未登录,请登录后再发表信息
最新评论 (0)

自主神经系统:交感神经与副交感神经

Autonomic Nervous System: Sympathetic vs Parasympathetic, Animation

自主神经系统(ANS)
The Autonomic NervousSystem or ANS
为神经系统一部分 调控内脏器官的活动
is the part of the nervous system that regulates activities of internal organs.
ANS在很大程度上是自主的
The ANS is largely autonomous
不受意识的控制
acting independently of the body’s consciousness and voluntary control.
有两个主要的组成部分
It has two main divisions,
交感神经系统(SNS)和副交感神经系统(PSNS)
Sympathetic(SNS) and Parasympathetic (PSNS),
在需要机敏力和能量的情况下
in situations that require alertness and energy,
譬如面临危险或剧烈运动时
such as facing danger or doing physical activities,
ANS刺激它的交感神经部分来调动身体采取反应
The ANS activates its sympathetic division to mobilize the body for action.
交感神经系统可以增加心脏供血量
This division increases cardiac output,
加快呼吸速率
accelerates respiratory rate,
释放储存的能量
releases stored energy
和扩大瞳孔
and dilates pupils.
同时 它还抑制了在紧急情况下次级重要的机体活动
At the same time, it also inhibits body processes that are less important in emergencies,
例如消化和排尿
such as digestion and urination.
另一方面 在正常安静状态下
On the other hand, during ordinary situations,
副交感神经部分负责储存能量和促进机体的休整恢复
the parasympathetic division conserves and restores.
它可以减慢心率
It slows heartbeats,
降低呼吸速率
decreases respiratory rate,
刺激消化
stimulates digestion,
帮助排泄和储存能量
removes waste and stores energy.
交感神经部分也因此被称为
The sympathetic division is therefore known as
战斗或逃跑反应
the Fight-or-Flight response,
然而副交感神经系统与
while the parasympathetic division is associated with
休息和消化状态有关
the rest and digest state.
尽管在同一脏器上有相反的影响
Despite having opposite effects on the same organ,
但SNS和PSNS并不是彼此排斥
the SNS and PSNS are not mutually exclusive.
体内大多数组织器官都同时接受着交感神经和副交感神经的双重支配
In most organs,both systems are simultaneously active,
产生一个活动的经行速率名为
producing a background rate of activity called
——交感神经状态
the autonomic tone,
在交感神经和副交感神经输出中存在平衡
a balance between sympathetic and parasympathetic inputs.
这种平衡会
This balance shifts one way or the other
随着身体需求的变化而改变
in response to the body’s changing needs.
然而部分脏器只接受来自一个系统的支配
Some organs, however, receive inputs from only one system.
像血管的平滑肌
For example, the smooth muscles of blood vessels
只存在交感神经纤维
only receives sympathetic fibers,
来保持它们的局部收缩状态
which keep them partially constricted,
从而维系基本血压
and thus maintaining normal blood pressure.
提高产生交感神经冲动的频率
And increase in sympathetic firing rate
导致进一步收缩
causes further constriction
和提高血压
and increases blood pressure.
当减少纤维速率扩大血管时
While a decrease in firing rate dilates blood vessels,
血压下降
lowering blood pressure.
交感神经通路
The autonomic nerve pathways
起自中央神经系统的控制中心
from the control centers in the central nervous system
到目标脏器 由两种神经组成
to the target organs are composed of two neurons
它们相遇联会于神经中枢
which meet and synapse in an autonomic ganglion.
因此这些神经被称为
Accordingly, these neurons are called
节前神经和节后神经
preganglionic and postganglionic.
在SNS 前神经节神经起自胸阔和
In the SNS, the preganglionic neurons arise from the thoracic and
脊髓纤维粗隆部位
lumbar regions of the spinal cord.
这些纤维出自脊髓神经
Their fibers exit by way of spinal nerves
到达临近的神经中枢交感链
to the nearby sympathetic chain of ganglia.
在锁链上节 前神经纤维会遵循三种路线
Once in the chain, preganglionic fibers may follow any of three routes,
一些近期突触快速联合节后神经
some fibers synapse immediately with post ganglionic neurons,
一些在联合前上行或下行
some travel up or down the chain before synapsing,
另一通过锁链不经行联合
some pass through the chain without synapsing.
这三组续连为内脏神经
This third group continues as splanchnic nerves
到达内脏外旁系神经中枢
to nearby collateral ganglia for synapsing instead.
在神经中枢的节后神经纤维
From the ganglia, long postganglionic fibers
一直到目标脏器
run all the way to target organs.
SNS有一个高度的神经分叉
The SNS has a high degree of neuronal divergence.
节前神经纤维可联合多达20支节后神经
One preganglionic fiber can synapse with up to 20 postganglionic neurons.
因此SNS的影响趋于广泛
Thus, effects of the SNS tend to be widespread.
在PSNS 节前神经起自脑干
In the PSNS, the preganglionic neurons arise from the brainstem
和脊髓神经的骶髓区域
and sacral region of the spinal cord.
节前纤维 经行数个脑神经出脑干
Preganglionic fibers exit the brainstem via several cranial nerves
经行脊髓神经 出脊髓索
and exit the spinal cord via spinal nerves
在脊神经的盆骨部位前形成
before forming the pelvic splanchnic nerves.
副交感神经中枢坐落于目标脏器旁或内部
Parasympathetic ganglia are located near or within target organs.
因此节后纤维比较短
So postganglionic fibers are relatively short.
神经分支和PSNS的程度
The degree of neuronal divergence and the PSNS
远远低于SNS
is much lower than that of the SNS.
因此相较于SNS
Thus the PSNS produces more specific,
PSNS产生更加具体的局部应答
localized responses compared to the SNS.

发表评论

译制信息
视频概述

总体了解自主神经的概况

听录译者

来吧!尉英俊

翻译译者

妧.

审核员

审核员_XY

视频来源

https://www.youtube.com/watch?v=D96mSg2_h0c

相关推荐