What are the main components of a neuron?

The main components of a neuron include dendrites, cell body or soma, axon (including the axon hillock), and axon terminal.

What is the function of dendrites?

Dendrites receive signals from other neurons and are involved in graded potentials.

What is an action potential?

An action potential is a rapid electrical signal that travels down the axon, initiated at the axon hillock.

What role does the axon play in neuronal function?

The axon conducts action potentials away from the cell body to the axon terminal.

What is neurotransmitter release?

Neurotransmitter release occurs at the axon terminal, allowing communication between neurons.

What are the different classifications of neurons?

Neurons can be classified structurally (multipolar, bipolar, pseudo-unipolar) and functionally (sensory, motor, interneurons).

What is the function of interneurons?

Interneurons connect sensory and motor neurons and process information within the central nervous system.

How do neurotransmitter reuptake inhibitors work?

They block the reuptake of certain neurotransmitters, increasing their availability in the synapse.

What are synaptic vesicles?

Synaptic vesicles store neurotransmitters until they are released into the synaptic cleft.

What is an EPSP and IPSP?

EPSP (excitatory postsynaptic potential) depolarizes the neuron, while IPSP (inhibitory postsynaptic potential) hyperpolarizes it.

Neurology | Neuron Anatomy & Function

00:44:33

https://www.youtube.com/watch?v=qOmmqu6_g3s

Zusammenfassung

TLDRIn this video, the structure and function of neurons are thoroughly explained, outlining key components such as dendrites, soma, axon, and axon terminals. Each component's role in the transmission of signals and communication between neurons is explored, including the process of action potentials and neurotransmitter release. The video also discusses synaptic functions like graded potentials (EPSP and IPSP) and the importance of reuptake mechanisms. Additionally, neurons are classified into multipolar, bipolar, and pseudo-unipolar types based on structure, and functionally into sensory, motor, and interneurons for effective communication within the nervous system.

Mitbringsel

🧠 Neurons consist of dendrites, soma, axon, and axon terminals.
🔗 Dendrites receive signals and are involved in graded potentials.
⚡ The axon conducts action potentials away from the soma.
🧪 Neurotransmitter release occurs at the axon terminal during synaptic transmission.
🔄 Reuptake of neurotransmitters is crucial for synaptic function.
📊 Neurons are classified into multipolar, bipolar, and pseudo-unipolar types.
💡 Interneurons connect sensory and motor pathways in the CNS.
📈 Action potentials are rapid signals along the axon.
🔋 EPSP and IPSP are critical for neuron depolarization and hyperpolarization.
🧬 Protein synthesis in the soma is essential for neuronal function.

Zeitleiste

00:00:00 - 00:05:00
The video introduces the topic of neurons, emphasizing the importance of structural and functional understanding. Viewers are encouraged to engage with the content through likes, comments, and subscriptions while providing links to social platforms.
00:05:00 - 00:10:00
The structure of neurons is explained, focusing on key components: dendrites, cell body (soma), axon, axon hillock, and axon terminals. Dendrites are characterized as the receptive zones, while the axon is responsible for conducting action potentials.
00:10:00 - 00:15:00
Dendrites' functions are explored, highlighting ligand-gated ion channels that facilitate synaptic connections. This leads to the creation of excitatory postsynaptic potentials (EPSPs) or inhibitory postsynaptic potentials (IPSPs), which are fundamental concepts in graded potentials.
00:15:00 - 00:20:00
The cell body (soma) is discussed not only for its role in receiving graded potentials but also for its critical function in protein synthesis, including neurotransmitters and membrane proteins, through processes involving DNA transcription to mRNA and translation into proteins.
00:20:00 - 00:25:00
The axon is dissected, detailing its primary role in conducting action potentials. The structure of microtubules and motor proteins (kinesin and dynein) is explained, elaborating on anterograde and retrograde axonal transport for neurotransmitter vesicles and organelles.
00:25:00 - 00:30:00
The action potential's phases are clarified—depolarization (positive charge flow) followed by repolarization (negative charge flow) with specific voltage-gated sodium and potassium channels detailed. This section reiterates the importance of the axon's conduction functions.
00:30:00 - 00:35:00
The axon terminal is described as the secretory region where neurotransmitters are released, emphasizing the mechanisms of neurotransmitter reuptake and degradation. The clinical relevance of reuptake inhibitors in managing mood disorders is also addressed.
00:35:00 - 00:44:33
Lastly, the classification of neurons is presented, distinguishing between multipolar, bipolar, and pseudo-unipolar neurons based on structure, and then transitioning into the functional classification: sensory, motor, and interneurons, explaining their roles and importance in neuronal circuits.

Mind Map

Video-Fragen und Antworten

What are the main components of a neuron?
The main components of a neuron include dendrites, cell body or soma, axon (including the axon hillock), and axon terminal.
What is the function of dendrites?
Dendrites receive signals from other neurons and are involved in graded potentials.
What is an action potential?
An action potential is a rapid electrical signal that travels down the axon, initiated at the axon hillock.
What role does the axon play in neuronal function?
The axon conducts action potentials away from the cell body to the axon terminal.
What is neurotransmitter release?
Neurotransmitter release occurs at the axon terminal, allowing communication between neurons.
What are the different classifications of neurons?
Neurons can be classified structurally (multipolar, bipolar, pseudo-unipolar) and functionally (sensory, motor, interneurons).
What is the function of interneurons?
Interneurons connect sensory and motor neurons and process information within the central nervous system.
How do neurotransmitter reuptake inhibitors work?
They block the reuptake of certain neurotransmitters, increasing their availability in the synapse.
What are synaptic vesicles?
Synaptic vesicles store neurotransmitters until they are released into the synaptic cleft.
What is an EPSP and IPSP?
EPSP (excitatory postsynaptic potential) depolarizes the neuron, while IPSP (inhibitory postsynaptic potential) hyperpolarizes it.

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Untertitel

Automatisches Blättern:

00:00:14
all right ninja nerds in this video
00:00:15
today we're going to talk about the
00:00:16
structure and function of
00:00:18
neurons all right guys before you guys
00:00:20
get started in this video please hit
00:00:21
that like button comment down in the
00:00:23
comment section and
00:00:24
please subscribe also down in the
00:00:26
description box we have links to all our
00:00:27
social media platforms for you guys to
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interact with us
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all right ninja nerds let's get started
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all right ninja so the first thing that
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we have to talk about when we're talking
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about a neuron is obviously go over the
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different structural components of a
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neuron so what makes up a neuron
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structurally
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then we got to talk about what those
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different components of a neuron
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do all right so first things first when
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you take a look at this neuron you see
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these little
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these little extensions coming off of
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this big circular structure here
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all these little extensions are called
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dendrites that's the first thing i want
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you to know
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so the extensions that are coming off of
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this neuron
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is called your dendrites these are the
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receptive zone we'll talk about what
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that means
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for a neuron next thing you have this
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big circular structure here with a whole
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bunch of stuff inside of it
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this here is called your cell body or
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your soma so this is called the cell
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body
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or also sometimes referred to as the
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soma
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the third part here of the act of the
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actual neuron is this long elongated
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portion here
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that's going to be in between the cell
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body
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and the axon terminal okay this portion
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here is called your
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axon so this third part here is called
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your axon
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now i have to add in one more little sub
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component of the axon it's important
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because it's going to come up when we
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talk about action potentials
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the part where the cell body kind of
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like narrows and goes
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into this kind of like thin axon
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structure
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is called the axon hillock so remember
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whenever you're looking at an axon like
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this if i were to draw another
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small version of it like this there's a
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part where the cell body starts to
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narrow
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that portion where the cell body kind of
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like narrows like a funnel
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this portion here is referred to as the
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axon hillock
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okay so when you're talking about the
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axon a special part to remember
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is called the axon hillock the reason
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why this area is important is because
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there's a high concentration
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of voltage-gated sodium channels there
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so whenever action potentials are
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generated they're generated here
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and move down the axon okay this last
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portion here of the neuron
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is this little kind of bulbous like
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structure here of the neuron coming off
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the axon
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and this is called the axon terminal or
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the synaptic terminal
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i'm just going to write axon terminal
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and sometimes you might even hear it
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written as axon terminal
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bulb or synaptic bulb
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there's a bunch of different synonymous
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terms there okay
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so we got all the different components
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of a neuron let's talk about what their
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functions are
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first all right so now let's go to start
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talking about the functions of these
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different
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areas of the neuron right so we talk
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about the dendrites right
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so what you want to think about here is
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that we're actually looking at one of
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these
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dendrites here coming off right and
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we're kind of going to
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cut into this right and really zoom in
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on it in this view
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so we're taking this dendrite taking a
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section of that cell membrane and
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looking at it here
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now another thing to add on to that is i
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want you to imagine this is what we're
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going to call our postsynaptic neuron
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that means that there's going to be
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other neurons that are synapsing
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on this postsynaptic neuron so let's
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imagine here that you have
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other neurons interacting at that site
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that we're going to zoom in on
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when we zoom in on that we got some
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proteins that you guys need to know
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because they're relevant to the function
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of the dendrite
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in this dendritic cell membrane part
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you have these special types of channels
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what are these special types of channels
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these channels that are present on the
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dendrites are called your ligand
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gated ion channels
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and these are important because they are
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involved in formation of epsps
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and ipsps what the heck is that zach
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i'll explain to you what that means
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these neurons
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right imagine here i have kind of like a
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little neuron here
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like a little axonic extension and it's
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releasing out a neurotransmitter
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okay that neurotransmitter
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what it's going to do is is it's going
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to come here
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and bind into this little pocket okay
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on this ligand-gated ion channel when it
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binds onto the pocket there's normally
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like a little valve if you will that's
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blocking this opening for ions to come
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in
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like this but once this little
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neurotransmitter binds onto that pocket
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it causes that valve fuel to open up and
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then allows for positive ions
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to move into the cell making the cell
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nice and positive that's called
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depolarization when you make the cell
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more positive or less negative if you
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will
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and that is referred to as a
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depolarization right when you make it
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more positive and that's called an epsp
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you're trying to stimulate the neuron to
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fire or generate an action potential and
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the other aspect let's say that you have
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another neuron over here maybe it's this
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one
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and you have the axon here and this axon
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is releasing another neurotransmitter
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but instead of this neurotransmitter
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being stimulatory let's have the
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opposing
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let's have an inhibitory
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neurotransmitter and then that
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neurotransmitter binds into this little
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pocket on that ligand-gated ion channel
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normally that channel has a valve that's
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closing it like this
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when the neurotransmitter binds it opens
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up the valve if you will
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and allows for negative ions to flow
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into the cell these negative ions make
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the inside of the cell
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more negative than it usually is it
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brings it below
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what's called resting membrane potential
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that's called
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hyperpolarization and hyperpolarization
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when you make the cell more negative
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than it usually
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is is called an ipsp
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why is this important because these
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terms collectively
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are called are involved in what's called
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your graded
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potentials and these are basically
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little
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changes in the voltage of the cell
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membrane
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to basically try to get the cell to
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develop
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the ability to generate action
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potentials so your dendrites are
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involved in graded potentials that's
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what i want you to know
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how via these ligand-gated ion channels
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there is another way though
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and it's just important for you to
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remember the second way
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the second way that it has other
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proteins here that are involved here
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is via what's called g-protein-coupled
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receptors
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we're not going to go through this
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mechanism because it's long and it's
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unnecessary
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we have other videos that cover that but
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these have g protein couple receptors
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that again imagine you have a neuron
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here releases a neurotransmitter
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that neurotransmitter binds onto this
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little receptive region of this pocket
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this jeep this uh
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receptor here when it binds onto it
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activates what's called a g
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protein and that g protein can activate
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what's called
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second messengers and these can be a
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bunch of different types
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but eventually that activates what's
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called protein kinases
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right and the whole point here is that
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these protein kinases
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can go and phosphorylate particular
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proteins that are present on the cell
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membrane
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and maybe this protein that's present on
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the cell membrane
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that's activated by these protein
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kinases
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right what that will do is that allow
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for either positive ions to flow in
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making a positive change bringing about
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an epsp
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or bringing in negative ions into the
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cell
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and if those negative ions flow into the
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cell that could be causing a
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ipsp so it's the same concept just a
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different way that they get there
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this is what dendrites do now
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not only do dendrites perform this type
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of action which are involved in graded
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potentials whether it be ligand-gated
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mediated
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or g-protein-coupled mediated cell
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bodies also do that
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so that means if you were to take a look
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and zoom in
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on that cell body and really look at it
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everything that's going to be happening
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there
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is happening here it's the same type of
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activity
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so you also will have neurons which are
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going to be interacting here
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presynaptic neurons interacting with the
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cell body okay
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so that's one thing so one thing we
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already know is that this also this cell
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body is involved in
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graded potentials
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but it has an even more significant
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function
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very important function it's involved in
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protein
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synthesis and when i talk about this
00:08:58
we'll go over
00:08:59
those literally the most basic
00:09:02
aspects of what i mean by protein
00:09:05
synthesis the process
00:09:06
but what i want you to know is when we
00:09:08
talk about protein synthesis
00:09:11
what type of proteins are we making
00:09:13
there's proteins all across this dang
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cell
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it could be neurotransmitters that
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you're actually synthesizing
00:09:19
it could be enzymes that are involved in
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particular cellular processes
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it could be membrane proteins maybe
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membrane proteins that are going to be
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voltage-gated
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ligand-gated or g-protein-coupled
00:09:32
receptors so it could be membrane
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proteins
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so it is important that this cell body
00:09:38
perform that function
00:09:39
how does all of that happen we're going
00:09:41
to briefly go through that
00:09:43
all right so when we talk about protein
00:09:45
synthesis how is all of this happening
00:09:47
we understand the process of how it's
00:09:48
involved in the graded potentials
00:09:51
which is basically designed to take
00:09:52
resting membrane potential to a
00:09:53
threshold potential to trigger an action
00:09:55
potential right we talked about that
00:09:57
but how is it involved in this protein
00:09:58
synthesis in the basic sense here
00:10:00
you have the dna inside the nucleus of
00:10:02
the cell body right
00:10:04
and that dna may have particular genes
00:10:07
that are constantly expressed and maybe
00:10:10
these proteins are for
00:10:12
voltage-gated proteins for the
00:10:14
ligand-gated maybe it's for
00:10:16
neurotransmitters enzymes whatever
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but whenever that gene is transcribed
00:10:22
we convert that into mrna right that's
00:10:26
called transcription
00:10:27
that mrna is then done it does what it's
00:10:30
then exported out of the nucleus and
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into the cytoplasm
00:10:33
and then comes to this next structure
00:10:35
here this next structure encounters is
00:10:38
called the rough endoplasmic reticulum
00:10:40
but it's important to remember that the
00:10:42
rough endoplasmic reticulum inside of
00:10:43
neurons
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is sometimes referred to as nissl bodies
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okay so sometimes you might hear the
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term nissl
00:10:51
bodies and this is basically a
00:10:53
specialized name for the rough er in
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neurons
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now this mrna may go to this rough
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endoplasmic reticulum
00:11:00
and at the rough endoplasmic reticulum
00:11:03
it'll use that mrna
00:11:05
and then translate it in other words
00:11:07
it's going to turn this
00:11:08
into a protein okay
00:11:12
so it's going to turn that into a
00:11:13
protein that protein will then be
00:11:15
packaged in the rough endoplasmic
00:11:17
reticulum and then
00:11:18
budded off to then be
00:11:22
modified and further packaged by what
00:11:25
else
00:11:26
by the golgi apparatus so then here's
00:11:29
you're going to be a little vesicle
00:11:30
coming off of the rough er
00:11:32
consisting of the proteins it'll then
00:11:34
move into the golgi apparatus
00:11:36
and in the golgi apparatus it'll undergo
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modification and then packaging into
00:11:41
vesicles where we're going to take that
00:11:42
protein and package it
00:11:45
inside of this vesicle and then bud that
00:11:48
vesicle
00:11:48
off of what is this structure here this
00:11:51
structure is called your
00:11:52
golgi apparatus right so this is your
00:11:54
golgi
00:11:57
now from here when you bud that gold off
00:12:00
the golgi you budge that vesicle off
00:12:02
the bud that vesicle off which contains
00:12:04
in it proteins let's just pretend
00:12:06
that this protein that we're
00:12:08
synthesizing here is actually a
00:12:10
neurotransmitter
00:12:12
neurotransmitters that are packaged into
00:12:14
these vesicles have to be
00:12:16
transported down the axon to that axon
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terminal
00:12:20
and we have to next we're going to talk
00:12:22
about how in the heck
00:12:24
do those vesicles containing proteins
00:12:27
and other things like organelles
00:12:28
get transported down the axon to the
00:12:31
axon terminal
00:12:32
so again we understand that this protein
00:12:34
synthesis process is what is occurring
00:12:36
in the nucleus and this may not just be
00:12:38
neurotransmitters
00:12:40
this could also be enzymes
00:12:43
or membrane proteins
00:12:48
okay that is what i want you to know
00:12:52
about the cell body okay now that we've
00:12:54
talked about that let's move on to the
00:12:55
next part which is the axon
00:12:56
so the axon this long tube between the
00:12:59
cell body and the axon terminal
00:13:01
what is its function obviously pretty
00:13:03
much anybody who's learning about this
00:13:05
knows that the primary function of the
00:13:08
axon
00:13:08
is to conduct action potentials and what
00:13:12
is an action potential
00:13:14
it's a voltage usually a positive
00:13:18
charge a flow of positive charge down
00:13:21
the axon from the cell body down the
00:13:23
axon to the axon terminal
00:13:25
right where there's a flow of positive
00:13:28
charge that's called the depolarization
00:13:30
but then following that is usually a
00:13:33
repolarizing wave
00:13:35
so when we talk about an action
00:13:36
potential there's the depolarization
00:13:39
wave and then there's the
00:13:43
re-polarization
00:13:44
wave and we'll go over that a little bit
00:13:46
later
00:13:48
and talk about what the heck that means
00:13:50
but that's the big thing we know about
00:13:51
the axon is it conducts
00:13:52
action potentials right depolarizing
00:13:55
wave down a positive charge followed by
00:13:57
a repolarizing wave of negative charge
00:13:59
the next part is the one that i actually
00:14:01
really want to talk about because it's
00:14:02
not often talked about but it's
00:14:03
clinically relevant
00:14:06
is you have this big old blue structure
00:14:07
in the middle that we're going to talk
00:14:08
about called microtubules
00:14:10
and on those microtubules are special
00:14:12
types of proteins called
00:14:13
motor proteins and these motor proteins
00:14:16
are involved in
00:14:17
transporting things up and down the axon
00:14:20
axonal transport so this purple
00:14:24
protein is actually referred to as
00:14:26
kinesin
00:14:28
and this kinesin is a what's called a
00:14:30
positive and directed motor protein
00:14:32
i don't really care about that what i
00:14:33
want you to know is that
00:14:35
it moves things we'll talk about what
00:14:37
those things those are
00:14:38
from the cell body down to the axon
00:14:41
terminal
00:14:42
so when you go cell body
00:14:46
to the axon terminal
00:14:49
that is referred to as
00:14:53
anterograde
00:14:56
axonal transport
00:14:59
to give you an idea of what kind of
00:15:01
things this would be transporting we
00:15:02
already talked about it
00:15:04
this vesicle containing
00:15:05
neurotransmitters membrane proteins
00:15:07
enzymes
00:15:07
i might have to transport that down to
00:15:09
the axon terminal so i can release it
00:15:11
or i can plug it into the membrane down
00:15:13
here or maybe i've got to take a
00:15:14
mitochondria down here because i need a
00:15:16
lot of atp to be produced down here
00:15:18
to drive some of these processes so it's
00:15:20
moving
00:15:21
organelles neurotransmitters and
00:15:22
vesicles down
00:15:24
in the the opposite situation you need
00:15:27
this little dude
00:15:28
or dudette to be taking things in the
00:15:30
opposite direction
00:15:31
so this orange protein is called
00:15:34
dynein and dynein is a minus indirected
00:15:39
motor protein
00:15:40
and this is taking things from the axon
00:15:42
terminal
00:15:44
and again it could be an axon i'm just
00:15:46
giving you the direction going from axon
00:15:48
terminal towards the
00:15:50
cell body and this when you're going in
00:15:54
that direction
00:15:55
is called retrograde
00:15:59
axonal transport
00:16:02
what kind of things would you want to be
00:16:04
transporting then
00:16:06
maybe the mitochondria has lived its
00:16:08
fine life and it's time for it to go
00:16:10
okay and it needs to be taken up and
00:16:12
either recycled or
00:16:13
or degraded maybe you want to bring up
00:16:16
some growth factors
00:16:17
up to the cell body to where the nucleus
00:16:19
is to stimulate
00:16:21
proteins that are involved there we
00:16:23
might need that
00:16:24
so that's what i want to now talk about
00:16:26
is some of those things that it carries
00:16:28
to and from and how it's clinically
00:16:30
relevant
00:16:31
all right so what do we say the axon
00:16:33
does it conducts action potentials
00:16:35
which we said if we're going down there
00:16:36
could be a positive flow of charge down
00:16:38
the axon
00:16:39
followed by a negative charge or a
00:16:41
depolarizing wave followed by a
00:16:42
repolarizing wave i want to briefly talk
00:16:44
about that
00:16:45
we're going to talk about it more in the
00:16:46
video on resting graded and action
00:16:48
potentials but
00:16:50
here on this cell membrane of these
00:16:52
purple channels and let's refer to these
00:16:53
channels that are on here as these
00:16:55
voltage
00:16:56
gated sodium channels
00:17:00
and these guys will open once you hit a
00:17:03
particular
00:17:04
voltage a threshold voltage if you will
00:17:07
once you hit that threshold voltage the
00:17:09
sodium ions will then rush
00:17:11
into this axon and when these positive
00:17:14
ions rush
00:17:15
into the axon the cell the actual
00:17:18
cytoplasm here
00:17:19
it really makes the inside of the cell
00:17:21
super positive
00:17:23
and you want to think about this is that
00:17:24
you have a flow of positive charges
00:17:27
that are moving down this axon
00:17:31
and that is where that depolarizing or
00:17:33
flow of positive charges are coming from
00:17:35
that's involved in the depolarizing
00:17:37
phase of the action potential
00:17:40
on the other hand you want the action
00:17:43
potential after you've stimulated the
00:17:45
axon in the terminal
00:17:46
you need to now relax or cause this
00:17:49
cell to go into a resting state after
00:17:52
it's been depolarized so you need a
00:17:54
negative charge to flow across
00:17:55
so that the cell can rest in order to do
00:17:58
that you need these maroon
00:18:00
channels which are called your voltage
00:18:04
gated potassium channels and these are
00:18:07
only going to be open when you hit a
00:18:09
particular threshold
00:18:11
usually after depolarization once they
00:18:13
open potassium floods out of the cell
00:18:16
when potassium floods out of the cell
00:18:18
what does that do
00:18:20
it causes the inside of the cell to
00:18:22
become extra negative
00:18:24
and now that negative charge if you're
00:18:27
kind of skipping along here step by step
00:18:29
by step
00:18:29
that negative charge is flowing down the
00:18:32
axon to the axon terminal
00:18:34
and this is called the repolarizing wave
00:18:36
so that's the involvement of the axon
00:18:39
the next thing is this transport process
00:18:41
here is your kinesin protein right so
00:18:43
here's the kinesis we'll put a k right
00:18:44
here in his body
00:18:46
what is he transporting down here well
00:18:48
imagine he's transporting what that
00:18:50
vesicle
00:18:51
and what kind of vesicle that vesicle
00:18:53
that's containing
00:18:55
multiple things proteins in general
00:18:57
right and maybe inside of this it's
00:18:58
containing neurotransmitters
00:19:00
membrane proteins enzymes that we need
00:19:03
down here
00:19:04
maybe it's also transporting
00:19:06
mitochondria because you need
00:19:07
mitochondria down there as well so maybe
00:19:10
it's also
00:19:11
transporting a mitochondria down to the
00:19:14
axon terminal
00:19:16
in the opposite situation think about
00:19:18
this this guy
00:19:19
right this is your dynein this is going
00:19:21
to be transporting
00:19:23
certain types of things back up here
00:19:25
what kind of things is it going to be
00:19:26
transporting
00:19:28
back up here maybe it's transporting any
00:19:30
vesicles
00:19:32
or mitochondria that have lived their
00:19:35
best
00:19:36
life but it's time for them to go
00:19:39
and in that situation we could be
00:19:41
transporting up
00:19:43
vesicles that contain that need to be
00:19:45
degraded or organelles that need to be
00:19:47
degraded
00:19:48
or recycled the last situation is it
00:19:51
could be carrying up something very very
00:19:53
important that i need you guys to
00:19:54
remember
00:19:56
we're going to do this in orange so you
00:19:58
don't forget it
00:20:00
it could be carrying upwards let's say
00:20:02
that for some reason there was some
00:20:04
nerve injury
00:20:05
or there's some damage to the nerve
00:20:06
terminal or the axon itself
00:20:10
and you want to tell the cell body that
00:20:13
maybe there was some damage to the
00:20:14
membrane some damage to some of the
00:20:16
proteins or something like that down
00:20:17
here
00:20:18
so what this axon terminal will do is
00:20:20
it'll send up
00:20:21
through these dynein proteins nerve
00:20:24
growth factors and this nerve growth
00:20:27
factor as it's transported by the
00:20:29
dyneins up here what can it do
00:20:31
it can then go up to the
00:20:34
cell body in the nucleus and this nerve
00:20:37
growth factor
00:20:38
may stimulate particular genes to
00:20:41
increase the expression of mrna increase
00:20:44
the translation of the mrna
00:20:46
and increase the packaging and
00:20:48
production of proteins
00:20:49
in vesicles so that we can transport
00:20:52
down here
00:20:53
more vesicles containing more proteins
00:20:55
or other different organelles
00:20:57
to help to repair or grow whatever's
00:21:00
going on down here at the axon terminal
00:21:02
or distal axon
00:21:03
isn't that cool i think it is
00:21:07
the last thing that i need you guys to
00:21:09
know here
00:21:10
is that pathogens love to plague these
00:21:12
axonal transports
00:21:14
you know there's a virus called the
00:21:16
polio virus
00:21:19
or your rabies virus
00:21:22
or your herpes simplex virus or your
00:21:25
varicella zoster virus all of these
00:21:27
viruses
00:21:28
they can basically infect your nerve
00:21:30
terminals
00:21:32
from the nerve terminals they're going
00:21:35
to try to migrate up to the cell body
00:21:36
because these are viruses they need our
00:21:38
nuclear machinery
00:21:39
to generate more viral proteins and
00:21:41
replicate they can't do that down here
00:21:43
when they infect the nerve terminal
00:21:45
so what they do is is they hitch a ride
00:21:48
with these motor proteins
00:21:49
these dyneins and then they travel
00:21:52
upwards towards the cell body
00:21:56
and then this virus if you will can then
00:21:59
use
00:22:01
our nuclear machinery to make more
00:22:03
viruses
00:22:05
destroying this neuron you know in a
00:22:07
perfect example of it going the opposite
00:22:09
direction
00:22:10
you know when someone ever gets um
00:22:12
shingles
00:22:13
right if they get like the virus the
00:22:14
varicella zoster virus
00:22:16
they get infected that virus travels up
00:22:18
here
00:22:19
uses the nuclear machinery but maybe it
00:22:21
lays dormant for a couple years
00:22:24
then from some stress immunosuppressive
00:22:26
issue
00:22:27
that virus gets activated and then it
00:22:30
starts producing tons of viral particles
00:22:32
and then it uses the kinesin protein
00:22:36
to bring that virus back down to the
00:22:38
axon terminal
00:22:40
and then from the axon terminal it gets
00:22:42
released out to the skin
00:22:43
tissue and what happens it starts
00:22:45
damaging the skin tissue
00:22:46
and you can end up with shingles so do
00:22:49
you see how pathogens can really
00:22:51
kind of use this axonal transport
00:22:53
mechanism to their advantage in a way
00:22:55
all right so that's why i wanted us to
00:22:57
know that all right let's talk about the
00:22:58
axon terminal
00:23:00
all right so the next thing that we have
00:23:01
to talk about is the axon terminal the
00:23:03
axon terminal i just want you to
00:23:05
remember that this is the secretory
00:23:07
region
00:23:08
what in the heck does that mean that
00:23:11
this is where
00:23:12
neurotransmitters are released
00:23:16
also not only is it the area where
00:23:18
neurotransmitters are released
00:23:20
it is also very very important where
00:23:23
there is the
00:23:24
re-uptake of
00:23:27
neurotransmitters that are involved here
00:23:29
i can't stress that enough
00:23:31
the re-uptake of particular
00:23:32
neurotransmitters will apply a very
00:23:34
quick clinical
00:23:35
relevance to that but now let's talk
00:23:37
about how it's involved in the secretory
00:23:39
region how it's involved in this
00:23:40
neurotransmitter release
00:23:41
and then how it's involved in reuptake
00:23:42
and talk about a quick clinical
00:23:44
relevance to that so this depolarizing
00:23:47
wave of action potentials because of
00:23:48
this
00:23:50
voltage-gated sodium channels that are
00:23:51
allowing for sodium to rush in and move
00:23:53
down the axon
00:23:54
to the axon terminal that voltage
00:23:57
stimulates these voltage-gated calcium
00:23:59
channels
00:24:00
so this is going to be your
00:24:00
voltage-gated calcium channels
00:24:04
now what happens
00:24:07
is once this is stimulated calcium will
00:24:10
rush
00:24:10
into this axon terminal when calcium
00:24:14
rushes into the axon terminal there's a
00:24:15
very significant reason
00:24:17
you know what's on these vesicles that
00:24:18
we talked about which were consisting of
00:24:20
what
00:24:21
neurotransmitters in there right
00:24:24
consisting within the vesicle they have
00:24:26
particular proteins that are
00:24:28
embedded on their vesicular membrane and
00:24:31
on the plasma membrane of this axon
00:24:33
terminal
00:24:34
these are called snare proteins the
00:24:36
snare protein that's present here
00:24:38
on the vesicle are called v snares
00:24:42
and if you truly want to know it they're
00:24:44
called synaptobrevin
00:24:46
and synaptotagmin the other one here on
00:24:49
the actual cell
00:24:50
membrane of the axon terminal is called
00:24:51
your t snares
00:24:54
and this is consisting of syntaxin and
00:24:56
snap25 if you truly want to know that
00:24:59
but what happens is is that calcium is
00:25:02
the bridge between the v
00:25:04
snares and the t snare so once it comes
00:25:06
in it binds to these little
00:25:08
v snares and t snares and acts as a
00:25:10
liquid linkage
00:25:12
and pulls the vesicle to the cell
00:25:14
membrane
00:25:15
and fuses the vesicular membrane with
00:25:17
the plasma membrane of the terminal
00:25:19
and what does that look like afterwards
00:25:21
look at this look at how cool this is
00:25:23
fuses with it and it looks like this
00:25:27
once that happens now all of these
00:25:29
neurotransmitters which are located in
00:25:31
the vesicle are now
00:25:32
open to be released out in the synapse
00:25:35
and maybe out in the synapse
00:25:36
is another neuron right maybe there's
00:25:39
another neuron out here and it has
00:25:41
particular receptors present on that
00:25:43
cell membrane
00:25:45
that that neurotransmitter will go and
00:25:47
bind to
00:25:49
and carry out maybe the same process
00:25:50
we've talked about to this point
00:25:52
here's the important point once that
00:25:54
neurotransmitter has exerted
00:25:56
its effect on this other cell whether
00:25:58
that be another neuron
00:25:59
another muscle whatever that
00:26:01
neurotransmitter has to be degraded
00:26:04
or taken out of that synapse and there's
00:26:08
two main ways that you remove
00:26:10
neurotransmitters from a synapse
00:26:12
so neurotransmitter termination if you
00:26:15
will
00:26:17
is done by two ways i consider here
00:26:20
one is by re-uptake
00:26:24
and the other one is by degradation so
00:26:26
you have an enzyme
00:26:27
sitting in the synapse that degrades
00:26:30
that neurotransmitter
00:26:31
the one that's really pertinent here
00:26:33
that you guys need to know
00:26:36
is this reuptake because that's where
00:26:38
the axon terminal comes in
00:26:40
let's say that neurotransmitter after it
00:26:41
binds with this receptor it does its
00:26:43
function
00:26:44
then what happens is we have to get that
00:26:47
neurotransmitter back into this
00:26:49
axon terminal to incorporate it back
00:26:52
into this vesicle
00:26:53
how do we do that we use this reuptake
00:26:56
protein
00:26:56
so you use a re-uptake protein present
00:26:59
here
00:27:00
to move that neurotransmitter
00:27:03
back in to the axon terminal
00:27:07
and then maybe from there maybe it has
00:27:08
to go undergo a couple enzymatic steps
00:27:11
but either way it'll get put back into
00:27:13
the vesicle
00:27:14
and recycled that's important why is
00:27:17
that important
00:27:19
let's say this neurotransmitter is
00:27:21
serotonin sometimes it's
00:27:22
written as 5-hydroxytryptamine 5-ht
00:27:27
the reuptake protein would be called a
00:27:29
serotonin
00:27:30
reuptake protein if you give a drug
00:27:34
called s s r eyes
00:27:38
selective serotonin reuptake inhibitors
00:27:41
like
00:27:41
zoloft lexapro all of those things uh
00:27:46
prozac those are going to inhibit
00:27:49
these reuptake proteins why is that
00:27:51
important
00:27:52
now that neurotransmitter can't be
00:27:54
brought back into this actual axon
00:27:56
terminal
00:27:56
and it sits out in this synapse
00:27:58
continuously stimulating this cell
00:28:00
that could be important whenever that
00:28:03
excess 5-hydroxytryptamine is needed to
00:28:05
improve
00:28:06
mood in people with depression anxiety
00:28:08
obsessive-compulsive disorders
00:28:10
so that's why this is so important that
00:28:12
you know sometimes the basic
00:28:13
functions of these components of the
00:28:15
neuron all right that covers axon
00:28:16
terminal
00:28:17
all right so we talked about the basic
00:28:19
structure and functions of the different
00:28:20
parts of the neuron now what we have to
00:28:22
remember is that when we talk about
00:28:23
neurons
00:28:24
and we might use a lot of this
00:28:25
terminology throughout the process of
00:28:27
all the neurology
00:28:28
videos in our playlist is that you have
00:28:31
to know how the neurons are classified
00:28:33
less commonly they're used in a
00:28:35
structural classification more commonly
00:28:37
especially throughout the process of all
00:28:38
the videos that
00:28:39
you guys are going to watch it's going
00:28:40
to be more functional classification
00:28:42
that we're going to talk about
00:28:44
so to get this part out of the way
00:28:46
because it is a little boring i'm not
00:28:47
going to lie to you
00:28:48
let's just talk about what these things
00:28:49
are and where you can find them so the
00:28:51
first one here is this multipolar neuron
00:28:54
so let's just write these out this is
00:28:55
your multi-polar neuron
00:28:58
and i'll explain why in a second this
00:28:59
one here is called your bipolar neuron
00:29:03
okay this is called your bipolar knot
00:29:04
and this last one over here
00:29:06
is called your pseudo unipolar neuron
00:29:12
and i'll explain why all of this and
00:29:13
then we'll talk about where you can find
00:29:14
them and why that
00:29:15
why you'd be finding them there so the
00:29:17
multipolar neurons the reason they're
00:29:19
called that it's very simple
00:29:21
look at how many dendritic extensions i
00:29:22
have coming off if i have three
00:29:25
plus dendritic extensions coming off
00:29:26
that's enough for me to call this a
00:29:28
multipolar neuron
00:29:29
multiple dendritic extensions with a
00:29:31
cell body and an axon extension that's a
00:29:33
multipolar
00:29:34
if i only see one dendritic extension
00:29:38
so one dendritic extension we'll put de
00:29:41
and one axon coming from the cell body
00:29:43
that's a bipolar neuron
00:29:45
it's not hard right pseudo-unipolar is
00:29:48
really
00:29:48
weird it doesn't really have a dendrite
00:29:51
and it doesn't really have like a
00:29:52
distinguishable
00:29:54
axon with a terminal kind of thing it
00:29:56
has here
00:29:57
your peripheral process so here's the
00:29:59
cell body
00:30:01
okay here's the cell body of it then you
00:30:04
have this process coming from the cell
00:30:06
body
00:30:06
usually out to your periphery so we call
00:30:09
this the peripheral
00:30:12
process and then this
00:30:16
part from the cell body going towards
00:30:18
the central nervous system
00:30:20
we call this part the central
00:30:23
process so pretty straightforward
00:30:27
okay now the important thing is to know
00:30:29
where you can find these things and
00:30:31
why you would generally find them there
00:30:33
for the most part
00:30:34
multipolar neurons think about it they
00:30:36
have tons of dendrites what does that
00:30:37
mean what does dendrites do
00:30:39
they're the receptive region so they
00:30:41
have to receive signals from multiple
00:30:42
neurons all over the
00:30:44
place think about the primary motor
00:30:46
cortex who does he have to receive
00:30:48
information from because that's an
00:30:49
example of a multipolar neuron
00:30:51
he would have to receive information
00:30:53
from your basal ganglia your basal
00:30:56
ganglia
00:30:56
they have to send information to your
00:30:58
motor cortex you know your sensory
00:31:00
cortex
00:31:01
it has to send information to the motor
00:31:02
cortex you know your cerebellum
00:31:05
it has to send information to your motor
00:31:07
cortex what else would send information
00:31:10
there
00:31:10
you also have other motor areas which
00:31:12
called your pre-motor cortex and your
00:31:14
supplementary motor cortex would have to
00:31:15
send information there
00:31:16
so it has to have all these receptive
00:31:18
regions and then
00:31:20
have a axon that goes down to your
00:31:23
spinal cord
00:31:24
that's an example of a multipolar neuron
00:31:26
multiple receptive regions with an axon
00:31:28
going down
00:31:30
same thing this is literally the same
00:31:31
concept your cerebellum
00:31:33
so obviously if we were to give an
00:31:34
example here just pick motor cortex
00:31:38
as one example the second example
00:31:42
pick your cerebellum and if we're really
00:31:45
being specific about what type of
00:31:47
neurons they actually give these neurons
00:31:48
in the motor cortex they call them
00:31:50
pyramidal cells and those cerebellum we
00:31:52
call them
00:31:53
purkinje cells if you truly want to know
00:31:55
that
00:31:56
i want you to get the basic concept
00:31:57
though where is the information multiple
00:31:59
receptive regions
00:32:01
your spinal cord picking up sensations
00:32:03
proprioceptive sensation
00:32:05
picking up information about your
00:32:07
equilibrium from your inner ear
00:32:10
picking up information from your motor
00:32:12
cortex about the particular
00:32:14
motor plan that you have to move all of
00:32:16
that has to go to the cerebellum
00:32:18
and then the cerebellum from there can
00:32:19
send its information to tons of
00:32:21
different areas
00:32:22
but you see how there's multiple
00:32:23
receptive regions and then an axon
00:32:25
extension
00:32:26
that's an example of multipolar neurons
00:32:29
bipolar neurons are really weird and you
00:32:31
find these mainly in your special
00:32:33
sensory organs which ones the retina
00:32:37
has bipolar neurons we talk about
00:32:40
really where like what they do because
00:32:42
these don't really generate action
00:32:43
potentials they generate what's called
00:32:44
graded potentials
00:32:45
we talk about that in our special
00:32:46
sensors special senses playlist
00:32:49
the other one is your olfactory
00:32:51
epithelium which are present in the the
00:32:53
roof
00:32:54
of the nasal cavity so the uh also the
00:32:57
ol
00:32:58
factory nerves
00:33:02
they're also examples of bipolar neurons
00:33:04
and then one more
00:33:06
is your inner ear particularly
00:33:09
like the vestibule and the semicircular
00:33:11
canals
00:33:12
are also example of bipolar neurons
00:33:16
so best way to remember this is mainly
00:33:17
your special sensory organs is really
00:33:20
where you'll find
00:33:21
bipolar neurons the last one is your
00:33:24
pseudo unipolar your pseudo unipolar is
00:33:26
actually very important i really want
00:33:27
you to remember this one
00:33:30
the main area where you're going to hear
00:33:32
them tons and tons and tons of times
00:33:33
throughout the neurology playlist
00:33:35
is your dorsal root ganglion your dorsal
00:33:38
root ganglion which is located
00:33:41
outside of your spinal cord so here is
00:33:44
going to be what's called the cell body
00:33:45
that part there
00:33:47
it has a peripheral process we said
00:33:50
right
00:33:51
that peripheral process may be going to
00:33:54
the skin let's just put here skin we're
00:33:56
just going to write skin
00:33:57
picking up sensations from the skin
00:33:59
taking it down this peripheral process
00:34:02
to where the cell body is then into the
00:34:04
central process and from here it may
00:34:06
synapse somewhere in your
00:34:08
spinal cord or go up to your brain okay
00:34:12
so this is an example of the
00:34:15
pseudo-unipolar neuron but it's located
00:34:17
outside of the peripheral nerve outside
00:34:19
of the central nervous system
00:34:21
and a bunch of cell bodies located
00:34:24
outside of the peripheral nervous system
00:34:26
are called a ganglia and since it's near
00:34:28
the dorsal
00:34:30
root that's why we call it a dorsal root
00:34:32
ganglia
00:34:33
all right beautiful last but not least
00:34:37
is certain cranial nerves have
00:34:39
pseudo-unipolar neurons
00:34:41
classical example classical is cranial
00:34:44
nerve
00:34:45
five the cranial nerve five tried
00:34:48
which is your trigeminal nerve your
00:34:50
trigeminal
00:34:52
ganglion this is a
00:34:56
perfect example you know there's a
00:34:58
ganglia that sits here inside kind of
00:35:00
like outside within the skull base here
00:35:02
and it has three divisions one is called
00:35:04
a ophthalmic division
00:35:06
a maxillary division and a mandibular
00:35:08
division right
00:35:09
but they're picking up sensations all
00:35:11
from the face
00:35:12
those sensations travel down their
00:35:14
peripheral processes
00:35:16
to the cell body from the cell body you
00:35:19
have a central process that goes into
00:35:20
the central nervous system
00:35:22
to the nucleus inside of your brainstem
00:35:24
which is your trigeminal nucleus
00:35:26
that's another example of a
00:35:28
pseudo-unipolar neuron all right
00:35:29
beautiful
00:35:30
that's the structural classification
00:35:32
let's hit the functional more important
00:35:33
one
00:35:34
all right so we talked about the
00:35:35
structural classification of neurons now
00:35:36
let's talk about the one that you're
00:35:38
probably going to hear a lot of
00:35:39
throughout the process of our neurology
00:35:41
lectures which is the functional
00:35:42
classification
00:35:43
so when we talk about neurons they can
00:35:44
be sensory neurons
00:35:46
motor neurons or interneurons now what
00:35:48
the heck does that mean
00:35:49
i want to establish some terminology
00:35:51
here so
00:35:53
sensations it can pick up sensations
00:35:55
from your viscera
00:35:56
maybe sensations from the lungs from the
00:35:59
heart from the git from the urogenital
00:36:01
tract
00:36:02
those visceral sensations are going from
00:36:05
these organs
00:36:06
to your actual central nervous system in
00:36:08
this case the
00:36:09
brain or the spinal cord so that's
00:36:11
called afferent information so sensory
00:36:14
information is also referred to as
00:36:16
afferent
00:36:18
information so you can have neurons that
00:36:19
are taking sensory information or
00:36:20
afferent information
00:36:22
to your cns but since this is coming
00:36:24
from the viscera
00:36:26
we give this a special term which is
00:36:28
called general
00:36:29
visceral afferent neurons this is terms
00:36:33
that will come up later in the lectures
00:36:34
okay
00:36:35
it's important to know that one the next
00:36:38
one is you could be picking up
00:36:39
sensations
00:36:40
from your skin or from your skeletal
00:36:43
muscles
00:36:44
or from your joints your ligaments all
00:36:47
of those
00:36:47
areas this is somatic sensation so when
00:36:50
it's somatic meaning it's coming from
00:36:52
skin
00:36:52
muscle joints when i mean muscle i mean
00:36:55
skeletal muscle
00:36:56
okay joints ligaments that sensory
00:36:59
information can be taken to your brain
00:37:01
or spinal cord
00:37:02
but that is called general somatic
00:37:06
afferent fibers okay
00:37:09
next one you could be having sensory
00:37:11
information being conducted from your
00:37:14
special sensory organs which are going
00:37:16
to be responsible for
00:37:17
vision and hearing if this
00:37:21
is traveling towards your actual central
00:37:23
nervous system and it's coming from a
00:37:24
special sensory organ
00:37:26
very particular here from the eyes or
00:37:29
ears
00:37:29
this is called special sensory afferent
00:37:32
fibers
00:37:33
ssa fibers okay
00:37:37
last but not least if the sensations
00:37:39
that are being
00:37:40
taken to your central nervous system
00:37:42
affair and information through these
00:37:44
sensory neurons
00:37:45
are coming from your smell or from taste
00:37:49
and going to your central nervous system
00:37:51
that is a special sense
00:37:52
but it's more visceral so it's called
00:37:55
special
00:37:56
visceral afferent neurons
00:37:59
so these are terms that i want you to
00:38:01
understand whenever they come up in
00:38:03
future lectures
00:38:05
all right the next one is the motor
00:38:08
neurons
00:38:09
motor neurons are taking efferent
00:38:12
information that means they're going
00:38:13
away from the central nervous system
00:38:16
and going to the effector organ here
00:38:19
in this case it could be going to
00:38:22
your visceral organs maybe it's going to
00:38:26
the smooth muscle within the respiratory
00:38:27
bronchi
00:38:28
maybe it's going to the cardiac muscle
00:38:30
within the heart maybe it's going to
00:38:32
glance
00:38:33
which are going to be present all in
00:38:35
different places
00:38:37
that type of information is autonomic
00:38:39
information
00:38:40
but it's visceral and it's motor and
00:38:43
it's going away from the central nervous
00:38:46
system
00:38:46
so these fibers that are going to be
00:38:48
motor fibers from central nervous system
00:38:50
to viscera
00:38:51
for smooth muscle cardiac muscle and
00:38:53
gland activity is called
00:38:55
general visceral efferent neurons
00:39:00
the motor neurons that are going from
00:39:01
the central nervous system
00:39:03
away towards the effector organ in this
00:39:05
case
00:39:06
skeletal muscle right skeletal muscle
00:39:10
this is somatic function so this is
00:39:12
called
00:39:13
general somatic efferent
00:39:16
neurons which are taking motor
00:39:18
information from the central nervous
00:39:19
system to skeletal muscles
00:39:22
last but not least the ridiculous ones
00:39:24
here they love to give extra names to
00:39:26
make everything complicated for us
00:39:28
but there's going to be nerves that go
00:39:31
to special muscles
00:39:32
around the head and neck area that are
00:39:35
carried
00:39:35
by a couple different nerves cranial
00:39:37
nerve 5 which is your trigeminal nerve
00:39:40
cranial nerve seven which is your facial
00:39:43
nerve
00:39:44
cranial nerve nine which is your
00:39:46
glossopharyngeal nerve
00:39:48
and cranial nerve 10 which is your vagus
00:39:50
nerve
00:39:51
these will supply muscles
00:39:54
of the head and neck region from a
00:39:57
particular
00:39:58
embryological uh thing called your
00:40:01
pharyngeal arches
00:40:03
and really the best way to remember them
00:40:05
is correlating with the nerve
00:40:07
so cranial nerve five supplies the first
00:40:09
pharyngeal arch
00:40:10
cranial nerve seven plus supplies the
00:40:12
second pharyngeal arch
00:40:13
glossopharyngeal supplies the third
00:40:15
pharyngeal arch
00:40:17
and then the vagus supplies the fourth
00:40:20
and the sixth sixth
00:40:23
pharyngeal arch and again these are
00:40:25
skeletal muscles
00:40:27
but they're muscles that are basically a
00:40:29
part of the head and neck that are
00:40:30
derived from these embryological origin
00:40:33
and so we don't call them general
00:40:34
somatic efferents we got to be
00:40:36
complicated and call them special
00:40:38
visceral efferent neurons all right
00:40:41
beautiful
00:40:42
let's move on to the last part all right
00:40:44
so the last functional classification of
00:40:46
neurons is interneurons
00:40:47
it's literally what it sounds like it's
00:40:50
the neurons between
00:40:52
the sensory neurons and the motor
00:40:54
neurons that's it
00:40:55
so i want you to think think about this
00:40:56
we have that motor cortex right
00:40:59
up in the uh the cerebral cortex in your
00:41:01
frontal lobe
00:41:02
this motor cortex is going to send its
00:41:04
motor fibers down and it technically
00:41:06
goes to
00:41:07
neurons in your spinal cord right lower
00:41:09
motor neurons and that goes out to your
00:41:11
skeletal muscles
00:41:12
right but this is the motor pathway this
00:41:14
entire red line is your motor pathway
00:41:18
coming from maybe the skin or maybe even
00:41:20
from the actual muscle itself because
00:41:22
you have receptors there as well
00:41:24
you can have these particular sensory
00:41:28
receptors that are taking information
00:41:30
in and when they go in this is your
00:41:33
sensory fiber here
00:41:34
it may stop off on a particular neuron
00:41:38
in between the motor and the sensory now
00:41:41
what is this one
00:41:42
this is a particular nucleus we'll talk
00:41:43
about later in another video
00:41:45
for right now i just want you to think
00:41:46
about it as just kind of a relay neuron
00:41:49
so if this is a relay neuron let's
00:41:51
actually switch the color here let's
00:41:52
make this green so we know the
00:41:53
difference here
00:41:55
this relay neuron may fire some action
00:41:58
potentials
00:42:00
to another relay neuron and then that
00:42:03
relay neuron may fire some action
00:42:05
potentials
00:42:06
to this motor to the actual motor cortex
00:42:08
right
00:42:09
so think about this you have your
00:42:11
sensory fibers which are taking
00:42:12
sensations into your central nervous
00:42:14
system
00:42:15
they may be going up and then dropping
00:42:17
off on some relay neurons
00:42:19
which will then go back and stimulate
00:42:20
your motor neurons you see how that's in
00:42:22
between here
00:42:23
that's called your interneurons to give
00:42:25
you kind of an idea so that you
00:42:27
can see that i'm not making these things
00:42:29
up this later we'll talk about is in the
00:42:31
medulla a part of your dorsal column
00:42:33
medial meniscus pathway this is called
00:42:36
your nucleus
00:42:38
like gracilis and nucleus cunaitus
00:42:42
right so these are going to be two that
00:42:43
you'll talk about that's an example of
00:42:45
an interneuron
00:42:46
your thalamus you know your thalamus has
00:42:49
tons of different nuclei
00:42:52
and it also has the ability to send its
00:42:54
action potentials to the motor cortex as
00:42:56
well
00:42:57
so it's important to realize that we're
00:42:59
talking about interneurons
00:43:01
these interneurons make up most of your
00:43:03
central nervous system
00:43:04
and commonly we only refer to them into
00:43:06
the spinal cord but they're all
00:43:08
throughout that brain and brain stem
00:43:09
baby
00:43:10
so to give you the classic example of an
00:43:13
interneuron
00:43:13
with the spinal reflex it's pretty
00:43:15
straightforward think about this
00:43:17
you have a sensation coming from the
00:43:20
skin
00:43:21
someone touches your skin that sensation
00:43:23
then does what it moves via the sensory
00:43:26
neuron
00:43:27
into the spinal cord from that it acts
00:43:30
on a
00:43:31
interneuron that
00:43:34
intern neuron then sends information to
00:43:37
what
00:43:38
to your motor neuron and that motor
00:43:40
neuron will send that information
00:43:42
out to the skeletal muscle to maybe
00:43:44
cause you move because maybe you
00:43:46
pricked your finger off of something it
00:43:48
hurt and you had to move it away
00:43:49
so you see how the interneuron is
00:43:51
involved in between that pathway this is
00:43:53
the classic situation
00:43:54
but also remember that it's present up
00:43:56
here in that brain and brainstem baby
00:43:57
all right so that's the intern neurons
00:43:59
and that covers neurons in general
00:44:01
all right all right nizhner so in this
00:44:02
video we talk about the structure and
00:44:04
function of neurons i hope it made sense
00:44:06
i hope that you guys
00:44:07
liked it guys we thank you appreciate
00:44:09
you for being awesome ninja nerds as
00:44:11
always until next time
00:44:22
[Music]
00:44:32
you