Transcript for:
Understanding Neurons and Their Structures

[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