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welcome back to the Mr sin Channel last
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time we talked about the endocrine
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system today we are going to be going
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over unit 2 topic three of AP Psychology
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an overview of the nervous system and
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the neuron the nervous system is our
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body's primary information system for
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our thoughts voluntary actions and also
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our involuntary action think of the
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nervous system as a high-speed bullet
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train the nervous system is constantly
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sending signals at an extremely fast
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speed throughout your entire body this
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is how your body communicates and makes
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decisions all of your actions feelings
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and thoughts require your nervous system
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so you could say the nervous system is a
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pretty big deal the nervous system can
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be broken down into two main parts we
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have our central nervous system and our
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peripheral nervous system the central
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nervous system is made up of the brain
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and spinal cord this is the control
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center that gives orders to the rest of
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the body while the peripheral nervous
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system is all of the different nerves
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that Branch off from the brain and the
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spine this allows the nervous system to
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communicate with the rest of your body
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so for example when you decide to smash
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the like button on a YouTube video or
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when you consider subscribing to a
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YouTube channel it's your central
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nervous system your brain that is
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sending a message through the peripheral
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nervous system through the nerves in
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your hand and telling your hand muscles
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to move and press that button now at the
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start of this video I said that the
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nervous system is how your body
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communicates and if you're good at
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communicating with people that means
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you're not only good at speaking but
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also listening communication is a
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two-way streak the nervous system is
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similar while the central nervous system
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sends messages through the peripheral
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nervous system to tell the body what to
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do the the peripheral system can also
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send messages back when looking at the
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peripheral nervous system we can see
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that we can break it down into the
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sensory Division and also motor division
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the sensory division also known as the
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afren division focuses on conducting
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impulses from sensory stimuli to the
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central nervous system this means that
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the pns is taking information from your
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body and sending that information to
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your brain remember at the start of the
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video when I said the nervous system is
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like a high-speed bullet train while the
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afren neurons of the pns are the tracks
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the messages are being sent through that
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go straight to the brain and spinal cord
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this allows your body to constantly be
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informed about what's going on inside
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your body but also what's going on
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around your body all this information
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comes from your sensory receptors Your
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Eyes Ears Nose tongue and Skin So when
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you accidentally set your hand on a hot
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oven burner your sensory receptors in
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your hands are saying ouch and that
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message is traveling up through the
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afron pathways of your pns to your brain
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and it's telling you that you're in pain
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next is the motor division also known as
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the efr division of the peripheral
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nervous system signals here come from
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the brain and spinal cord and go out to
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the muscles and glands of your body
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through the efferent neurons these
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signals create motor or movement
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responses going back to our example of
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your hand on the burner as soon as the
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message gets to your brain your hand is
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burning your brain sends a message down
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the fer and Pathway to your hand to move
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your hand off the burner these messages
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are being sent so quickly you hardly
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have time to realize what's happening
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remember the sensory neurons also known
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as the afferent neurons send signals to
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the brain and spinal cord while the
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motor neurons and F eer at neurons send
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messages from the brain and spinal cord
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to the rest of the body the somatic
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nervous system or also known as the
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skeletal nervous system includes your
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skeletal muscles your movement and your
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five senses these movements happen
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consciously and voluntarily whenever you
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go biking play video games you are using
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your somatic nervous system you are
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consciously pushing the pedals down with
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your legs or pressing the buttons on
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your controller which is your brain
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sending signals to those muscles to move
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the autonomic nervous system controls
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your involuntary activities this system
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makes sure you keep breathing keeps your
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heart rate beating your stomach
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digesting and all those other wonderful
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bodily functions that happen in the
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background that you need to survive all
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of this happens without you having to
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consciously think about it the autonomic
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nervous system allows us to reach
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homeostasis it provides stability for
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our internal environment the autonomic
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nervous system has two divisions which
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work together especially in an emergency
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the first is the sympathetic division
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which is what gets your body mobilized
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and ready for action this is what makes
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your heartbeat faster your eyes dilate
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and your breathing increase it also
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slows down your digestion to allow for
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more energy to go where it's needed it's
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known as your fight or flight response
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the second is the parasympathetic
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division which is what relaxes your body
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this slows your heart rate increases
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your digestion and helps you focus on
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saving and storing energy this is
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commonly referred to as the rest and
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digest Okay so we've been spending a lot
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of time now talking about the central
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nervous system and also the peripheral
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nervous system and now we are going to
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start talking about the cells that make
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up these system systems the neurons and
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their helper cells gal cells gal cells
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are the most abundant cells in the
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nervous system and they support neurons
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through protection they also provide
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them with nutrients Galo cells do not
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process information meaning they do not
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send any messages or signals for your
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body neurons on the other hand are the
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basic functional unit of the nervous
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system neurons communicate with each
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other by using electrical impulses and
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chemical signals to send information
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throughout our nervous system let's take
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a minute and go over the different parts
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of the nerve cell the name of the cell
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body is called the Soma this house is
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the cell's nucleus the nucleus contains
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the genetic material including
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information for the cell to develop and
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other structures that allow the neuron
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to function extending outward from the
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Soma are dendroides which receive
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chemical information from adjacent
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neurons through receptor site the
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dendrites send this information towards
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the cell body the message then goes down
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the axon fiber this is the longest part
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of the neuron and it carries information
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away from the Soma and out through its
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terminal branches think of the axon as a
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long cable that allows the cell to send
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information away from itself to other
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cell when I say information is being
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sent down the axon it's sent in the form
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of an electrical impulse this is a
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process called an action potential we'll
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go more in depth into this process in
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our next topic review video so make sure
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you've hit that subscribe button so you
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don't miss it all right so we're almost
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done but I want to highlight a couple
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more important parts of the neuron first
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we need to go back to G cells and talk
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about how they can protect the neuron
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when it comes to protecting the neuron
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we have G cells known as Schwan cells
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which wrap around the axon and produce
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the milin sheet the mil sheath covers
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the axon and increases how fast the
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action potential travels down the axon
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and it also protects the axon from being
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damaged now there are gaps in the milein
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sheath which are called the nodes of
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ranir this is where the axon is exposed
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which helps promote the continuing
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action potential as the information and
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action potential progress down the axon
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it reaches the axon terminal it then has
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reached a meeting point between the two
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neurons this is called the synapse this
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is where the action potential releases
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neurotransmitters into the synaptic gap
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or CFT which is how information is
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further related to the receiving neuron
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this is how neurons talk to each other
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the synaptic gap is the space between
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the neurons specifically between the end
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of the axon terminal and the next
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neurons dendrite or cell body just like
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action potentials we get into the
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specifics of neurotransmitters and the
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synapse in future vide for now remember
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that the neurotransmitters are located
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at the end of the axon which is called
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the axon terminal and are released into
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the synapse so you can see that your
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nervous system is a pretty big deal this
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allows us to function and live the lives
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we live this video is just a quick
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overview of the nervous system in our
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next video we'll go into the
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neurotransmitters and the different
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types of neurons so make sure you hit
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that subscribe button so you don't miss
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out on any of that awesome content also
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if you're struggling with any of these
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different types of Concepts make sure to
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check out some of the resources in the
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description of this video and of course
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don't forget to answer the practice
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questions that have been on the screen
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and check your answers in the comment
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section below thank you so much for
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watching I'm Mr sin and until next time
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I'll see you online
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[Music]
