These receptors send their information through two different kinds of fibers: the large, fast “A” fibers, and the smaller, slower “C” fibers.

Because they are naturally coated with a conductive substance, “A” fibers transmit messages at about 330 feet per second, whereas “C” fibers can only handle about six-and-one-half feet per second.

The delay some people can distinguish between “Hey!” and “Ouch!” is thought to be due to this time lag. It also makes sense that the faster “A” fibers would be the ones whose job it is to get you to pull your finger away right now.



n.刺,戳,袋;vt.拨开,刺,戳;vi.戳,刺,捅,搜索,伸出,行动散慢
  • We never thought she would poke her nose into this.想不到她会插上一手。
  • Don't poke fun at me.别拿我凑趣儿。
v.伸出( poke的过去式和过去分词 );戳出;拨弄;与(某人)性交
  • She poked him in the ribs with her elbow. 她用胳膊肘顶他的肋部。
  • His elbow poked out through his torn shirt sleeve. 他的胳膊从衬衫的破袖子中露了出来。 来自《简明英汉词典》
光纤( fiber的名词复数 ); (织物的)质地; 纤维,纤维物质
  • Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上,以硫酸钠为凝固剂,对胶原-PVA共混溶液进行湿法纺丝,制备了胶原-PVA复合纤维。
  • Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。
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abnormal plasmocyte
air shroud
alonzo
Anatomia chirurgica
anthracite pig iron
antinativist
auctioning
Basciano
Belleterre
Birchite, Birchist
Buckland R.
cerol colors
chak-chak
coal-dust disease
commune integumentum
covariate
curved shape
cycloadducts
darlie
Dinangourou
disquarter
Distributed-repetition
dual boot
earn one's keep
eaten one's words
effective interest rate
endovascular
Enga Prov.
Eskimau
ethyl phosphate
factualize
fibroma lipoidicum
film distortion
fire engines
follow into
fundamental lattice vector
glucoseptanosides
goldminings
heedling
heterarchical control
high pelvic position
histrion
in-line tellurics
indecorousness
junge law
knife edge of balance
Kray twins
kryptonated solid
letterfracks
Libānggaon
litvak
locating apparatus
Lopez Point
Mahrati
make it one's business to do
mammary tumor virus (mtv)
maximum hygroscopicits
mean distance
moist-air pump
mycogenic
New Tredegar
nine-months
Nugent
over-deliver
paper house
paper-mill
parallel of altitude
perfemane rock (c.i.p.w)
petrolatums
phyllosticta lycopersici peck
polariscop
polytropic compression
potash albite
QSG
quiners
ram induction
salt-bath chromizing
saprovitrinite
sea of gate
segment property
segment relative address
silicone rubber sealant
stigmata of degeneracy
sub-paragraphs
tetrazone
Teutonicizes
think no small bear of
thinnish
toolhouse
toothlessness
trilinear line coordinates
twank
udalmen
umaa
undersalting
ungrateful person
universitt
Vialpha
vocal muscles
vulval tuberculosis
Waldershof
warlings