Neurology Spinal Cord Introduction

Author:

Armando Hasudungan

Keywords:

Neurology (Medical Specialty),Medicine (Field Of Study),Spinal Cord,efferent neuron,sensory neuron,meninges,pia mater,dura,arachnoid,lecture,tutorial,summary,structure,anatomy and physiology,somatic and autonomic neuron,differences between,nervous system,central,peripheral,dorsal and ventral root,spinal cord anatomy,spinal nerves,thoracic cervical,lumbar,sacral,nerve,membrane,fasicle,epineurium,perineurium

Subtitles:
automatically on biology and medicine videos please make sure to subscribe join the Foreman group for latest videos please raise awareness again and hear please like in this video we will talk about the spinal cord we know the spinal cord is part of the central nervous system with the brain the spinal cord is connected to the brainstem which then connects the brain up on the top there now the spinal cord is uniformly organized and is divided into five regions some people save for either way on each of these regions have a number of paired of spinal nerves coming out of them so what I mean by this is for example the first region of the spinal cord is known as a cervical region and this has eight pairs of spinal nerves coming out so these red things there are spinal nerves coming out eight pairs the thoracic region has 12 pairs of spinal nerves the lumbar region has five pairs of spinal nerves the sacral region also has five pairs of spinal nerves and there is another region where we have one pair of spinal nerves these nerves are known as the coccygeal nerves because they're sort of close to the cox us spine of the spine so if we do our awesome mathematics we can see that we have 31 pairs of spinal nerves which equates to 62 spinal nerves so each of these regions of the spinal cord each of these five regions of the spinal cord are actually different in shape so if we were to take a cross-section of the cervical region here it would look something like this but before we continue on the person I draw on the right we are looking at him from a posterior view we're looking at his spinal cord from a posterior view from the back but the cross-sections of the spinal cord I am we're looking at it from an anterior view so please know that the cross-sections I'm drawing in spinal cord now are we're looking at it from an anterior view so anyway this is what a cervical region of the spinal cord would look like and here we have a pair of spinal nerves attacked attaching to this spinal cord the spinal nerve consists of a ventral root the front root and a dorsal root the back root which connects to the spinal cord the spinal cord itself consists of a gray matter in the middle and white matter surrounding it the hole in the center is known as the central canal which contains cerebrospinal fluid which helps in nourishing the nervous tissue and we should know what the grey and white matter is because that's that was taught in the previous neurology videos now if we were complete to compare the cervical region of the spinal cord to the thoracic region of the spinal cord the thoracic region would look a much rounder in shape and remember we're looking at it from an anterior view and the lumbar region on the other hand looks a bit like a more of a pyramid shape not only that but the lumbar region of the spinal cord has a much thicker gray matter compared to the other regions so as you can see the regions of the spinal cord are all different in shape and old to have different thickness of the gray matter for example but all of these regions contain spinal nerves so let's just learn a bit more about spinal nerves and about its anatomy um the spinal nerves which connect to the spinal cord is part of the peripheral nervous system you can say because it carries information between the central nervous system and periphery because it brings information to the central nervous system to the spinal cord and also takes information from the central nervous system from the spinal cord so let's just zoom into the spinal nerve here to learn a bit more about the anatomy so here we have the spinal nerve the nerve is surrounded by a membrane known as an epi neuro neom we also find blood supply here and also many bundles of neuron which make up what's called a fascicle the fascicle if we pull one out also consists of a membrane called the peri neuro Neum now as mentioned these fascicles they contain many neurons let's just pull one out here we have a neuron which is surrounded by an endo uranium another membrane this neuron this neuron is also wrapped by Schwann cells containing myelin and so this is a myelinated axon of the neuron I hope that makes sense and as we know myelinated axons they generate faster impulses so now that we know a bit more about the spinal nerve let's just go back to the spinal cord and look at what sort of membranes if have and let's learn a bit more about its anatomy by doing this let's just take a cross-section of the spinal cord of the thoracic region now this spinal cord I'm drawing which is part of the thoracic region it can represent any any section of the spinal cord but I'm just doing this for simplicity because the spinal cord is so important and it's part of the central nervous system it of course has to have some form of protection some form of barrier and it does it has three layers of protection from the most inner membrane it has the pia mater then it has the arachnoid membrane then it has the dura mater and the three make up what is known as the meninges which serve as a protective barrier of the central nervous system against harmful things the central canal the central canal which also contains the cerebrospinal fluid also is a form of protection for the spinal cord as the cerebrospinal fluid also acts like a shock absorber in the central nervous system now back to the spinal cord section coming out of each side of the spinal cord region we have spinal nerves right we know that to make this easier we can draw a line here and say that the spinal cord is part of the central nervous system and the spinal nerves are part of the peripheral nervous system the spinal nerve that is part of the peripheral nervous system consists of a ventral root the front root and a dorsal root the backward but both are connect to the spinal cord and both also join up with each other to form a big spinal nerve the dorsal root containers also a dorsal ganglion we can also have another ganglion here which we will discuss about later on ganglion is basically a location where synopsis can occur and also where where cell bodies are located it's basically bundles of neurons but anyway the dorsal root of the spinal nerve is always for is always for sensory neurons and these are where sensory neurons are so sensory neurons bring in sensory information to the spinal cord via the dorsal root here and then it will synapse with another neuron in the central nervous system in the spinal cord which will then which this new neuron will then bring this sensory information to the brain or the brain stem or somewhere in the central nervous system for processing for interpretation so what I mean is that all sensory neurons from the periphery such as this sensory neuron I am drawing with myelin wrapping around it this will receive some form of sensory stimulation be a touch pain pressure or whatnot this will bring this sensory information to the central nervous system through the dorsal root of the spinal nerve the sensory neurons body is located in the dorsal ganglion here then the sensory neuron will pass on the information to the second neuron the second neuron will then bring this sensory information to the brain or brain stem for processing for realizing that there is some sensory information coming to to the body now if the dorsal root is for sensory neurons bringing in sensory information to the central nervous system that means the ventral root is for the efferent neurons for the motor neurons so for example signals or commands from the brain or brain stem will come down to a particular location in the spinal cord and then these neurons will then sign apps with efferent neurons here also known as motor neurons which will bring this command this information um somewhere to a target tissue now this efferent neuron this motor neuron is actually a somatic neuron which means that it is bringing information or commands to initiate movement so it's going to bring information commands to skeletal muscle for contraction for example and this neuron therefore is voluntary because we can control movement it is a somatic neuron ever there is another type of neuron um another type of efferent neuron that can bring information out of the central nervous system this neuron will in red will actually stop over in this ganglion and synapse with another effort neuron this efferent neuron is or motor neuron is known as an autonomic neuron because it is part of the autonomic nervous system it is controlled involuntary it will bring information or bring commands from the central nervous system to our tissues target cells and tissues such as cardiac muscle cells smooth muscle cells and certain glands or all glands because we know how we have no control over these types of cells now let's just look at it as a summary we have the central nervous system where we have the spinal cord and within the spinal cord we have neurons that carry sensory information and also carry commands within the spinal cord then we have the peripheral nervous system which consists of two types of neurons we have the sensory neurons and we have the efferent neurons also known as the motor neurons the sensory neurons bring information to the central nervous system whereas the efferent neurons take information from the central nervous system to a target cell to a target tissue to the periphery so here we're looking at the efferent neurons so commands are information from the central nervous system will travel via efferent neurons efferent neurons can be either somatic meaning that they are voluntary or autonomic meaning that they're involuntary and this all depends on what a type of targets tissue or cell it's going to so I hope you enjoyed this video it's only an introduction to the spinal cord I'll have another video that will go into a bit sort of a bit more detail and it might be even easier than this one so look forward to that and I'll probably provide a link thank you for watching

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