What is a Neuron? Parts and Function
Summary
TLDRThis educational video delves into the anatomy of a neuron, the fundamental unit of the nervous system. It explains the roles of dendrites in receiving chemical messages via neurotransmitters, the soma's function in integrating these signals, and the axon's role in conducting electrical impulses. The video also highlights the significance of the myelin sheath in speeding up neural signals and the nodes of Ranvier that facilitate rapid signal transmission. Different neuron types, such as motor, sensory, and interneurons, are briefly introduced, each serving distinct functions within the nervous system.
Takeaways
- 🧠 A neuron is a nerve cell that forms the nervous system and facilitates the transmission of information throughout the body.
- 🌐 Dendrites are branched structures that receive messages from other neurons through neurotransmitters.
- 🔄 Neurons communicate using chemical messages called neurotransmitters, such as dopamine, acetylcholine, and endorphins.
- 🏢 The soma, or cell body, contains the nucleus and genetic material of the neuron and is responsible for sustaining its life.
- 🚀 The axon hillock is a critical structure that, if the signal is strong enough, generates an electrical charge known as an action potential.
- ⚡ The axon carries the action potential to the end of the neuron, and its length can vary from a few millimeters to several feet.
- 🛡️ The myelin sheath is an insulator that covers the axon, increasing the speed of the electrical signal and is formed by glial cells or Schwann cells.
- 🤺 Multiple sclerosis is a disease that disrupts the myelin sheath, hindering the communication of information within the body.
- 🔑 Nodes of Ranvier are gaps in the myelin sheath that allow the action potential to jump from node to node, increasing the speed of signal transmission.
- 🔗 Axon terminals or synaptic buds are where neurotransmitters are stored and released into the synapse to bind with the receptors of the next neuron.
- 🌈 Neurons can vary in appearance and function, including motor neurons, sensory neurons, and interneurons, each with distinct roles in the nervous system.
Q & A
What is a neuron and why is it important?
-A neuron is an individual nerve cell that constitutes the nervous system, enabling the transmission of information throughout the human body. It is crucial for various functions including muscle movement, sensory detection, decision-making, and comprehension of speech.
What are dendrites and what is their function in a neuron?
-Dendrites are small branches of a neuron that receive messages from other neurons in the form of chemical signals called neurotransmitters.
How do neurons communicate with each other?
-Neurons communicate through chemical messages known as neurotransmitters, which are released by one neuron and bind to receptors on the dendrites of another neuron.
What is the role of the soma in a neuron?
-The soma, or cell body, of a neuron contains the nucleus and genetic material. It is responsible for sustaining the life of the neuron and integrating and interpreting the signals received by the dendrites.
What is the axon hillock and why is it significant?
-The axon hillock is a small structure that connects the soma to the axon. It is significant because it generates an electrical charge called an action potential if the signal is strong enough.
Describe the function of the axon in a neuron.
-The axon is a long tube-like structure that carries the electrical signal, or action potential, from the neuron to the end of the neuron or to other cells.
What is the myelin sheath and how does it affect the speed of nerve signals?
-The myelin sheath is a protective layer that covers the axon and acts as an insulator. It helps speed up the nerve impulse by allowing the electrical signal to 'jump' from one node of Ranvier to the next, rather than traveling continuously along the axon.
What is the difference between myelinated and unmyelinated axons?
-Myelinated axons are covered by a myelin sheath, which speeds up the transmission of nerve signals. Unmyelinated axons lack this sheath and are generally slower in transmitting signals.
What are the nodes of Ranvier and how do they contribute to the speed of nerve impulses?
-The nodes of Ranvier are small gaps in the myelin sheath where the electrical signal can 'jump' from one node to the next, a process known as saltatory conduction, which increases the speed of nerve impulses.
What is the function of the axon terminal?
-The axon terminal, also known as synaptic buds, is the end of the axon where neurotransmitters are stored in synaptic vesicles. When the action potential reaches the axon terminal, these neurotransmitters are released to bind to receptors on the next postsynaptic neuron.
What is the synapse and how does it relate to the communication between neurons?
-The synapse is a small gap or junction between two neurons where the neurotransmitters are released from the axon terminal of one neuron and bind to receptors on another neuron, facilitating communication between them without direct contact.
What are the different types of neurons and their functions?
-There are several types of neurons including motor neurons that control muscle movement, sensory neurons that detect information from the environment, and interneurons that link motor and sensory neurons. Each type has a specific role in the nervous system.
Outlines
🧠 Understanding Neurons and Their Functions
This paragraph introduces the concept of neurons, emphasizing their role as the fundamental units of the nervous system. Neurons are responsible for transmitting information throughout the body, enabling a wide range of functions from muscle movement to sensory perception. The video script explains that neurons communicate via chemical messengers known as neurotransmitters, which bind to dendrites, the branch-like structures of neurons. The dendrites receive messages from other neurons, and these messages are then integrated and interpreted by the soma, or cell body, which contains the neuron's nucleus and genetic material. The soma's role is crucial for sustaining the neuron's life. The paragraph also introduces the axon hillock, a structure that initiates an electrical charge called an action potential if the incoming signal is strong enough. This action potential travels down the axon, a long tube-like structure that can vary greatly in length, from a few millimeters to several feet.
🔋 The Structure and Speed of Neuronal Transmission
The second paragraph delves into the mechanics of how neurons ensure fast transmission of signals. It discusses the myelin sheath, an insulating layer that covers the axon and is produced by glial cells or Schwann cells. The myelin sheath acts like an insulator, speeding up the electrical signal's travel along the axon. The paragraph also explains the difference between myelinated and unmyelinated axons, noting that most neurons in the central and peripheral nervous system are myelinated for quick communication. The color of the myelin sheath is highlighted, with myelinated axons appearing white, which is the basis for the term 'white matter' in the brain. The paragraph further explains the nodes of Ranvier, gaps in the myelin sheath that allow for a faster transmission of action potentials along the axon through a process known as saltatory conduction. Finally, the paragraph describes the axon terminals or synaptic buds, where neurotransmitters are stored in synaptic vesicles and are released into the synapse, the junction between two neurons, to communicate with the next neuron in the chain.
Mindmap
Keywords
💡Neuron
💡Dendrites
💡Neurotransmitters
💡Soma
💡Axon
💡Axon Hillock
💡Myelin Sheath
💡Nodes of Ranvier
💡Synapse
💡Axon Terminal
💡Motor Neuron
💡Sensory Neuron
💡Interneuron
Highlights
Neurons are individual nerve cells that make up the nervous system and allow information to travel throughout the human body.
Dendrites are the branch-like structures that receive messages from other neurons through neurotransmitters.
Neurotransmitters are chemical messengers like dopamine, acetylcholine, and endorphins that transmit signals between neurons.
The soma, or cell body, contains the nucleus and genetic material of the neuron, sustaining its life.
The axon hillock generates an electrical charge called an action potential if the signal is strong enough.
The axon is a long tube that carries the electrical signal from the soma to the end of the neuron.
The myelin sheath is an insulator that covers the axon, speeding up the transmission of electrical signals.
Multiple sclerosis is a disease that disrupts the myelin sheath, affecting communication through the body.
Axons can be myelinated, which are covered by myelin, or unmyelinated, which lack a myelin sheath.
White matter in the brain is made up of myelinated axons, giving it its characteristic white color.
Nodes of Ranvier are gaps in the myelin sheath that allow action potentials to jump from node to node, increasing speed.
Axon terminals, or synaptic buds, are where neurotransmitters are stored and released to bind to receptors of the next neuron.
The synapse is the small gap between two neurons where neurotransmitters are released and bind to receptors.
Neurons can vary in appearance, with motor neurons, sensory neurons, and interneurons having distinct structures and functions.
Motor neurons are typically bipolar and help move muscles, while sensory neurons detect information from the environment.
Interneurons are found in the retina and help link motor and sensory neurons.
Transcripts
[Music]
all right guys in this video we're going
to talk about the parts of a neuron and
for some background information remember
a neuron is an individual nerve cell
that makes up the nervous system it
allows information to travel throughout
the human body so whether you want to
move your muscles detect things in the
world that are hot or cold speak make
decisions or even understand what i'm
saying all of that cannot be done
without a healthy functioning neuron so
let's go over how it works the first
structure i want to focus on are these
little branches right here it's almost
like the little fingers on my hand these
are called
dendrites what are they called
dendrites so all of these
little branches
are dendrites and what do dendrites do
dendrites receive the message from
another neuron
the way we communicate is through
language and words right but neurons
communicate through chemical messages
specifically things called
neurotransmitters
imagine for example this is a
neurotransmitter there's many types it
could be dopamine which is a reward
seeking right pleasure neurotransmitter
it could be acetylcholine which controls
our muscles it could be endorphins which
is a pain reliever this is going to be
released by another neuron and it's
going to bind
on the dendrites it's going to be
received like a lock and key this
dendrite this dendrite this your android
whichever it is it's going to bind to
that
receptor site
now once it binds it's going to be
integrated and interpreted by this area
right here called the
soma
or cell body and the soma is where you
can find the nucleus right the genetic
material of the neuron it helps sustain
life of the neuron as well
now before information travels down this
long tube right here notice that the
soma connects to this tube by this
little structure right here okay
this is what we call
the axon
hillock okay axon hillock and this is
important why is it important
if the signal is strong enough okay
we'll talk about that in another video
if the if the information is strong
enough what's going to happen is this is
going to generate an electrical charge
called an action potential and here is
our electrical charge
there we go right here okay and that's
going to start in the axon hillock
and that's going to travel down this
long tube right here what is that tube
called
this is called and is in here the axon
and the cool thing about the axon is
that it could be very very tiny just a
few millimeters in the brain to up to a
few feet long let's say going from your
spinal cord to your toes so the axon
carries the electrical signal the active
potential down here
to the end of the neuron
now this is important
you want things to go fast right if
you're an emergency something in danger
you want that charge to go really fast
on the axon well how do we ensure that
it's a fast signal
the axon is covered by something called
the mylon or mylon sheath okay the mylon
sheath
you might have heard the words
glial cells or schwann cells a lot of
this means essentially the same thing
you have glial cells or more
specifically schwann cells that form or
make this mylon and the mylon acts as an
insulator right it's like kind of like a
a wire to a wire with rubber tubing
around it helps protect and speed up
that impulse so it goes really fast and
just for some background information if
you've ever heard of something called
multiple sclerosis right this horrible
disease that affects communication
through the body it disrupts the myeloma
it destroys the myeloma so information
doesn't get from point a to point b
now not every axon has nylon right in
fact we can kind of divide this into two
types we can say there are you know
unmyelinated
unmyelinated
axon and then there's also
myelinated axon
okay myelinated
most of there we go there's a d
myelinated ammonite most of the neurons
in the nervous system central peripheral
are
myelinated why because we need things to
happen very quickly but of course there
are axons that are unmyelinated now the
color of it and this is actually
interesting to know
is the color is white okay now why is
that important
okay if we know anything about gray
matter and white matter in the brain
well white matter in the brain is
essentially made up of myelinated axons
okay that's what gives it the color
white if you've ever heard of gray
matter okay in the brain
it's called gray matter essentially
because it's the color gray because
those are unmyelinated okay there aren't
any axons that have myelom so there's
some
interesting background on the myelinated
verse on myelinated now there is another
way to make this action potential go
even faster down the axon and how is
that you notice these little tiny gaps
between the mylon okay
these gaps are what we call the nodes
of
ranvier or ranvier i always see
different names for it all right so
these are these little tiny gaps in the
mylon okay do you ever take a rock and
skip it across the water and it just
goes
right these are what the nodes do right
so here's our action potential and when
you have myelinated axons instead of
going through the axon
what happens is they bounce from node to
node and this helps speed up the process
even more so instead of going through
goes bounce bounce bounds all the way to
the end of the axon all right so what is
the end of the axon
these little branches here are what we
call the axon terminal or you might say
synaptic buds there's always so many
names for all these things axon terminal
okay
and this is where let's get back to our
neurotransmitters our neurotransmitters
are stored in synaptic vesicles and
what's going to happen is once the
exponential hits there these are going
to be released
and bind to receptors of the next
postsynaptic neuron now two neurons
don't actually touch each other it's
going to be released into an area called
the synapse is a small gap or junction
between two neurons and that's going to
bind to receptor of another neuron so
there we go there's the parts or main
parts of a neuron now it is important to
note
not all neurons look the same even
though they have roughly the same parts
they could look very different so for
example this first one is what we call a
motor neuron you can see it actually is
the typical neuron that you would see if
you google something like that right
another oh another word for motor neuron
is a multi-multi-polar
neuron okay you can have let's say a
sensory neuron
okay
sensory neuron and this is actually
another word is unipolar
neuron
and you can even have something called
an interneuron
okay
and this would be considered a bipolar
neuron right so many different names and
you could find bipolar neurons in the
retina okay in your eye next to the
ganglion cells so motor neurons would
help move my muscles right afferent or
efferent that exit the brain help me
move sensory neurons detect information
from the environment right hot cold
smells and sites and interneurons
connect or help a link the motor and
sensory neurons
all right guys thanks for watching i
really hope you learned something don't
forget to like the video subscribe i'll
see you next time
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