The Neuron and Neural Firing · 神经元与神经冲动
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| all-or-nothing principle/ɔːl ɔː ˈnʌθɪŋ ˈprɪnsɪpl/ | 全或无原则 | quán huò wú yuán zé |
| Dendrites/ˈdendraɪts/ | 树突 | shù tū |
| cell body/sel ˈbɒdi/ | 细胞体 | xì bāo tǐ |
| axon/ˈæksɒn/ | 轴突 | zhóu tū |
| myelin sheath/ˈmaɪɪlɪn ʃiːθ/ | 髓鞘 | suǐ qiào |
| Glial cells/ˈɡlaɪəl selz/ | 神经胶质细胞 | shén jīng jiāo zhì xì bāo |
| synapse/ˈsɪnæps/ | 突触 | tū chù |
| neurotransmitters/ˈnjuːrətrænsmɪtəz/ | 神经递质 | shén jīng dì zhì |
| reuptake/ˈruːpteɪk/ | 再摄取 | zài shè qǔ |
| Hormones/ˈhɔːməʊnz/ | 激素 | jī sù |
| Psychoactive drugs/ˌsaɪkəʊˈæktɪv drʌɡz/ | 精神药物 | jīng shén yào wù |
| tolerance/ˈtɒlərəns/ | 耐受性 | nài shòu xìng |
| addiction/əˈdɪkʃn/ | 成瘾 | chéng yǐn |
| withdrawal/wɪθˈdrɔːl/ | 戒断反应 | jiè duàn fǎn yìng |
| reflex arc/ˈriːfleks ɑːk/ | 反射弧 | fǎn shè hú |
A signal that is all or nothing
- A neuron does not fire a little bit harder for a stronger stimulus.
- It either fires completely or not at all — the all-or-nothing principle 全或无原则.
- Strength is coded by how often neurons fire, and how many fire, not how hard.
一个全或无的信号
- 神经元不会因为刺激更强就发放得"用力一点"。
- 它要么完全发放,要么完全不发放——这就是全或无原则(all-or-nothing principle)。
- 强度由神经元发放的频率和数量编码,而不是由力度编码。
The all-or-nothing principle means that a neuron... · 全或无原则意味着神经元……
Strength is coded by the rate · 率 of firing and the number of neurons, not the force of one firing. · 强度由发放频率与神经元数量编码,而不是由单次发放的力度编码。
The parts of a neuron
- Dendrites 树突 receive signals from other neurons.
- The cell body 细胞体 sums them and decides whether to fire.
- The axon 轴突 carries the signal away; a myelin sheath 髓鞘 around it speeds transmission up.
- Glial cells 神经胶质细胞 support and insulate neurons rather than transmitting themselves.
神经元的组成部分
- 树突(dendrites)接收来自其他神经元的信号。
- 细胞体(cell body)把这些信号加总,并决定是否发放。
- 轴突(axon)把信号传出去;包裹其外的髓鞘(myelin sheath)加快传导。
- 神经胶质细胞(glial cells)支持并绝缘神经元,自身并不传导。
Fire a neuron, step by step · 一步步让神经元放电
All-or-none: below threshold nothing happens, and above it the impulse is always the same size. · 全或无:低于阈值什么也不发生,高于阈值冲动的大小总是相同。
Glial cells transmit signals in the same way neurons do. · 神经胶质细胞以与神经元相同的方式传递信号。
Glial cells support and insulate neurons; the neurons do the transmitting. · 神经胶质细胞支持并绝缘神经元;传导由神经元完成。
Crossing the gap
- Neurons do not touch. The gap between them is the synapse 突触.
- The signal crosses chemically: neurotransmitters 神经递质 are released and bind on the far side.
- Leftover neurotransmitter is taken back in — reuptake 再摄取.
跨越那道间隙
- 神经元并不相接。它们之间的间隙是突触(synapse)。
- 信号以化学方式跨越:释放神经递质(neurotransmitters),它们在对面结合。
- 剩余的神经递质被收回——即再摄取(reuptake)。
The gap between two neurons, crossed chemically, is the ____. · 两个神经元之间以化学方式跨越的间隙叫做 ____。
Neurons do not touch; neurotransmitters carry the signal across the synapse. · 神经元并不相接;神经递质把信号送过突触。
"All-or-nothing" is about one neuron's firing, not about how strongly you feel something. A light touch and a hard press both make neurons fire identically — what differs is the rate of firing and the number of neurons involved.
"全或无"说的是单个神经元的发放,而不是你感觉有多强烈。轻触与重压都使神经元以同样方式发放——不同的是发放的频率与参与的神经元数量。
Select all · 所有 that the CED lists as consequences of repeated psychoactive drug use. · 选出 CED 列为反复使用精神药物之后果的所有项。
Tolerance, addiction and withdrawal are the named consequences; faster reflexes are not. · 耐受性、成瘾与戒断是被点名的后果;更快的反射不是。
Neurotransmitters, hormones and drugs
- Each neurotransmitter has specific functions, which can depend on where in the body it acts.
- Hormones 激素 do a similar job outside the nervous system, travelling in the blood — slower, but longer-lasting.
- Psychoactive drugs 精神药物 work by changing neurotransmitter function somewhere in this chain.
- Repeated use can produce tolerance 耐受性 and addiction 成瘾, with withdrawal 戒断反应 on stopping.
神经递质、激素与药物
- 每种神经递质都有特定功能,而这些功能可能取决于它在身体何处起作用。
- 激素(hormones)在神经系统之外做类似的工作,经血液运输——更慢,但持续更久。
- 精神药物(psychoactive drugs)的作用方式,是在这条链条的某处改变神经递质的功能。
- 反复使用会产生耐受性(tolerance)与成瘾(addiction),停用时出现戒断反应(withdrawal)。
Put the steps of a reflex arc in order. · 把反射弧的各步骤排序。
The reflex is completed in the spinal cord; the brain finds out afterwards. · 反射在脊髓中完成;大脑是事后才知道的。
The reflex arc
- In the spinal cord, the reflex arc 反射弧 shows central and peripheral neurons working together.
- A sensory neuron carries the signal in, an interneuron passes it across, a motor neuron carries the response out.
- The brain is bypassed, which is why your hand moves before you feel the pain.
反射弧
- 在脊髓中,反射弧(reflex arc)显示了中枢与周围神经元如何协同工作。
- 感觉神经元把信号传入,中间神经元把它转接,运动神经元把反应传出。
- 大脑被绕过了,这正是你的手在感到疼痛之前就移开的原因。
Many antidepressants block reuptake. The neurotransmitter that would have been reabsorbed stays in the synapse longer, so it keeps acting on the receiving neuron — the drug changed one step in the chain, not the neuron itself.
许多抗抑郁药阻断再摄取。本会被重新吸收的神经递质在突触中停留更久,因而持续作用于接收神经元——药物改变的是链条中的一步,而不是神经元本身。
A neuron fires all-or-nothing. Signals arrive at dendrites, are summed in the cell body, travel down the axon, and cross the synapse as neurotransmitters. Hormones do a slower version in the blood, and psychoactive drugs act by changing one step of this chain.
神经元以全或无方式发放。信号到达树突,在细胞体中被加总,沿轴突传导,并以神经递质的形式跨越突触。激素在血液中完成较慢的版本,而精神药物通过改变这条链条中的某一步起作用。