Name: 神經系統--生物速成課程#26 (The Nervous System - CrashCourse Biology #26)
Uploaded: 2021-01-14T04:21:21.000Z
Duration: 12 min 4 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

I don't really spend a lot of time thinking about my bodily functions.

But in the next few episodes, I'm going to be talking

about all of the organ systems that make our lives possible,

And to start it all off, I'm going straight to mission control:

Pretty much every animal, except for some really simple ones,

because it's what lets things do things like: have behaviors.

It makes you the sentient, living thing that you are.

The whole set-up here: your brain, your nerves,

is made up of specialized cells that you don't find

Most of those are neurons, which, you've seen them before,

they look kind of like a tree with roots, a trunk and branches.

pathways that transmit electrochemical signals

I love it when there's pizza in the video...

The receptor neurons in my taste buds recognize

I'm eating something salty and fatty and awesome.

And they carry that information along a nerve pathway to my brain.

And then my brain can be like "Yeah! Pizza!"

and then it can respond by sending back information

through different nerve pathways that say:

I'm going to try to not eat any more of that pizza.

You wouldn't think that it's terribly complicated

to know that pizza tastes good and to tell someone to eat more pizza.

and our nervous systems are crazy complicated.

Your nervous system basically has a big old bureaucracy of neurons,

and it's divided into two main departments:

the central nervous system and the peripheral nervous system.

basically your brain and your spinal cord,

is responsible for analyzing and interpreting

all those data that your peripheral nervous system,

all of the nerves outside of your brain and spine,

Once the central nervous system makes a decision about data,

it sends a signal back through to the peripheral nervous system

Which the peripheral nervous system then does.

Both of these systems contain two different types of neurons:

Afferent and efferent are biological terms,

and they're horribly confusing, and I apologize

on behalf of the entire institution of biology for them.

Afferent systems carry things to a central point,

and efferent systems carry things away from a central point.

So afferent neurons carry information to the brain

afferent neurons are called sensory neurons,

and they're activated by external stimuli

like the complex and glorious flavor of pizza

and then they convert those data into a signal

The central nervous system has afferent neurons too,

and there they bring information into special parts of the brain,

like the part of the brain that goes, "Mmmmmm, salty!"

Efferent neurons carry information out of the center.

they're called motor neurons because many of them

carry information from the brain or spinal cord

but they also go to pretty much every other organ in your body,

thus making them, like, work and do stuff to keep you alive.

In the central system, efferent neurons carry information

from special parts of the brain to other parts

Of course if it ended there, it would be way too simple

and no good bureaucracy just has two departments.

So the peripheral nervous system is actually made up of

two different systems with two very different jobs:

the somatic nervous system and the autonomic nervous system.

The somatic system controls all the stuff you think about doing

like all the information coming through your senses,

and the movement of your body when you want it to make movements.

Since we're totally in love with our brains

as sort of the center of all being, of ourselves,

everything going on in our bodies goes to our brains

Sometimes, like when we touch a hot stove,

the afferent neurons carry the signal "HOT!"

to the central nervous system, but that information

the spinal cord actually makes that decision

sends a message directly back to the muscle saying,

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神經系統--生物速成課程#26 (The Nervous System - CrashCourse Biology #26)

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