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IB Diploma Programme · IB Diploma · Biology · HL נושא 24 3:50 קריאת קול באנגלית · תרגום אנגלי + סינית שרוף בתוך הסרטון
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תרגום טקסט
A stronger stimulus can increase impulse frequency while each action potential 动作电位 remains a similar size.
更强的刺激可以增加冲动频率，而每个动作电位的大小基本保持不变。
An action potential is a brief change in membrane potential involving voltage-gated ion channels.
动作电位是涉及电压门控离子通道的膜电位短暂变化。
Depolarization followed by repolarization propagates along a neuron.
去极化随后复极化沿神经元传播。
At a chemical synapse, transmitter release can alter the next cell membrane potential.
在化学突触处，神经递质释放可改变下一个细胞的膜电位。
An action potential is defined as a brief propagating change in membrane potential.
动作电位是指膜电位的短暂传播性变化。
A synapse is defined as a junction for communication between cells.
突触是指细胞间通讯的连接点。
The all-or-none principle applies to an individual action potential.
全或无原则适用于单个动作电位。
Stimulus information can be encoded by frequency and recruitment.
刺激信息可通过频率和募集来编码。
Myelination permits saltatory conduction between nodes rather than making ions move freely through myelin.
髓鞘化使跳跃式传导在郎飞结之间进行，而非让离子自由穿过髓鞘。
In the lab: Interpret supplied voltage-time traces and compare time intervals.
在实验室中，解读提供的电压-时间曲线并比较时间间隔。
Identify threshold, rising phase and recovery before explaining ions.
在解释离子之前，先识别阈值、上升相和恢复期。
Use classroom models rather than electrical stimulation of people.
使用课堂模型，而非对人的电刺激。
Known: 30 impulses occur in 0.50 seconds.
已知：在0.50秒内发生30次冲动。
Frequency equals count divided by time, which is 30 divided by 0.50, equaling 60 Hertz.
频率等于计数除以时间，即30除以0.50，等于60赫兹。
This is impulse frequency, not an estimate of propagation speed.
这是冲动频率，而非传播速度的估计值。
Your turn: 24 impulses occur in 0.40 s.
轮到你了：0.40秒内发生24次冲动。
Find impulse frequency.
求冲动频率。
Pause the video and work it out.
请暂停视频，自己算一算。
Check: 24 divided by 0.40 seconds is 60 impulses per second, 60 hertz.
核对：24 ÷ 0.40 秒，得每秒 60 次冲动，即 60 赫兹。
A neurotransmitter diffuses across the synaptic cleft.
神经递质扩散穿过突触间隙。
An action potential does not jump intact through the liquid gap.
动作电位无法完整地跨越液体间隙跳跃。
Excitatory input does not guarantee the postsynaptic cell reaches threshold.
兴奋性输入并不能保证突触后细胞达到阈值。
Not true: A stronger stimulus always makes each action potential larger.
这种说法不正确。 更强的刺激并不总是使每个动作电位变大。
Action potentials are all-or-none: once threshold is reached, the impulse has a fixed size set by the ion gradients.
动作电位是全或无的。 一旦达到阈值，冲动的幅度就由离子梯度决定，保持固定不变。
A stronger stimulus raises the frequency of impulses, not their amplitude.
更强的刺激会提高冲动频率，而不是增大其振幅。
An action potential is a brief change in membrane potential involving voltage-gated ion channels.
动作电位是涉及电压门控离子通道的膜电位短暂变化。
The all-or-none principle applies to an individual action potential.
全或无原则适用于单个动作电位。
Watch for: A neurotransmitter diffuses across the synaptic cleft; an action potential does not jump intact through the liquid gap.
请注意：神经递质会扩散通过突触间隙；而动作电位不会完整地跨越液体间隙跳跃。
21 impulses occur in 0.30 seconds.
在0.30秒内发生21次冲动。
Find the frequency.
求频率。
This is not the propagation speed.
这不是传播速度。
The result is an impulse frequency of 70 per second.
结果是冲动频率为每秒70次。
Once the membrane passes the threshold of minus 55 millivolts, sodium ions flood in and the potential rises.
膜电位一旦超过负55毫伏的阈值，钠离子大量流入，电位上升。
Potassium ions then leave, and a refractory period follows.
随后钾离子流出，接着是不应期。
Two records have 30 impulses in 0.5 s and 30 impulses in 1.0 s.
两条记录分别在0.5秒内产生30次冲动，在1.0秒内产生30次冲动。
Compare frequency.
请比较频率。
Would either observation determine nerve conduction speed?
这两种观察结果能否确定神经传导速度？
The frequencies are 60 and 30 hertz.
两个频率分别是 60 赫兹和 30 赫兹。
Frequency is count per time; speed requires propagation distance and delay between locations.
频率是单位时间内的次数；传导速度需要传播距离和两处之间的时间延迟。
These are different measured quantities.
二者是不同的测量量。
Pause and check yourself. Explain each point on screen in your own words, then change one number in the last example and say which assumption must still hold.
暂停一下，自我检查：用自己的话解释屏幕上的每个要点，再改动最后一个例子中的一个数字，说明哪个假设仍然必须成立。