神经反射

2024年4月4日发(作者：)

Reflexes

完整神经活动的基本单位是反射弧。

This arc consists of a sense organ, an afferent neuron, one or more synapses in a central

integrating station or sympathetic ganglion, an efferent neuron, and an effector.

反射弧包括感受器，传入神经元，一个或几个位于中心综合站（或交感神经节）的突触，传出神经元和效应器。

The basic unit of integrated neural activity is the reflex arc.

哺乳动物传入（躯体神经元）与传出躯体神经元间的连接通常位于脑或脊髓。

The afferent neurons enter via the dorsal roots or cranial nerves and have their cell bodies in the

dorsal root ganglia or in the homologous ganglia on the cranial nerves.

传入神经元经背根或脑神经进入，其胞体位于背根神经节或相应的脑神经节。

In mammals, the connection between afferent and efferent somatic neurons is generally in the

brain or spinal cord.

传出纤维经前根或相应的运动脑神经离开。

The principle that in the spinal cord the dorsal roots are sensory and the ventral roots are motor is

known as the Bell-Magendie law.

脊髓中背根是感觉径，前根是运动径，这一规律被称为Bell-Magendie法则。

The efferent fibers leave via the ventral roots or corresponding motor cranial nerves.

传入和传出神经元轴突或肌肉产生的冲动具有 “全或无”的特性。

On the other hand, there are 3 junctions or junction-like areas in the reflex arc where responses are

graded.

另一方面，反射弧有3种接头或接头样区域，可发生分级反应。

Impulses generated in the axons of the afferent and efferent neurons and in muscle are “all or

none” in character.

它们是感受器传入神经元域，传入和传出神经元间的突触，以及肌肉神经接头。

At each of these points, a nonpropagated potential proportionating in size to the magnitude of the

incoming stimulus is generated.

在每一个连接点产生大小与传入刺激成比例的非传导电位。

These are the receptor-afferent neuron region, the synapse between the afferent and efferent

neurons, and the myoneural junction.

分级电位为电紧张（电位），可使相邻的神经或肌肉（细胞）膜发生去极化，并产生全或无的反应。

The number of action potentials in the afferent nerve is proportionate to the magnitude of the

applied stimulus at the sense organ.

传入神经中动作电位的数量与感受器受到的刺激强度成比例。

The graded potentials serve to electrotonically depolarize the adjacent nerve or muscle membrane

and set up all or none responses.

connection between the afferent and efferent neurons is usually in the central nervous system,

and activity in the reflex arc is modified by the multiple inputs converging on the efferent neurons.

传出神经的刺激强度与动作电位频率大致相关，但传入与传出神经元间的连接通常位于中枢神经系统，（因此）反射弧活动受到多个汇集于传出神经元上的刺激的修饰。

There is also a rough correlation between the magnitude of the stimulus and the frequency of

action potentials in the efferent nerve; however, the

最简单的反射弧在传入和传出神经元之间只有一个突触。

Such arcs are monosynaptic, and reflexes occurring in them are monosynaptic reflexes.

这样的（反射）弧为单突触性的，其发生的反射为单突触反射。

The simplest reflex arc is one with a single synapse between the afferent and efferent neurons.

Reflex arcs in which one or more interneurons are interposed between the afferent and efferent

neurons are polysynaptic, the number of synapses in the arcs varying from 2 to many hundreds.

传入和传出神经元间有一个或多个中间神经元插入的反射弧为多突触性的，（反射）弧中的突触数量从二个到数百个不等。

In both types, but especially in polysynaptic reflex arcs, activity is modified by spatial and

temporal facilitation, occlusion, subliminal fringe effects, and other effects.

在两种（反射弧）中，特别是在多突触反射弧中，（反射）活动受到时空性的易化、阻塞、阈下边缘效应及其他效应的修饰。